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Virtual Center for Educators of Seniors Jaroslav Kortus

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2. 4 4 4 Messages Messaging is very important ability how can be clients informed about state of application All the time when client uses application must be informed what is happening especially when any problem occurs For messaging between server and client JavaServer Faces provides a central mechanism Messages can be generated from almost every type of component that is involved in the request processing For example validators converters UlComponents and so forth When a message is generated it is either associated to a specific UI component like an input field that contains invalid data or it is associated to the whole component tree JSF maintains a message queue inside the FacesContext that stores the messages so they can be rendered during the render response phase page 28 Messages are represented through instances of the FacesMessage class which contains fields for a summary a more detailed message and a severity level according to the type of the message 4 4 5 Navigation Navigating the client browser between different views based on user gestures is one of the fundamental tasks a web application has to handle Although it is a very basic task it can become very complex to keep track of all paths that lead from one view to another The developer has to spend a lot of work in form of pure Java code or JSTL tags to define which view the application should present to the user for example after processing the submitted form
3. Validation testing follows integration tests verifies fulfilment of reasonable expectations of customer validation criteria Validation tests are per formed by black box methods Alpha tests as well as beta tests are both accomplished Alpha tests are realized by customer in the environment of supplier whereas the beta test will be executed by customer in service conditions Summary of results achieved in course of alpha part is available on page 96 5 System testing A set of tests that verify the entire system including hardware peo ple Security testing This test tests immunity of the system against an unauthorized attack Tester in hacker s role try to penetrate into the application If he has enough time and resources he succeeds The objective of developers is the biggest costs of the penetration Recovery testing System testing which verifies if all the faults were corrected in a proper time For auto error handling reinitialization checkpoint mechanism data recovery and restarting are evaluated Stress testing System testing on base of extreme load in light of quantity frequency or content Tester measures the time until the application breakdown 10 4 2 1 Test reports Accent is put on comparison between requirements and quality of the results How are require ments realized and how much the real application differs from them Important approaches about rectification of invalid parts wi
4. A command line built in tool that is an extension of the Ant tool developed by the Apache Software Foundation verifier A command line tool to validate Java EE deployment descriptors Sun Java Application Server contains some few components such as several containers or sup port for security transaction and web services This work is using last available version of Application Server version 9 0 Sometimes I met the problem about poor quality of documen tation Except the salaried books I can recommend only 31 Simple install and user s manual about Sun Java Application Server you can find in Appendix 12 1 Not only application server but also database server I needed to choose before I could start developing and testing Virtual Center On the market are also many of database servers Java can use nearly each of them because of using uniform access to databases over database connectors 9 4 2 MySQL For exemplary purposes I used MySQL database server in version 5 0 24a and MySQL Java connector version 5 0 3 For accessing database from web application were 1 Started MySQL server Install and User s tutorial will be in Appendix 12 1 2 Populated database in database server 3 Connected database with Netbeans IDE 4 Included MySQL connector library into Virtual Center Similar proceeding can be used by another database servers too MySQL has very good user s and developer s documentation at home site http www mysql or
5. MyDB database has been already created MyDB will contain for example table of animals in ZOO Troja in Prague and another table with pavilions ibidem Creating a DataSource Creating of DataSources phase depends on using Application Server In addition DataSources and work with Application servers in general is not aim of this work and so I ll refer readers to some resource engaged with using application server In the following text Pll presume created data source with name jdbc BookDB A simple tutorial about adding connection pool and JDBC data source to Application Server is a component of installation manual in second part of thesis 93 Defining Persistence Unit Persistence Unit is defined by persistence xml file which is packaged with the application WAR file This file includes following XML elements 1 lt xml version 1 0 encoding UTF 8 gt 2 lt persistence version 1 0 3 xmlns http java sun com xml ns persistence 4 xmlns xsi http www w3 org 2001 XMLSchema instance 5 gt 6 lt persistence unit name MyDBPU transaction type JTA gt 7 jta data source jdbc myDB jta data source 8 lt properties gt 9 lt persistence unit gt 10 lt persistence gt Figure 5 3 persistence xml example e persistence element that identifies the schema which descriptor validates against and includes a persistence unit element persistence unit element defines the name of a persistence unit and transacti
6. data analysis data representation technology frameworks tools e Design database design component design graphical user interface design testing schedule acceptance test specification 53 54 CHAPTER 7 INTRODUCTION e Implementation self implementation unit tests designing including test processing e Testing and Installation installation manual installation on customer validation and system testing presentation of the application and documentation delivery e Support bug fixies by agreement usability modifications functionality improvements technical support by agreement All these parts are several component parts of project documentation Common methodology for describing all over the development process is UML Unified Modeling Language The UML is a standard language for specifying visualizing constructing and documenting the artifacts of any system without an Exception of software system As well the UML is going to be a standard for software development all over the world for a long time that was one but not the only reason why I have made a decision for applying them For more details about UML or project documentation in general you can read some of references 27 28 or 7 I have extracted from Chapter 8 Basic Study 8 1 User Profiling of the Virtual Center This chapter is dedicated to gather most of information about modern t
7. the user ID and password information can easily be decoded Some of these affairs can be diluted when secure transport mechanism such as SSL or security at the network level such as the IPSEC protocol or VPN strategies is used in conjunction with BASIC authentication process 6 5 Specifying a Security Constraint Specifying a Security Constraint contains from following parts 6 5 1 Specifying a authorized users First of all developer or application administrator has to specify an authorized user on Appli cation Server For standard user of the application with rights restrictions on management of a Application Server can be new user specify in file realm This can be made simply with v Web Services A Application Server gt Configuration gt Security Realms gt file 8 Custom MBeans D PP Resources New File Realm User OK Cancel lt Z Configuration Create new user accounts forthe currently selected security realm Web Container Indicates required field 2 EJB Container User ID jan novak P 2 Java Message Service Name of a user to be granted access to this realm name can be up to Y 8 Security 255 characters must contain only alphanumeric underscore dash or dot characters y G Realms Password admin realm f file Confirm eeeeeecccee a certificate Password gt C JACC Providers Group List teacher P E Audit Modules Separate multiple groups w
8. Other most popular Java Application servers are Apache Tomcat http tomcat apache org JOnAS http jonas objectweb org or JBoss http labs jboss com 9 4 1 Java Sun Application Server The Sun Java System Application Server Platform Edition 9 0 is the full name of open source Java application server developed by Java community like fully compliant implementation of the Java EE 5 platform I just doesn t mentioned support for the Java EE 5 security model Application server can be configured for working with the users groups or roles There can be as well configured secure HTTP Some features specific for the Application Server are 9 4 SERVER ENVIRONMENT 69 e message security e single sign on across all Application Server applications within a single security domain e programmatic login Application Server includes a number of Java EE tools that are not part of the Java EE 5 platform but are provided as convenience to the developer I used only a small fragment of them There are the most frequently used Admin Console A web based GUI Application Server administration utility By developing with Netbeans it is almost not necessary to use it because Netbeans IDE contains very good compensation for its A screenshot of Admin Console is shown on Figure 6 1 on page 49 asadmin A command line configuration utility used for start and stop Application Server and for manage users resources and applications asant
9. Session beans SessionBeanl data shared all over the session As well I used this session for some parameter passing because the reguest beans are very limited see next section part about the Page navigation UserProfile information about actually logged user such as user s ac cess rights user s username last user s login user prefer ences Password is not stored within this session because of possible security risk class representation of component tree of the page Most im portant parts of all the page beans are init method ini tializing UI components init method is called as the first when the page is navigated to or when some event occurs for example prerender method called before render response phase is performed This is good place for redirecting an re quest for example destroy callback method that is called after rendering is completed for this request if init was called regardless of whether or not this was the page that was actually rendered Destroy method is good place for re leasing of reserved resources Page beans contain only data needed for one response life cycle init and destroy are typical for all Java Beans Session and Request Beans has in addition activate and passivate prerender and preprocess callback methods are in Netbeans environ ment typical only for Pages Beans Pages beans lt lt page bean gt gt Table 11 1 Implemented JSF source
10. Short example is on Figure 1 1 e Servlet name wildcarding in DD up to date it is not necessary to insert filter for every servlet separately Wildcard character is in Java EE allowed see Figure 2 5 line 18 16 lt filter mapping gt 17 lt filter name gt Image Filter lt filter name gt 18 lt servlet name gt lt servlet name gt lt New gt 19 lt filter mapping gt Figure 2 5 Filter for all the Servlets e Restriction removal The specification no longer prevents an error page handler from producing a non error response 2 8 Why Servlets overrun CGI There are the biggest advantages of Java Servlet compared to CGI scripts according to 14 18 and 17 Portability Servlets are portable because Java is portable due to byte code and inter preters and because servlets conform to the well defined widely accepted Java API Power JDK Java Development Kit is a part of Java EE technology including all the useful classes and interfaces that developers using by designing standard Java applications Servlet has access to this classes in the same way like standard Java application Efficiency and Endurance After servlet s initialization by calling init method result ing object persists over time and over all requests for the Servlet Actions are effected through method invocation on the object Multiple concurrent requests are handled by multiple threads on the same object Figure 2 1 Scal
11. TimeZone setTransient transientFlag boolean setType type String ShortConverter Figure 4 7 Fraction from javax faces convert package 38 CHAPTER 4 JAVASERVER FACES convert the Date type to a String and back again If the property is bound to a converter validator or listener instance then the property has to be of the appropriate converter validator or listener type Managed Beans which are a declarative method of creating backing beans and model objects release the developer from the task of creating backing beans manually A backing bean that is declared in the configuration file as a managed bean is made to be available to the application throughout the application life cycle The backing beans are stored in the scope according to the specification in the configuration file Chapter 5 JavaPersistence Java Persistence API is a new API providing object relational mapping for accessing relational databases by Java EE 5 applications Last chapter discussed about JSF one possibility how to create dynamic web content with higher level of abstraction Although web development advances from pure scripting for the generation of dynamic content to a more object oriented approach the underlying data sources are still at most relational databases As a result moving the presentation layer to an object oriented approach results in a mismatch between the relational model of the databases and t
12. acquainted with the problems in an appropriate way I was expected to apply and demonstrate such theoretical knowledge implementing of one specific web application for support teaching of computer s acquirements the Virtual Center for Educators of Seniors Anotace Tato diplomov pr ce se zabyv problematikou tvorby podnikovych serverovych webovych aplikac v jazyce Java C lem bylo nastudovat materi ly kter s danou problematikou zce souvis a podat je tak abych ten e vhodnou formou uvedl do problematiky Nasb ran teoretick znalosti jsem pot m l aplikovat a demonstrovat t m jejich vyu it p i implementaci specifick webov aplikace pro podporu v uky po ta ov ch dovednost Virtu ln ho centra pro vzd lavatele senior Keywords JavaTM EE 5 Java EE Application Model SJSAS 9 Glassfish Java Servlet JSP JavaBeans JSF API MVC JAAS JTA UI Components Java Persistence API Security NetBeans IDE MySQL Virtual Center xi Contents List of Figures List of Tables I Theoretical Background Java EE 5 1 Java EE overview 1 1 Enterprise Application lt lt ses 1 2 Application Architecture lt lt lt lt 244 1 2 1 Model View Controller lt lt lt lt 222A Lb2l Modell orii eek 22 22 Be 2 ae Mi Dee 1212 Model e coc san Speke E A EUR ee 1 3 Java EE Components s sss ik er Brei L4 Java Eb Containets mm aan Deere derer WIRE wg ne e 1 5 Java APS on
13. passwd VARCHAR 80 3 ve tutoral FKIndex1 voting BOOL role of the user email VARCHAR 60 author of tutorial userid user manage BOOL o year of birth INTEGER Io 3 ve tutorial Fkindex3 name VARCHAR 45 gender VARCHAR 6 branch id description VARCHAR 255 locality VARCHAR 128 Y skypename VARCHAR 45 icq VARCHAR 20 9 avatar filepath VARCHAR 60 B P sw_id INTEGER FK author of sw vote suspended BOOL jceeaming vj 9 user id INTEGER FK approved BOOL J elearning id INTEGER rate SMALLINT gt lastiogin DATETIME author of elearning branch id INTEGER FK create datetime DATETIME a create datetime DATETIME m user id INTEGER FK a vesn vote Fkindext 00 userprofile BLOB name VARCHAR 45 Y userid M Q wsersettings BLOB 4 description VARCHAR 4096 a esn vote_FKindex2 3 ve usen FKIndex1 Q Create date DATE E role id vc elearning FKIndexi interested who user id Rel 23 TE wc elearning FKIndex2 P user id INTEGER FK branch td qp branch id INTEGER FK BED A vc Janguage knowledge details VARCHAR 255 9 language id INTEGER FK 3 vc user has vc branch FKIndexi P user_id INTEGER FK discuss about sw Y userid 3 ve user has language FKindext r author of sw veuser_has_ve_branch_Fkindex2 userid ER Q branch id 3 ve language knowledge_FKIndex2 p ji language_id branch of the tutorial branch of the
14. FR title VARCHAR 256 2 E ceste date DATE body VARCHAR 4096 du ES title VARCHAR 255 DT discuss about news p vc tut vote FKIndex2 body VARCHAR 4096 lt 3 ve disais Finder Q tutora ja vc nens FKIndexl tutorial id author of tut vote 7 E userid aj ve discuss FKIndex2 news id a ve discuss FKindex parent id 3o B vc discuss FKIndex4 vote of tutorial author of the news user id ja caes Amas discuss about tutorial Y swid T Y Tum portal messages id INTEGER a ial id INTEGER Q userid INTEGER FK author_of message o INTEGER FK title VARCHAR 255 l user_id INTEGER FK body VARCHAR 4096 ro create date DATE create datetime DATETIME title VARCHAR 255 a portal messages FkIndext O description VARCHAR 255 user_id users_feedback filepath VARCHAR 255 S ees Q Visited counter INTEGER ve user width INTEGER A userid NTEGER SSS height INTEGER ve user role id INTEGER FK timelength VARCHAR 32 qp role id INTEGER firstname VARCHAR 45 suspended BOOL admin BOOL G9 surname VARCHAR 45 pp demonstrator name VARCHAR 60 tutorial BOOL username VARCHAR 45 demonstrator details VARCHAR 255 discuss BOOL PD
15. Java Servlets Enterprise JavaBeans and the other components known in older versions In Java EE 5 is new support for JavaServer Faces server side user interface component framework for Java technology based web applications and new API for programming accessibility between Java components and remote data storages This API new in Java EE has been called Java Persistence discussed in chapter 2 discussed in chapter 3 discussed in chapter 4 discussed in chapter 5 6 CHAPTER 1 JAVA EE OVERVIEW Some XML descriptors are now with Java EE 5 optional Instead a developer can simply enter the information as an annotation Figure 1 1 directly into a Java source file and the Java EE server will configure the component at deployment and run time Java EE enable using the same application on different systems without any modification of source code Java EE ensures for their components a lot of services which are provided automatically such as component life cycle management or transaction life cycle management 1 1 Enterprise Application The term Enterprise Application is used to describe business related applications that consist of a server and client part also referred to as client server application 11 As the client part of the enterprise application has to be connected to the application server using a proper com munication infrastructure According to 13 an enterprise application has generally following characteris
16. Pool from the main frame Name mysqlPool Resource Type javax sql DataSource Database Vendor mysql Next Fill the form Transaction Isolation read uncommitted Check Isolation Level Guaranteed Delete all predefined properties 12 2 VALIDATION TEST 95 8 Add following properties serverName localhost poolNumber 3306 Password toor User root databaseName vc e Create new JDBC Resources 1 2 3 In Admin Console left tree menu choose Application Server gt Resources gt JDBC gt JDBC Resources Press New button Fill the form JNDI Name jdbc dataSource Pool Name mysqlPool Enabled checked e Deploy the Virtual Center application 1 ie From left tree menu choose Application Server gt Applications gt Web Appli cations Press Deploy button Choose the file vc dist vc war from enclosed CDROM Next Check Precompile enabled Logout Admin Console Start the Virtual Center Start your favourite web browser 2 type url https localhost 8181 vc faces index jsp e Additional information According to vc web database loadscript sql the Virtual Center knows following users username jarda kortus password heslo user role admin username martin kortus password mheslo user role registered username helenka holikova password hheslo user role vip This tutorial is available in dynamical shockwave flash form in demo demos html folde
17. Usually there is no central place to configure the flow between the views of a web application Almost every view has to define the possible paths itself In a large web application with hundreds of pages it is almost impossible for the developer to keep up with all possible transitions between the views Maintaining of such web application and its page flow is a challenge JSF provide a navigation system that simplifies the complexity and increases the main tainability of web application s page flow The main part of this navigation system is the navigation handler represented through a single instance of the NavigationHandler class The handler is invoked as a result of action events fired by UIComponents that handle user in teraction These UlComponents are associated with methods on the JavaBeans in the backend They execute application logic and return an a proper outcome to the result of the processing done by the business logic dynamic navigation or return a hardcoded outcome static navi gation According to this outcome and the navigation rules defined in the JSF configuration file faces config xml the next view is selected Navigation rules define the possible navi gation paths In other words they define which view can be navigated from another view or a set of views according to outcomes of executed methods in the business logic 4 4 6 Events and Listener Model Event driven design is very common for SWING applications but for
18. a js ba R tab ee D FIDE ume enisi 6 3 1 Realm User Group esse er ene o NUR TOR dA SUR ukon diee 6 4 Secure Connection Using SSL lt lt lt lt CE En nn 6 4 1 Java EE application with SSL 2 2 2 CE Emm nn 6 5 Specifying a Security Constraint 6 5 1 Specifying a authorized users lt lt lt lt 4 lt 6 5 2 Resource constraint in Java EE Application Virtual Center for Educators of Seniors Introduction 151 Skeleton plam cans xe at A AAA ly e db vaha a Basic Study 8 1 User Profiling of the Virtual Center lt lt lt lt lt lt lt 0 00000 0000 25 25 25 26 28 29 29 30 30 32 32 32 34 36 36 39 39 40 40 40 41 42 44 45 45 46 46 47 47 48 49 49 50 51 53 53 55 8 2 8 3 8 4 8 5 8 1 1 Support for multimedia nn 8 1 2 Application Stability o o e 8 1 3 Security requirements Comm 8 1 4 Internationalization and Localization 2 2 2 m onen Setting specific goals lt lt lt lt lt lt lt lt rn Use Case ze a jE xd a ee a abe Chosen use cases in higher detail 2 2 lt lt lt lt lt nn Usability bounds setting lt lt lt lt lt lt 4 on lees 9 Analysis 9 1 9 2 9 3 9 4 Concurrent systems Data analysis ten F je EL ER Technology frameworks lt lt lt lt lt lt nn 9 3 1 Frameworks airada da ole Mady a a Eom e a oh di
19. appropriate components in the view The 4 3 THE LIFE CYCLE OF A JSF PAGE 27 No input data first run Render response e Request income gt Restore view phase Process events Apply request values Invoke application Y Conversion error Process events su Conversion erro Process events p y A V Process validation Update model value X Render Response gt Process events renderResponse method called Figure 4 2 Statechart diagram of request processing life cycle view is stored in FacesServlet If the request is initial first request for a page no request data are available and so another phases are skipped up to render response phase Phase 6 Empty view is populated If the request is not initial view corresponding to this page must exist and it is also accessed Phase 2 Apply Request Values In apply values phase every component from current view is accessed and called on decode If any decode methods or event listeners called renderResponse method on the cur rent FacesContext instance the JSF implementation skips to the render response phase Phase 6 Input data are converted and stored on components If data conversion cause er ror an error message is generated and queued on FacesContext If event is queued in this phase JSF broadcast interested listeners If the application n
20. components RowSet Whether or not DataProvider is used however the CachedRowSet has to be cre ated Keep in mind that if a database table is dropped on to a page the Netbeans au tomatically creates a CachedRowSetXImpl in the SessionBeanl by default and a CachedRowSetDataProvider in the page itself code behind for that table It is the CachedRowSetXImpl s command property that is the SELECT statement that provides the key to the database INSERT operation The table INSERT command generated by the IDE includes all the columns that are in the CachedRowSetXImpl s command property For example suppose the RowSet s com mand property is SELECT ALL elearning id branch id user id name description FROM vc_elearning The INSERT command for this RowSet then becomes INSERT INTO mytable elearning id branch id user id name description VALUES Code example on Figure 11 1 illustrates DataProvider methods how can be simple used for inserting a row into a data source Firstly the canAppendRow method followed by appendRow method are used and if it is possible to append row then an empty row is appended as result to the CachedRowSetDataProvider Then call setCursorRow to set the DataProvider s cursor to the new row s location The same setValue method is used to set the different column values regardless of the column types Finally commitChanges method is called to committing the changes to
21. conference or community webs try to imitate real discussion between people in digital form Seniors as well as the educators of seniors are special group of users which prefer eye to eye contact to written form First requirement is also to design any mechanism providing spoken form of communication Similarly I have to find any possibility how to share best practices and other study material over spoken form For spoken communication between two or multiple members of community exist number of possibilities Very good experiences I have with Skype software which enables to communi cate with classic phone numbers all over the world too but above all it is free for use in domain and has very good support The calling to another skype user is absolutely free of charge For all that Skype technology has own weaknesses but this is about another story Another pos sibility should be another type of VoIP technology but devices for using this technology are very heterogeneous and control is not always trivial In addition no another technology has up to date support comparable with skype 8 1 2 Application Stability In case the application will be used for creating e community on a professional level it is very important the stability of the system Application must be tested and developed on the same system on that will be then running Not only performance of Application and database server but functionality are very important to achieve stable
22. da a De dae 3 10 JavaServer Pages Standard Tag Library lt lt 4 42 JavaServer Faces 4 1 What is JavaServer Faces lt lt 2 eee 4 2 The MVC architecture of JSF 2 22A 4 3 The Life cycle of a JSF Page lt lt lt lt lt lt lt lt 4 3 1 JSF life cycle scenarios lt lt lt lt lt 444 4 4 JSF development process lt lt lt 2s 4 4 1 UI Components and the Component Tree 442 PacesContext uu uode ee Ban ia a 4 4 3 Package javax faces Tender nenn 4 4 4 Messages i77 ene E A a 445 Navigation 22 2 222 808 2 2 AA A AA 4e 4 4 6 Events and Listener Model ls 44 7 Validation Model sucias Duke piel ka bo SEX d xxu 44 8 Converters wars pda e b Rebate Pina cu se bah oss 4 4 9 Backing beans i 9o Daran nn SURG k S X OR ES bk JavaPersistence 5 1 Java Persistence API zus zw Row Rep EX gne d wg I e Dle EAS dioec REDE oer ferus ee ores ig ento La erg oa ede tos 5 1 1 1 Relationship multiplicities lt lt 4444 5 1 1 2 Entity Life cycle and Entity Listeners 5 1 2 Entity Management lt lt 44 5 1 3 Persistence in the Java EE application lt lt 5 1 4 Persistence in NetBeans lt lt lt lt Java EE Security 6 1 xPhysical Security tas A Bei ete e Poe Ted an eg 6 2 Operating system security lt lt lt lt lt lt 4 4 eee 6 3 Applicati n security se soer medem a
23. elearning jw gt Rel 26 P Sswid INTEGER Q userid INTEGER FK interested in vc language description VARCHAR 255 7 language_id INTEGER c create_date DATE name VARCHAR 45 download counter INTEGER filepath VARCHAR 128 4 B um Fade branch of sw userid penaa od parent id INTEGER FK Ho 2 B vc sw FKIndex2 0 name VARCHAR AS parenting_in_branch description VARCHAR 255 08 LG ve branch_FKIndex1 parent id Figure 10 1 ER model 10 2 COMPONENT DESIGN 73 Glassfish server 9 01 Sun Java System Application Server is an opensource server side utility known as Glassfish listening on specified port and providing servlet container service among others web xml Deployment Descriptor file configuring the virtual center application Servlet Every JSP page is compiled into the servlet class according to the JSP life cycle page 19 JavaBeans JavaBean objects are divided into four types according to scopes which they be long to Depending on which scope the JavaBean belongs Glassfish manages its life cycle JavaBeans are configured by the managed beans xml descriptor file JSF recognizes four types of scopes Application Session Page Request The only Application JavaBean could be shared by multiple relations CachedRowSet In a nutshell A CachedRowSet object is a container for rows of data that caches its rows in memory and makes possible to operate
24. following fundamentals e Limited services The services offered by the computer running the web server should be kept to a minimum This minimizes the threats to the web server since each network service carries its own risks By eliminating all nonessential services you eliminate poten tial holes through which an attacker could break into your system Examples of services which may pose un needed risks include mail FTP file sharing remote access etc e Most privileged user The number of users with most privileged access e g root in UNIX or Administrator in NT should be kept to a minimum The most privileged users must never use cleartext re usable passwords for remote authentication since passwords can easily be sniffed over public networks e Limited number of account The number of user accounts on the system should be kept to a minimum This minimizes threats because it limits the number of accounts capable of attempting to elevate privileges without authorization e Authentication If weak authentication i e re usable cleartext passwords is to be used for unprivileged accounts then user passwords must be at least seven characters long must not be dictionary words must contain a mix of alphabetic numeric and special characters and must change at least every sixty days Good password security is the first line of defense against system abuse Intruders will often try to guess passwords or will try to crack them aft
25. gt CUS repository folder Masters thesis document LaTeX sources inc images gt Other sources UML DB scheme Print version of the thesis Netbeans vc project folder Netbeans Build directory the Virtual contas Ueb ARchive file JavaDoc folder vith libraries Connection Poci configuration foe the UCO Source files JUnit tests folder Netbeans vc_JPA project folder Figure C 1 The list of enclosed CDROM 113 114 APPENDIX C CONTENT OF CD Bibliography 10 11 12 13 14 15 16 17 18 Mary Campione The JavaTM Tutorial Addison Wesley 2000 Pavel Herout U ebnice jazyka JavaTM KOPP 2003 ISBN 80 7232 115 3 Pavel Herout Java Bohatstv knihoven KOPP 2003 ISBN 80 7232 xxx x Dave Ragget Le Hors lan Jacobs HTML 4 01 http www w3 org TR htm1401 Dusan Janovsk Jak ps t web http www jakpsatweb cz Web Developer http www webdeveloper com html B Mannov K Vos tka zen softwarov ch projekt Nakladatelstv VUT 2005 Praha ISBN 80 01 03297 3 Danny Coward Java Servlet Specification Sun Microsystems 2006 Group of authors XML Tutorial http www w3schools com xml default asp Ji Kosek XML pro ka d ho Grada Publishing 2000 ISBN 80 7169 860 1 nttp www kosek cz xml xmlprokazdeho pdf R Orfali Essential Client Server Survival Guide Second Edition John Wiley amp Sons 1997 Java Community Process JavaTM
26. http method gt PUT lt http method gt 45 lt http method gt OPTIONS lt http method gt 46 lt http method gt TRACE lt http method gt 47 lt http method gt DELETE lt http method gt 48 lt web resource collection gt 49 lt auth constralnt gt 50 lt description gt 51 lt role name gt helloUser lt role name gt 52 lt auth constraint gt 53 lt user data constraint gt 54 lt description gt 23 lt transport guarantee gt CONFIDENTIAL lt transport guarantee gt 56 lt user data constraint gt 57 lt security constraint gt 58 lt security role gt 59 lt description gt 60 lt role name gt helloUser lt role name gt 61 lt security role gt Figure 6 2 security constraint element in DD Security role element on lines 58 61 in Figure 6 2 specify which users are known for my web application In this case it is helloUser This type of user needn t to correspond with user groups defined in Application Server For mapping security roles to Application Server principals and groups can be used security role mapping element in the runtime DD sun web xml Auth constraint element on lines 49 52 specify which type of user has to be authen ticated for this web resource Web resource collection element on lines 36 48 specifies the protected web re source my own name for this resource and type of requests which are filtered by this con straint User data constraint on lines 53 56 specify that data will be tran
27. jstl 1 1 docs tlddocs py un Oracle About the Model 2 Versus Model 1 Architecture http www oracle com webapps online help jdeveloper Hans Bergsten JavaServer Faces Building Web Based User Interfaces O Reilly 2004 NetBeans home site http www netbeans org Unified Modeling Language home site http www uml org J Arlow I Neustadt UML a unifikovany proces v voje aplikac CP Books 2005 Brno ISBN 80 7226 947 X Sun Microsystems Inc Singapore 2006 Tech Days http developers sun com events techdays presentations singapore2006 NetBeans team Java Persistence in the Java EE 5 Platform http www netbeans org kb 55 persistence html Sun Microsystems Inc Sun Java System Application Server Platform Edition 9 Admin istration Guide http docs sun com app docs doc 819 3658 Sun Microsystems Inc J2EE 1 4 Security http java sun com j2ee 1 4 docs tutorial doc Security3 html Information on SSL specification http wp netscaspe com eng security Java Community Process Common Annotations for the Java Platform Sun Microsystems Inc Application Deployment Guide for the Application Server http docs sun com doc 819 3660 Public comunity Top XML tutorials blogs and forums http www topxml com Frank Kelly My thoughts on best practices in software architecture and development as a whole http softarc blogspot com
28. limited on covering the quality of the code Pm not engaged in problematics of analysis or design of application here 10 4 2 Testing strategy 1 Unit tests these tests are focused on application module verification like JavaBeans codes behind classes According to description of the methods there are most im portant routes in module are tested here Single parts of unit tests are white box as well as black box testing For unit testing will be used JUnit module in Netbeans which is able to generate some elementary unit tests actually by itself 2 Integration tests integration up to down The beginning is on the main module and the progress leads down e g Breadth First Search The main module is driver stubs substitute all the subordinated modules In time stubs are replaced by real modules See Alzasoft http www alza cz or OxyOnLine http www oxyonline cz Approximately two years I m regular reader and contributor in the nbuser community and I know that every day are discovered several new issues and bugs in Netbeans IDE although they have 25 quallity engineers in the team 10 5 ACCEPTANCE TEST 81 When new module is integrated the system is tested again synonym for such testing ls regress testing 3 Regress testing checks if an error occurs when new module is added Previous tests are reprocessed The error detected by this tests has to be called displaced error 4 Validation testing
29. necessary operation resulting from init or doMethod method of servlet s object 2 3 Filtering Request and Responses The Java Servlet specification version 2 3 introduced a new component type called filters A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses Filters typically do not themselves create responses but instead provide universal functions that can be attached to any type of Java Servlet or JSP Page 19 There are the most frequently objectives which are servlet s filters user for e Blocking the request response pair from passing any further e Modify the request response headers and data object format customization e Interact with external resources e Blocking request from passing authentication based filter e Image conversion into supported format e Data compression makes downloads smaller 14 CHAPTER 2 JAVA SERVLETS e Localization according to user s localization e Reformating to another document format Filter is Java EE class which implements javax servlet Filter interface Because servlet filters are attached from numbers of users some inconsistences within the application might become It is also very important to synchronize methods within filter classes After all the developer mustn t forget to specify filter mapping rules in application s DD 2 3 1 Creating of filter classes Most important method i
30. output OK Suspended user can t login now System message about suspending of the user is caught Error Suspended user logged successfully Suspending operation has not be per formed although an successful message was caught Suggestion problem in method enganged with suspending the user Error System message about A DataProviderException thrown is caught Con nection cannot be established User wasn t suspended Table 10 2 User suspending Action User unsuspending Description Admin users can unsuspend any suspended user Valid unsuspended user account can be suspend again Only privileged users with admin or user management rights are able to perform this functionality Requirements identical with Table 10 2 except for suspended instead of unsuspended Progress identical with Table 10 2 except for unsuspend instead of suspend Possible output OK Unsuspended user successfully logged again Error Unsuspended user can t login successfully although a system message about user unsuspended was caught Suspending operation wasn t performed Sugges tion an error should be within the method enganged with user unsuspending Error System message about A DataProviderException thrown is caught Con nection cannot be established Unsuspend action wasn t performed Admin can try to repeat the action Table 10 3 User unsuspending Ac
31. phones or other non PC devices although some of technologies described in Part I make it possible Because of data flow volume in Virtual Center such feature is not found desired today but regarding to increasing support for Skype and other data technologies such feature could be released sometime in the future Chapter 9 Analysis 9 1 Concurrent systems Like the TeachUComp also Virtual Center will provide a collection of the most essential skills every user should know but free of change for registered users In addition Virtual Center builds a virtual community of educators and students within members will help each other when some problem occurs Because the application sketch is very solitary it is necessary to inspire with other sys tems well known for many users Such system could be e g e shops that provide wares shop ping Virtual Center will be also offering to something but tutorials instead of wares The price for wares in virtual center case is free 9 2 Data analysis Regarding to preceding chapter and to working knowledge new data model and data analysis will be designed Because of possible problems resulting from redesigning of data scheme in the future database scheme will contain also some tables and structures which will not to be implemented eg vc_elearning vc_news vc_portal_messages in first release of Virtual Center Such data will not be in question within this section or chapter but appear in s
32. the entity is loaded from the database 5 1 2 Entity Management To manage the interaction of entities with the Java Persistence facility applications use the EntityManager interface This interface provides methods that perform common database functions as querying and updating the database The set of entities that can be managed by an entity manager are defined in a persistence unit The persisting unit is defined and configured by persistence xml An application that uses the JPA does not need to explicitly create a connection to the data source as it would when using JDBC technology exclusively The only condition which has to be performed for using database connection by JPA is created DataSource object in the Application Server In the next section IIl try to demonstrate how to work with Java Persistence without any advanced tools to make better sense of Java Persistence setting and working with TJDBC Java Database Connectivity API is the industry standard for database independent connectivity between the Java programming language and a wide range of databases SQL databases and other tabular data sources such as spreadsheets or flat files When using NetBeans IDE combined with Sun Java Application Server DataSource is configured automat ically by deploying project phase 42 CHAPTER 5 JAVAPERSISTENCE 5 1 3 Persistence in the Java EE application For simplicity I ll presume that I have installed MySQL server where
33. the data source A simple catch statement is needed to catch some errors that might occur Instead of appending a row the CachedRowSetDataProvider insertRow method can be used to insert a new row before a specified row If so it is necessary to know the RowKey value for the row before that the new row should be inserted and to pass that value as a parameter to the insertRow method 11 1 SELF IMPLEMENTATION 89 public String createElearning try if elearningDP canAppendRow true SimpleDateFormat sdf new SimpleDateFormat yyyy MM dd Date now new Date System currentTimeMillis nd row if possible RowKey appendRow elearningDP appendRow elearningDP setCursorRow appendRow set the new data values elearningDP setValue vc_elearning branch_id id elearningDP setValue vc elearning user id getUserProfile getUser id elearningDP setValue vc elearning name newItem 0 nameField getTex elearningDP setValue vc elearning description newItem 1 elearningDP setValue vc elearning create date sdf format now elearningDP commitChanges elearningDP refresh info new tutorial added return hello else error can t add vc elearning row return null catch DataProviderException ex log cannot add new elearning because of dataProviderException thrown ex printStackTrace info cannot add new elearning course DataProviderException retu
34. to store data from database Decision Support Check Enab Selected Default Instal Run app mysql essential 5 0 24a win32 msi from enclosed CDROM tabase le TCP IP and Strict Mode Choose the port 3306 t Character Set utf8 ll As Service and Include bin directory in PATH both Set password toor for the root user don t create anonymous account Execute 93 Notice that this 94 CHAPTER 12 TESTING AND INSTALLATION e Install MySQL GUI Tools 1 2 Run app mysql gui tools 5 0 r3 win32 msi from enclosed CDROM Follow the installation wizard e Restart computer when needed e Start MySQL server service e Start Sun Java System Application Server 9 e Run Query Browser from MySQL gui tools e Create new database 1 2 Fill the form Server host localhost Port 3306 Username root Password toor Default schema vc Confirm that you want to create new schema vc e Create data scheme 1 2 3 File Open Script Choose vc web database createscript sql from enclosed CDROM Execute e Insert example data into database 1 2 3 File Open Script Choose vc web database loadscript sql from enclosed CDROM Execute e Create new Connection Pool in the Application Server 1 Run Start Sun Microsystems Admin Console 2 Login with admin username and your admin password 3 4 Fill the form Choose Create new JDBC Connection
35. too Now I ll make a short overview about the context according to partioning of the thesis into chapters e Part 1 Theoretical Background Eight chapters will describe Java EE technology and basic principles used in conjunction with Java EE application development process Not only about Java EE components but other useful opensource software tools such as UML modeler database designer I ll talk too Chapter 1 Java EE overview describes what is Java EE Application how looks its architecture like what is composed from and what about main features are in Java EE version 5 technology Chapter 2 Java Servlets describes Java Servlet technology used components how looks Java Servlet life cycle what are listeners and filters and what are the most powerful features of Java Servlets Chapter 3 JavaServer Pages Technology describes JSP JavaServer Pages their life cycle what are JSP pages composed from or how to use external resources such as JavaBeans components in JavaServer Pages Chapter 4 JavaServer Faces gives an overview about JSF JavaServer Faces technology with revolutionary JSF life cycle The JSF technology chapter takes the biggest fraction of the theoretical background part of this thesis Chapter 5 Java Persistence presents Java Persistence technology and especially the part about JPA Java Persistence API Chapter 6 Java EE Security discusses all the aspects of Java Security and security of web appli
36. up to date the most featured IDE for web development Another environments usable for creating Java EE application are for example Borland JBuilder or Eclipse By the work on Virtual center I used Netbeans 5 5 final release with enterprise pack visual web pack and some of separate modules like Version controll or Sun Java System Application Server support amp NetBeans DE Netbeans IDE 5 5 beta Java EE in Netbeans Netbeans 5 5 supports the Java EE 5 platform and most notably the EJB 3 and JAX WS 2 0 specifications The Java Persistence is not in version 5 5 fully supported especially in Visual homepage http myfaces apache org homepage https blueprints dev java net Commercial IDE for professional development Some of developers do not a thing without JBuilder IDE but in my opinion Eclipse or Netbeans are at least comparable and beyond absolutely free Homepage of Borland JBuilder is http www borland com us products jbuilder index html May be the most popular environment for creating Java application at the moment Biggest drawback and advantage together in Eclipse is the fact that whatever developer wants to do he needs some plug in for it that costs very much time spend on browsing over numbers of interested web pages Home page of Eclipse project is http www eclipse org Eclipse is as well as Netbeans Open Source project 66 CHAPTER 9 ANALYSIS Web pack what has to be the gist why is Java P
37. 11 1 1 Some Netbeans conventions in Java EE development 11 1 2 Login logout and data security lt lt lt llle V ISSUES a A A een ae ee lo es 11 2 Unit tests designing and processing lt lt lt lt lt 44 nn 63 63 63 64 65 65 65 66 67 67 67 68 68 68 68 69 71 71 71 73 74 78 79 79 80 80 80 80 81 81 82 82 82 12 Testing and installation 93 12 1 Installation manual ko ho Ro ee eR a UR RR 93 12 2 Vahlidatiotr test ata ipe a aaU Ais E qux eR 95 III Conclusion 97 13 Conclusion 99 A Database report 103 B Screenshots 107 C Content of CD 113 Bibliography 115 List of Figures 1 1 XML annotations in source code lt lt lt 4 4 4 ee 5 1 2 Multi tiered Application lt lt lt lt lt lt 4444 7 1 3 Model 1 architecture of Java EE applications 8 1 4 Model 2 architecture of Java EE applications 8 L5 Java EE Platform APIS 9 euge gg ae 2 pran ER 10 2 1 CGI script vs Java Servlet life cycle lt lt lt ee ee 11 2 2 Semantics for inserting listener into DD Deployment Descriptor 12 2 3 Filter to Servlet Mapping ss 14 2 4 Filter to Servlet Mapping Deployment Descriptor 15 2 5 Filter for all the Servlets lt lt lt lt lt lt lt 000002 eee eee 17 3 1 Gonstruction of JSP 2 2 0 ia k debeo A enu EU RUPEE E Ds 20 3 2 Root element in JSP XML complian
38. 9 32 Tools z 214 3 as a rauschen 93 21 Netbeans DB i r zu na ea rer en 93 22 GVSNT Server oue ee ee ue deg darse Ba 9 3 2 9 Star ME ser a pod how Er Dress 9 3 2 4 DBDesigner lt 2 22 nommen 9 3 2 5 Ereemund 2 24 66 Rec ndash re 9 3 2 6 Inkscape ura ie Rep ure odk S 9 3 2 7 Gimp s mao an aa Dale SeEVGE environment x uz A DE St EXE 9 4 1 Java Sun Application Server lt lt lt lt 4 ee 9 42 MySQL of bolo A e Maa AS A Mer iet cte 10 Design 10 1 Databasedesien x 4 Je 2 4 0 0 2 de e doe ad dia Rate pim ee 10 2 Component design rg 22 en Hr oe Kul So A RR Ruhe sed 10 21 Pagesstructule ug ab ee a wee ee ren 10 2 2 Pages description oier mor eg Ge Ble hc Rhee e Kup MARK Paes 10 3 Graphical user interface lt lt lt lt lt on 10 3 1 Pageframing ss 10 3 22 9101872 IS iet oor udo oue aed NE cA cp UBL ood dedi 22 10 3 3 Orderins og 2m en eR grossen We ad cue med Yr Ere ed ios 104 Testing 20mm XXe AAA A A ee Bae 10 4 1 Generally about test processing lt lt lt lt lt 44 4 4 lt lt 10 4 2 Testing strategy lt lt lt lt eA 10 4 2 1 Test reports 10 5 Acceptance DES y A ae A A un 10 5 1 Conditions of acceptance tests lt lt lt 4 lt nn 10 5 2 Documentation requirements 22 2 lt lt lt 4 000004 10 5 3 Functionality requirements ss 11 Implementation 11 1 Self implementation ui 220 ee ar ir a Eee
39. Action Create new discuss thread Action Remove discuss thread Action Reply existing discuss Action Add user tutorial to the favourites Action Remove user to the favourites button hyperlink Action Remove tutorial to the favourites button hyperlink Action Call user with skype Action Email to the user Action Find tutorial by id Action Find discuss by id Action Add registration request Action Navigate tutorial from the list of favourites Action Navigate user from the list of favourites Table 10 13 Addional tested functionalities Chapter 11 Implementation In consideration of possible improvements of Virtual Center in the future I choose Java EE technology because in my sketchy analysis of two strongest technologies NET and Java Java turned out to be a better choice Just at the moment Java offers in my opinion more features better community very good IDE Netbeans with Visual Web Pack and better application architecture In addition there is new application server Sun Java System Application Server 9 resulting from previous versions of commercial Java Application Server up to version 8 and developed as well under opensource project named Glassfish Very good facility of Java EE and Glassfish server is the possibility to debug web appli cations No other technology provides such instrument for web developers Because Java technology is not bound on one concrete database product and because I hav
40. Czech Technical University in Prague Faculty of electrotechnics VUT FEL katedra po ta Master s thesis Virtual Center for Educators of Seniors Jaroslav Kortus Supervisor Ing Bo ena Mannov M Math Study program Electrotechnics and informatics Branch Informatics and computer science 2007 Task Prohl sen Prohla uji e jsem svoji diplomovou pr ci vypracoval samostatn a pou il jsem v hradn pod klady uveden v p ilo en m seznamu Nem m z va n d vod proti u it tohoto d la ve smyslu 60 Z kona 121 2000 Sb o pr vu autorsk m o pr vech souvisej c ch s pr vem autorsk m a o zm n n kter ch z kon autorsk z kon WiPraze dne ne n caci n di oda Ets Acknowledgments I would like to thank to my supervisor Ing Bozena Mannov M Math for the proposition of the topic for the help with formal aspects of the thesis and for guidance through the whole process of writing this thesis Special thank goes to my friend Ing Helena Hol kov for a proof reading Dedicated to my parents Jaroslav and Bozena with gratitude for their endless patience boundless support and love vil Summary This final project deals with the problems addressed by development of enterprise server side web applications in Java programming language I was assigned to study a plenty of materials which are closely related to mentioned branch and hand it over in order to get the reader
41. Java EE 5 has two essential types of clients Application Client An application client runs on a client machine and provides a way for users to handle tasks that require a richer user interface than could be provided by 1 4 JAVA EE CONTAINERS 9 Component location Application component Web component Client machine Applet component TM Java Servlet TM JavaServer Faces Server machine JavaServer Pages JSP technology components Enterprise JavaBeans EJB components Server machine Table 1 1 Java EE components a markup language It means that application client can communicate directly with business tier running on the application server Application clients are known as fat clients Web Client Web client in contrast with application client has two tasks parsing HTML and displaying them All the communication between client and server goes via HTML language Because of web client s limitations compared to application client web clients are known as thin clients Three server side components from the Table 1 1 Java Servlet JSP J SF will be discussed more deeply in separate sections a little bit later 1 4 Java EE Containers Containers are interfaces between components and low level platform specific functionality that supports the component 14 Each container hosts only one or more specific application s com ponents and provides standard and container speci
42. L E success L x RI hello jsp L E completed 5 m E index jsp user jsp tc bane JUNE registr jsp g g i 1 Bdisconnect hello ee lola k 8 S Si user ell 3 2 5 3 elearn jsp ne 5 bad ab disconnect play um ge i f Sdisconnect Si tutorial SHtutorial C u QA Q tutorial jsp L e discuss jsp tnew jsp Figure 10 3 Page navigation diagram 10 2 2 Pages description This section describes behaviors of particular forms pages from previous section and for the most interested of them will be also designed their action diagrams like a template for implementation Forms with elementary behavior or analogous to some another form will not be designed here hello Hello is the start page for basic user where the user is automatically redirected after successfully login for administrators admin page is the starting one Main functionalities of hello page are to present firstly the most important information about state of Virtual Center and secondly 10 2 COMPONENT DESIGN 75 changes since user connected last time Hello page makes all the Virtual Center functionality accessible for logged user depending on user privileges naturally Last but not least the hello page displays personal preferences for actual logged user because the application makes possible some customizations On Fig
43. L for working with XML documents 3 IL8N or Internationalization 4 SQL for working with databases Here is short list about tags defined by JSTL This list doesn t cover every JSTL tag but the most commonly used ones A complete list of the JSTL tags including attributes of them is available in 23 1 Core prefix c e variable support remove set e flow control choose when otherwise forEach forTokens if e URL management import param redirect param url param e Miscellaneous catch out 2 XML prefix x e core out parse set e flow control choose when otherwise forEach if e transformation transform param 3 I18n prefix fmt e setting Locale setLocale requestEncoding e messaging bundle message param setBundle e number and date formatNumber formatDate parseDate parseNumber setTimeZone timeZon 4 Database prefix sql e setDataSource e SQL query dateParam param transaction update dateParam param Chapter 4 JavaServer Faces After discussing about fundamental technologies and related problematics of Java web ap plications development this section focuses on a concrete web application framework JSF JavaServer Faces There are today over unbelievable 20 different web application frameworks and none of these frameworks is based on a standard So high number was definite indication that a standard solution is missing JSF have been chosen for this thesis since it is likely t
44. Servlet Specification Evaluation 2 5 http jcp org aboutJava communityprocess mrel jsr154 index html M Fowler Patterns of Enterprise Application Architecture Addison Wesley 2002 J Ball D Carson I Evans S Fordin K Haase E Jendrock The Java EE 5 Tutorial http java sun com javaee 5 docs tutorial doc Sun Microsystems 2006 Update 1 Sun Microsystems Inc JavaServer Pages 2 0 http java sun com products jsp download html specs Group of authors Wikipedia Java Servlet http en wikipedia org wiki Servlet Web accessible document J Hunter W Crawfor Java Servlet Programming O Reilly 1998 Julie Leung Jeremy Dawson Servlets on Software Engineering Research Network http sern ucalgary ca Courses CPSC 547 W2000 webnotes Servlets 115 116 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 BIBLIOGRAPHY Sun Microsystems Inc Essentials of Filters http java sun com products servlet Filters html Internet Assigned Numbers Authority home page MIME Media Types ttp www iana org assignments media types Sun Microsystems Inc Java Servlet web site http java sun com products servlet un Microsystems Inc The JavaServer Pages web site ttp java sun com products jsp py WN un Microsystems Inc JavaServer Pages Standard Tag Library 1 1 Tag Reference ttp java sun com products jsp
45. Y an ald 53 getResultList 54 catch Exception ex 55 throw new BooksNotFoundException 56 Could not get books ex getMessage 57 58 Figure 5 5 Simple query on animal table 44 CHAPTER 5 JAVAPERSISTENCE Simple query on Figure 5 5 will extract from animal table all records ordered by value of ID Resulted list will be returned as List of records For changing value in database we have to use a appropriate setter because aName parameter is defined with private access right method in Animal class and change param eter For example with an setAName String newName can be changed a Name of the animal UserTransaction resource To ensure that the update is processed in its entirety the call to changeName method that calls setAName method can be wrapped in a single transaction Following code is a example of using UserTransaction interface by Resource annotation Resource UserTransaction utx ery A utx begin animalDBAO changeName animalName newName utx commit catch Exception e try utx rollback catch Exception e System err println Rollback failed Figure 5 6 Using JTA transaction manager 5 1 4 Persistence in NetBeans NetBeans from 5 5 has special templates for creating Entity classes directly from database Developer chooses only data source and selects for which database tables want to create entities Then must insert persistence
46. a discussion of the proposed concepts and achieved results The main goals of the thesis were study of Java EE application architecture model together with modern Java EE development process and implementation of the server side application for improving education of seniors The first part of this whole thesis is enganged in single steps and principles of Java EE development process Foremost the Java EE technology and application architecture are described In the middle of the thesis there is one chapter about Java Persistence API Java Per sistence API is not entirely supported by development tools and user interface components at the time and that was the main reason why I have finally decided to use another technology Chapter 11 1 1 about CachedRowSets starts on page 87 for Virtual Center s database han dling Java Persistence API is a new feature in Java EE version 5 therefore this chapter stayed in the thesis although another technology was choosed for the database handling of the Virtual Center application The power of object relational mapping is shown on web application for table man amement of my Virtual Center s database In demos demos index html there is a short demostration of vc_JPA application developed wholly by Java Persistence API in Netbeans Vc_JPA application is no UI Component using simple web application for database table man agement used during the development of Virtual Center The Java EE is a quite large f
47. ability As a result of the previous Java servlets are highly scalable Additionally the fact that there is only one servlet instance regardless of the number of requests means that a servlet can keep track of state information between multiple requests by using the Session Tracking API Integration Java Servlets are tightly coupled with the server A Servlet can use the server to perform duties such as translating file paths A servlet uses a ServletContext object to access server functionality Some believe that servlet interaction with the server is less error prone than performing the same actions using server specific extensions Sometimes an error handling page may be able to do something more graceful than show an error perhaps choosing instead to show an online help chat window to help the user resolve the problem P TnputStreams OutputStreams String Arrays Threads 18 CHAPTER 2 JAVA SERVLETS Chapter 3 JavaServer Pages Technology Servlets make possible to create dynamic content but by designing the static parts it s necessary to use Java language form For more extensive content it could be very unpractical and not providing an easy survey Thanks to JSP JavaServer Pages developer can write some parts in static form and the dynamic part in Java programming language This is very effective technique for writing page s web content with dynamic portions 3 1 JSP s Life cycle JSP is before usage conver
48. able 3 1 is possible to control various JSP page execution parameters To influence structure of generated Remember that Servlet classes had init method to do that 2 According to service method by Servlets 19 20 DIRECTIVES KL CHAPTER 3 JAVASERVER PAGES TECHNOLOGY SCRIPTING ELEMENTS Expressions COMMENTARIES K l KL page Secret Standard include Scriptlets Output Custom taglib Declarations Figure 3 1 Construction of JSP directive attribute possible values page directive lt page language Java extends package class import package class package x session true false buffer none 8kb sizekb autoFlush true false isThreadSafe true false into text errorPage relative URL contentType mimeType charset characterSet text html charset 150 8859 1 isErrorPage true false pageEncoding characterSet ISO 8859 1 gt taglib directive lt taglib uri URIForLibrary prefix tagPrefix 1 gt include directive lt include file relativeURL gt Table 3 1 Syntax of JSP directives Servlet are used directives page By page directive developer can setup which classes Servlet extends or which libraries should Servlet imports This directive is often used for setting error page too Directive include serves inserting other files into JSP pag
49. and multimedia elements for creating some closed community as well as for getting know how in seniors teaching sphere At first I resume the specific application requirements discussed and described in preceding section community Group of people with a unity of interest in education or teaching of seniors Every member will have assign any specific user role according to application privileges conference Virtual center will represent an instrument for exchange experiences in written or spoken form Spoken communication will be provided via free Skype client application whereas for written form will be created embedded discuss tutorials Virtual center will facilitate to share own created tutorials all over the community Such tutorials will be in written spoken or digital movie form Tutorials will be ordered by branches into the well arranged list or tree 58 CHAPTER 8 BASIC STUDY security Maybe in the future Virtual Center will contain some private or sensitive data Applica tion has to be also designed with an advanced security level support User adding and deleting will be provided by hi privileged user or administrator 7 Skype omunity Conference teaching Sharing experiences branches Sharing know how Sharing documents tutorials and study materials flash Noticeboard Support for e learning Internationalization Requirements Central administrati
50. application Stability of the system is given by stability of each element of the system Any unauthorized action from outside the system can essentially decrease system stability so designing and testing security is also therein very important 8 1 3 Security requirements Web applications contain resources which can be accessed by many users over open network These resources often go over such open routes for example as the Internet Within such environment a substantial number of web application will require some type of security Numbers of web application don t require user registration but Virtual Center for Ed ucators of Seniors is private application not accessible for everyone Because the application is running on the server connected to Internet network there must be implemented some lo gin mechanism and user management to achieve requirement of private accessibility Simple login mechanism without ciphering sends the user name and password unprotected so any cipher mechanism must be also used Registration will be resolved over an admin user with appropriate access rights central security management is one of the application requirements More details about user management will be discussed a bit further More information not only about Java EE security was discussed in Chapter 6 Java EE Security started on page 45 8 1 4 Internationalization and Localization Internationalization is the process of preparing an applicati
51. arUML tool StarUML provides simple and powerful plug in architecture so anyone can de velop plug in modules in COM compatible languages C Delphi C VB By design LAA AtarumL The Open Source UML MDA Platform StarUML 5 0 2 ing of Virtual Center I used last available build on the date 27 August 2006 version 5 0 2 1570 StarUML provides features such as Java C C PHP code generator possible next addons through plug ins own templates support for Enterprise JavaBeans Unfortunately there is no support for Netbeans IDE and there is the only drawback of StarUML according to me Home site of StarUML project is http staruml sourceforge net en 9 3 2 4 DBDesigner DBDesigner 4 is a free available database design system that integrates database design model ing creation and maintenance into a single seamless environment DBDesigner 4 is developed fabFORCE net DB Designer 4 T a se DBDesigner 4 0 5 6 beta and optimized for the open source MySQL Database Together with MySQL server the de veloper has really very good free tool for developing Java Web Application Home site of DBDesigner is http fabforce net dbdesigner4 9 3 2 5 Freemind Freemind is free mind mapping application written in Java Freemind is very practical and effective way to organize ideas Graphical output is very precious but the biggest advantage I FREEMIND 08 0 FreeMind 0 8 0 see in very good use
52. arameter of selected branch Figure 10 5 shows both possibilities of navigation of the branch page ebranch Analogous to branch ebranch displays all related e learning courses according to the branch selected in the menu Navigation and functionality are very analogous with branch page too 76 CHAPTER 10 DESIGN mouse click J SF navigation other way url navigation hy perlink E branch id in SessionBean gt direct navigate via hyperlink navigate to branch by navigation configuration file initialize branch page get id attribut a not null a o T set id variable from attribut default 0 E id from SessionBean NumberFormatException thrown init panelGrid component find tutorials with selected id result ur d Son gt 0 component is rendered d component is rendered e T render response Figure 10 5 Diagram shows how is navigated branch page 10 2 COMPONENT DESIGN 77 tutorial Tutorial page shows the most of known details about selected tutorial Tutorial page is acces sible via many different ways eg from main menu user favourites menu branch page user page User can according to his rights add or delete discuss related with tutorial as well as can watch the tutorial Use Case on Figure is a roughcast of main functionalities of the tutorial page C aaa new related discuss thread gt read tutorial de
53. architecture exporting create or drop scripts reports and so on 5 Destroy Edit pA Querry mode DB Designer support for creating insert delete update or select queries on DB 5 Destroy Edit 8 Microsoft Office Microsoft Office tutorials and hints for all version from 95 2003 Destroy Edit 9 Microsoft Word Microsoft Word 95 2003 all versions tutorials Destroy Edit 10 Microsoft Excel Microsoft Excel 95 2003 all versions tutorials Destroy Edit 11 Microsoft Powerpoint Microsoft Powerpoint 95 2003 all versions tutorials Destroy Edit 12 FreeMind Mind Mapper modeling open source tool tutorials and hints Destroy Edit New vcUser Userld Firstname Surname Username Passwd Email YearOfBirth Gender Locality Skypename leq AvatarFilepath Suspended Approved Lastlogin MM dd yyyy hh mm ss CreateDatetime MM dd yyyy hh mm ss Userprofile Usersettings Roleld Create Show All VeUser Back to index Figure B 8 List page of vc_jpa application false false entity cUserRole roleld 2 entity VcUserRole roleld 3 Figure B 9 New page of vc_jpa application 111 112 APPENDIX B SCREENSHOTS Appendix C Content of CD CDROM demos html index html install cz html install en html app com sun rave sampleapps complibs ajax nbm Firefox Setup 2 B exe Jdk 1_5_8_86 windows i586 p
54. as with file realm User Java EE application users are Similar to operating system users an individual identify that has been defined in the Application Server Users can be associated with a groups Group For example in enterprise information system can most of users belong to the employer group managers in manager group directors to director groups and administrator to administrator group Groups make easier to control the access of large numbers of users Role A role is an abstract name for the permission to access a particular set of resources in a frame of some application A role can be compared with a key that can open a lock There is not essential who you are but what about the role you are associated with Security roles for applications are defined are defined in the Java EE DD file web xml and the corresponding role mappings in the Application Server deployment descriptor file sun web xml It is irrelevant for developers which categories in realm will be defined for the application Java EE platform the security architecture provides a mechanism for mapping the roles defined in the application to the users or groups defined in the runtime realm For such role mapping is used security role mapping element within runtime DD sun web xml 6 4 Secure Connection Using SSL The SSL Secure Socket Layer protocol uses a combination of public key and symmetric key encryption 33 Symmetric key encryption is much faster than p
55. ata object type format e g date format numerical formats Validators check if values delivered by the client are correct for example if the length of a string is correct The view also uses resources that are for example used for localization of the web application Controller The controller in the JSF architecture consists of the front controller Java Servlet class called FacesServlet FacesServlet instance accepts incoming requests passes them to the life cycle for processing and initializes resources The configuration file named faces config xml is a centralized point for managing resources of the web application It defines navigation according to results of processing in the backend and therefore determines which view is to be rendered next Notice that Netbeans IDE uses other conventions and divides faces config xml into more separate configuration files navigation xml for navigation rules managed beans xml to define scope JavaBean objects 4 3 The Life cycle of a JSF Page JSF has very sophisticated system for control its life cycle The whole process consist of six states If a request is received an instance of FacesServlet is created New instance contains whole view structure and represent so current state Figure 4 2 represents following six steps Phase 1 Restore View Immediate after the request is received restore view phase begins View of the page is made and all the event handlers and validators are wired on
56. ations can fire more fine grained events like a changed value in a text field or a clicked button mouse moving and so on A web application has to process all request parameters in order to discover which event occurred JSF provides a stateful component model in addition to fine grained events for building event driven web applications 25 26 CHAPTER 4 JAVASERVER FACES Model As well as it was described in section 1 2 page 6 about architecture of Java EE applications model component is composed from business objects in this case JavaBeansTM components These JavaBeans may be persisted through an underlying persistence layer and a database through the use of JDO Java Data Objects Enterprise JavaBeans or an ORM Object Rela tional Mapping implementation like Java Persistence 5 View Main part of the view tier is a tree of components called with the same name view Components can be rendered in different ways depending on client type but appropriate renderers have to be firstly implemented Additional delegates are validators and converters which can be attached pz Component Tree N Component Delegates Resources Model Renderers Property files Validators JavaBeans JavaBeans Converters XML descriptor Figure 4 1 JSF View tier to specific components in order to validate or convert the values entered by the user Converters provide functionality such as converting data from String to another d
57. ause of Serializable interface and persistence annotations are used within Obtaining access to an Entity Manager I said that for managing interaction between entity classes and database application is used Entity Manager But there is a question how to obtain access to Entity Manager Entity Manager is managed by container in Java EE server There must also exist any instrument how to obtain Entity Manager for remote clients as well as for JavaBeans components It is logical that remote client can not create new instances of Entity Manager because Entity Manager is for him a remote object So in Java Persistence exist object Entity Manager Factory which can be injected by using EntityManagerFactory annotation in requesting object From Entity Manager Factory can be yet obtained Entity Manager instance This technique can be used only for container managed components such as JavaServer Faces for example For non container managed objects developer has to include Servlet and ServletContextListener These object can then give the application s beans access to the resources by using PersistenceUnit annotation Accessing Data from the Database We have already obtained EntityManager so we can work directly with database There will be described how to create simple database query on database 50 public List getAnimals throws BooksNotFoundException 51 try d 52 return em createQuery SELECT an FROM Animal an ORDER B
58. avaBeans classes have to contain constructor that takes no parameters JavaBean components can be declared in JSP pages with lt jsp useBean gt component If referenced bean doesn t exist the statement creates a new bean and stores its as an attribute of the session scope object Retrieving of JavaBeans component properties is possible with bean property notation or lt jsp getPropoerty gt element in the JSP page For setting the property value there exist lt jsp setProperty gt element 3 8 Unified Expression Language JSF JavaServer Faces and JSP both have own expression language The expression language included in JSP provides greater flexibility to the web application developer JSF is used for rendering UI Components User Interface Components and need run time evaluation of EL Expression Result s 1 gt 4 2 false s 4 0 gt 0 true s 100 0 100 true 10 10 ne 100 false sita lt p true Sf hip gt hit false 4 gt 3 true 1 2E4 1 4 12001 4 f10 mod 4 2 f empty param Add true if parameter Add is null or a empty String Unified EL Expression Result student name Gets the value of the property name from student bean Sets the value of the property name from student bean during the postback student countCr The return value of the method countCr from user bean Table 3 2 Examples of Java Expression Language expressions Deferred evaluation means that the tech
59. ayed Error System message about A DataProviderException thrown is caught Con nection with database can t be established Tutorial is not stored in the Virtual Center Error System message about A IOException thrown is caught Virtual Center can t write tutorial to the specified storage Suggestion Maybe there is not enough space on the storage Table 10 10 Adding new tutorial 85 86 CHAPTER 10 DESIGN Action Adding e learning course Description Every user with at least vip rights can insert information about existing e learning courses that is visible for another users of Virtual Center Requirements e user account with at least vip rights e knowledge about any e learning course Progress 1 Go to start page of the Virtual Center logged as user Choose e learnings above branches tree in leftstd block Choose the branch where you can insert new e learning course information Go to the bottom of the middle layout where is the label New tutorial Fill the form Press the Create button Navigate to the e learnings and choose the same branch as last time NOoR Wh Possible output OK On the page is list of e learnings related to the selected branch and on the top of the list is your e learning New e learning course information are stored in the Virtual Center Error The e learning you have inserted recently is not in the list There is probabl
60. before next using of virtual center Security constraint are quite large field in Java EE and it is possible to set all constraints entirely in DD but the functionality of such solution is very limited User is able or not to access the resource we can t have different appearance of the page for different user roles we have to implement completely different page for different user roles That was the main reason why I decided for referenced solution Upload binary file tutorial There are several possibilities for uploading binary file although The most JSF solution is using uploadFile component from AJAX JSF components Because I have had a pretty issues in using this upload component there is a skeleton solution of the method by creating new tutorial Firstly the file path from upload component has to be obtained I wanted to store all tutorials into the domain s folder a relative folder path has to be also translated into real path for the operating system Maybe that file path already exist I append also filename with an counter The rest of the createButton_action method creates new record in database vc tutorial table that is very similar to createElearning on Figure 11 1 11 1 3 Issues e MyFaces components don t support Glassfish server but the support is planned into the future This information is gathered from official web page http myfaces apache org compatibility html of MyFaces project up to da
61. box to admin type fill the user name and password and press Login button OK You are redirected to the admin s start page OK You are not redirected to the admin s start page and system message about you are suspended user at the time is caught You are suspended user at the time OK System message about you are not admin is caught Application doesn t know that you are admin user The user who is trying to login into admin UI has no admin rights Error System message about A DataProviderException thrown is caught Con nection with database can t be established Iry again Table 10 6 Login admin Action Login user Description Admin and basic users have both a bit different graphical user interface to improve usability of the application Requirements e user account with admin rights Progress 1 Navigate to login page Possible output 2 Switch combobox to user type fill the user name and password and press Login button OK You are redirected to the user s start page OK You are not redirected to the user s start page and system message about you are suspended user at the time is caught You are suspended user at the time Error System message about A DataProviderException thrown is caught Con nection with database can t be established Iry again Table 10 7 Login user 10 5 ACCEPTANCE TEST Action Tutorial suspending De
62. c branch ColumnName DataType PrimaryKey NotNull Flags Default Value Comment AutoInc branch id INTEGER PK NN UNSIGNED AI parent id INTEGER UNSIGNED name VARCHAR 45 NN description VARCHAR 255 IndexName IndexType Columns PRIMARY PRIMARY branch id vc branch FKIndex1 Index parent id vc user ColumnName DataType PrimaryKey NotNull Flags Default Value Comment AutoInc user_id INTEGER PK NN UNSIGNED AL role_id INTEGER NN UNSIGNED firstname VARCHAR 45 NN surname VARCHAR 45 NN username VARCHAR 45 NN passwd VARCHAR 80 NN email VARCHAR 60 NN year_of_birth INTEGER UNSIGNED gender VARCHAR 6 locality VARCHAR 128 NN skypename VARCHAR 45 icq VARCHAR 20 avatar_filepath VARCHAR 60 suspended BOOL NN approved BOOL NN lastlogin DATETIME create_datetime DATETIME userprofile BLOB usersettings BLOB IndexName IndexType Columns PRIMARY PRIMARY user_id vc user FKIndex1 Index role id 106 APPENDIX A DATABASE REPORT vc_user ColumnName DataType PrimaryKey NotNull Flags Default Value Comment AutoInc user id INTEGER PK NN UNSIGNED Al role_id INTEGER NN UNSIGNED firstname VARCHAR 45 NN surname VARCHAR 45 NN username VARCHAR 45 NN passwd VARCHAR 80 NN email VARCHAR 60 NN year_of_birth INTEGER UNSIGNED gender VARCHAR 6 locality VARCHAR 128 NN skypename VARCHAR 45 icq VARCHAR 20 avatar_filepath VARCHAR 60 suspended BOOL NN approved BOOL NN lastlogin DATETIME create_datetime DATETIME user
63. cating entities prove to one another that they are acting on behalf of specific identities that are authorized for access Java EE differentiate client server and mutual authentication Authorization Authorization is based on identification and authentication and provides controlled access to protected resources Authorization ensures that users have permis sion to perform operations or access data Data integrity Recipient of data sent over an open network must be able to detect and discard messages that were modified after they were sent Confidentiality Confidentiality is used to ensure that informations are made available only for users who are authorized to access it Non repudiation Mechanism used to prove that a user who performed some action can not reasonably deny having done so QoS Quality of Service The system and system data have to be available when needed Auditing System maintaining a record of transactions and security information 6 1 Physical security The computer running the web server should be kept physically secured in a locked area Any backup storage media tapes removable disks etc should be similarly protected 45 46 CHAPTER 6 JAVA EE SECURITY 6 2 Operating system security Application Server runs on any physical server on operation system To eliminate risks associ ated with operation system security developer and administrator of the server must take into account
64. cations in general e Part 2 Virtual Center for Educators of Seniors introduces the VC Virtual Center for Senior s Educators web application as an example for the previously explained technologies and concepts Chapter 7 Introduction presents the Virtual Center contain a plan of the project Chapter 8 Basic Study there are the most important requirements gathered and a Virtual Center specification is made Chapter 9 Analysis contains the analyses of concurrent systems as well as of possible technological solutions and makes the choice one of them Chapter 10 Design contains the design part of the project according to the choose technology and application requirements Chapter 11 Implementation presents the choice of confessed issues as well as some of the most important conventions in Netbeans Java EE development Chapter 12 Testing and Installation contains short installation manuals and summarize all supported tested and finished parts of the VC e Part 3 Conclusion This part concludes the thesis with a discussion of the concepts proposed and results achieved Part I Theoretical Background Java EE 5 Chapter 1 Java EE overview Developers today increasingly recognize the need for distributed transactional and portable applications that leverage the speed security and reliability of server side technol ogy With higher expectations of the customers higher requirements stay before develop
65. ch could be displayed to the user The associated object will not be updated There are also two different viewpoints that is handled by web application Model view which represent data in business logic and presentation view which represent the same data for user by String format JSF technology provides numbers of converter which can be used for conversion data from presentation form into model and vice versa Converter components implement the javax faces convert Converter interface defined by the JSF specification It consists of two methods each one in charge of converting in a particular direction e getAsObject returns Object representation of current data e getAsString returns String representation of current data using for presentation to the user Since converters are pluggable components which can be associated to many different compo nents they provide an optimal reusability JSF defines a set of converters for example for date time and numerical conversions Figure 4 7 shows converter classes defined inside of javax faces convert package 4 4 9 Backing beans Typical JSF application includes one or more backing beans Backing beans are JSF managed beans that are associated with UI components used in a particular page Backing beans are Java classes that contain properties and methods for storing and manipulating the user s data The event handler methods can manipulate the user interface or execute application log
66. d depends on type of incomming request Selected method will delegate to populate the response Indeed developer can override service method from abstract class HttpServlet but with one restriction It s necessary to call super service method to preserve the function ality of the original service method 2 2 3 Writing servlet s destroy method May become that application server want to reclaim some memory or simply shut down For such situations serves destroy method of servlet s objects This method could be invoked by the application server whenever the requirement to remove a servlet from the memory is arisen but there is a potentinal risk of data lost when servlets don t finish properly To eliminate such risk doMethod of servlets has to be implemented as polite It means that no incoming request can be processed until servlet is being in destroying mode which means that no new threads can be created Just remain to wait for finishing of all unfinished thread Threads have to finish properly or have to be interrupted by admin without any data lost After that application server can safely remove servlet s object from the memory If some thread doesn t finish ordinarily admin user has to interrupt their running by hand but such action could cause any data losts or inconsistences Usually destroy methods serve to close opened streams or database connections initialized in init method or to start another
67. d is annotated with javax persistence ManyToOne An example can be more students related to single class of school Many to many The entity instances can be related to multiple instances of each other For example in college each course has many students and every student may take several courses Property field has to be annotated by javax persistence ManyToMany Each from relations multiplicity can be in two directional mode According to owning side of a relationship we recognize these types 1 Bidirectional relationship each entity has a related field or property that refers to the other entity For example if a faculty knows what department instances it has and if depart ments know what faculty they belongs to then they have a bidirectional relationship 2 Unidirectional relationship only one entity has a relationship field refers to another entity For example an order knows what product it orders but product doesn t know which order is ordered by Sometimes some entities are dependent on existence of some another entity For example some project entity has a files entities but when a project is removed files should be also removed Such type of dependence is known as cascade and we have an opportunity such dependence in Java Persistence denote by cascade element 5 1 1 2 Entity Life cycle and Entity Listeners Such as JSF or Java Servlets entities have their own life cycle Each entity can hold one of four states e Ne
68. da 9 3 1 Syntax of JSP directives lt lt lt lt aa 20 3 2 Examples of Java Expression Language lt lt lt lt 44 lt lt 22 3 3 Standard Syntax Versus XML Syntax lt lt lt nn 23 8 1 Table of active user roles lt lt lt lt lt 4 lt 4 4 4 ee 59 10 1 Registration request approving rh 82 10 2 Usersuspending Sagena A A RR AT ERR ln 83 10 3 User unsusp ndine koe Ego yog dk d Doku VBR ee K kok 83 10 4 Switching user roles lt lt lt lt lt lt lt lA 83 10 5 Tutorial deleting ate usen Bein a gu RUE 84 10 6 Kos admin SON ME Ko O 84 10 7 Login User o c deseo S sedenti S te EL a 84 10 8 Tutorial suspending 224 s 85 10 9 Tutorial unsuspending ss 85 10 10 A amp dding new tutonal zaicuckueickegeR RE Les Dean 85 10 11Adding e learning Course 86 10 12Deleting information about e learning course 2 lt lt lt lt nn 86 10 13 Addional tested functionalities lt lt lt lt lt lt lt lt lt 4 44 2 ee ee 86 11 1 Implemented JSF source components lt lt lt lt lt lt lt 4 eee ee 88 12 1 Summary of validation test results lt lt lt lt lt lt lt on 96 XIX Introduction Developers today increasingly recognize the need for distributed transactional and portable applications that leverage the speed security and reliability of server side technology In the world of information technology
69. e Comment AutoInc language id INTEGER PK NN UNSIGNED AI name VARCHAR 45 NN IndexName IndexType Columns PRIMARY PRIMARY language id vc language ColumnName DataType PrimaryKey NotNull Flags Default Value Comment AutoInc language_id INTEGER PK NN UNSIGNED AI name VARCHAR 45 NN IndexName IndexType Columns PRIMARY PRIMARY language_id vc_discuss ColumnName DataType PrimaryKey NotNull Flags Default Value Comment AutoInc discuss id INTEGER PK NN UNSIGNED AI parent id INTEGER UNSIGNED user id INTEGER UNSIGNED tutorial id INTEGER UNSIGNED sw id INTEGER UNSIGNED news id INTEGER UNSIGNED title VARCHAR 256 body VARCHAR 4096 create datetime DATETIME IndexName IndexType Columns PRIMARY PRIMARY discuss id vc discuss FKIndex1 Index tutorial id vc discuss FKIndex2 Index news id vc discuss FKIndex3 Index parent id vc discuss FKIndex4 Index user id vc discuss FKIndex5 Index sw id 105 vc_discuss ColumnName DataType PrimaryKey NotNull Flags Default Value Comment AutoInc discuss id INTEGER PK NN UNSIGNED AI parent_id INTEGER UNSIGNED user_id INTEGER UNSIGNED tutorial_id INTEGER UNSIGNED sw_id INTEGER UNSIGNED news_id INTEGER UNSIGNED title VARCHAR 256 body VARCHAR 4096 create_datetime DATETIME IndexName IndexType Columns PRIMARY PRIMARY discuss_id vc discuss FKIndex1 Index tutorial id vc discuss FKIndex2 Index news id vc discuss FKIndex3 Index parent id vc discuss FKIndex4 Index user id vc discuss FKIndex5 Index sw id v
70. e had very good experiences with using Java together with MySQL on standard desktop applications I choose for demonstrative purposes MySQL 5 database server for this web project too 11 1 Self implementation Following few sections will be engaged with describing some of my own solutions For enclosed parts of codes I ll keep syntax highlighting to make these codes as much readable for readers as possible 11 1 1 Some Netbeans conventions in Java EE development Every IDE as well as Netbeans has its own conventions which should be learned before de veloper starts to use them for software development Such conventions in Netbeans 1 would sectionalize by abstraction level Some of the most important JSF components of the Virtual Center are summarized in Table 11 1 Database handling For binding data from database into Java EE application are in Netbeans Java EE project used by default CachedRowSetXImpl and CachedRowSetDataProvider object RowSet objects are by default stored in SessionBeanl class that is default session scope object in the project While the CachedRowSetXImpl does the real work of inserting data into a database table the CachedRowSetDataProvider provides an easier coding alternative Rather than coding directly to the RowSet can be used the DataProvider methods to access the 87 CHAPTER 11 IMPLEMENTATION scope scope s class usage of the class Application beans ApplicationBeanl not used
71. e when page is compiled into Servlet Inserting page can contain JSP construction which are inserted where directive include stayes in the JSP page Analogous to preprocessor in ANSI C which is started before source is compiled Directive taglib is useful for extending set of available tags Developer can create own tags which are modeled from Java classes that implement special interface Tags could be associated in TL Tag Libraries which are configured by descriptors TLDs Tag Library descriptors So described tags can be used in JSP page after specifying TL by taglib directive 3 3 SCRIPTING ELEMENTS 21 3 3 Scripting elements Scripting elements provide direct including of source code written in Java programming lan guage into JSP pages This code is used by compiling into the Servlet which is invoked by the first run of the JSP page The first scripting elements I will talk about are expressions 3 3 1 Expressions Defined expression syntax is lt expression gt This expression is evaluated converted into String type and then into page Expression is evaluated by every request to JSP page Values of expression are in generated Servlets stored within _jspService Other type of scripting element are scriptlets 3 3 2 Scriptlets It is possible to insert more complex java language code into JSP pages via scriptlets Syntax of scriptlets is following lt Java language code gt Scriptlets can pass many of tasks ex
72. ear separation of the model from the presentation logic is essential in order to be able to use different viewing tech nologies view is responsible for rendering model data for client users Always when data are changed model notifies view about changes in the model controller is the only access point to all actions When reguest for another page comes the controller decides what to show Based on user actions or results of model updates the next view is also selected by the controller There are several possibilities how can developer implement these three tiers Most freguently used are following two ways 1 2 1 1 Modell Modell shown in Figure 1 3 is architecture where presentation and business logic are both implemented by JSP pages or Java Servlets and stored data are accessed by JavaBeans classes Biggest disadvantage of this architecture is junction of presentation and business logic There is no centralized controller where page navigation could be controlled or the request parameters could be processed therefore Modell is a decentralized or page centric approach 5Smalltalk is an object oriented dynamically typed reflective programming language 8 CHAPTER 1 JAVA EE OVERVIEW View Controller Figure 1 3 Model 1 architecture of Java EE applications 1 2 1 2 Model2 The Model2 design introduces a front controller Servlet as a centralized component that pro cesses the client s requests It
73. ection Database design on page 71 The entire data analysis is in my case accomplished maybe a bit substandard in database design part I didn t talk about it but sometime it is very common that analysis and design parts blend together Database design has to meet the needs resulting from data analysis Here are the most important of them in short list that analysis and design parts blend together Here are the most important of them in short list e user role Admin user is special flag allowing admin GUI access discussed in section 8 5 e user User will have user role User will have skypename field User will have list of favourite branches TeachUComp Inc is the only company I have found on internet providing similar type of flash tutorials like virtual Center 63 64 CHAPTER 9 ANALYSIS User will have list of known languages e branch Branches will be ordered in a tree structure e discuss Discuss threads will be ordered in a tree structure e tutorial Tutorial can be voted Tutorial storage will be local for application server view not remote DB Tutorial will know its nominal resolution for optimal sharpness of the picture 9 3 Technology frameworks Using frameworks modern IDEs or design patterns make software development much easier and faster then in the past Because of variety in this branch it is very important to choose the right tools depending on de
74. ecutable with Java This tasks are done by every request on the JSP page because source code of scriptlets is included directly into _jspService method Therefore are all the entities classes methods variables declared within scriptlets like local 3 3 3 Declarations For global declarations exist last type of scripting elements called declaration Entities declared in global are in generated Servlet outside the _jspService method In the case of setting that exist the only instance and for requests are created only threads default such declarations are available for all requests Other possibility is to implement any shared entity as static Syntax for declaration elements follows lt one or many declarations gt 3 4 Commentaries JSP has two types of commentaries The first one so called secret commentary it is a commen tary in active JSP code and such comment isn t included into created HTML code Another type so called output commentary is standard HTML commentary and is included into output HTML 3 5 Tags Tags are elements in JSP that are associated with some functionality The biggest benefits of tags are increased readability and separation dynamic and static parts in pages Still sometimes is composition of static and dynamic elements confusing JSP technology provides inserting of tags into special libraries which are used in JSPs by lt taglib gt elements Standard tags use prefixies jsp It is possible
75. eeds to be at the moment redi rected to a another web application resource that does not contain any JSF components it call FacesContext responseComplete At the end of the apply request values phase each input component has an up to date value based on the values submitted through the current client request Phase 3 Process Validations Phase All values are stored in components but are not validated In this phase values are compared with specified rules This may involve component s validators or external validators associated to the components A negative validation process cause invalidation of related component Af ter that JSF skips on the render response phase and error message is populated If any validate method or any listener call renderResponse method on the current FacesContext JSF skips to the render response phase If the application needs in this phase redirect to be redi rected to an other web application resource FacesContext responseComplete method should be called If any listener event arise interested listeners are broadcasted by JSF 28 CHAPTER 4 JAVASERVER FACES Phase 4 Update Model Value Phase All component values are valid in proper form and it is also safe to update all values of the back ing beans or model objects against the component values If the local data cannot be converted to the types specified by the bean properties page is rendered with error displayed Error mes sage will be
76. emented like a thin client using common web browser Finally the Virtual Center will be supported by Internet Explorer 5 and newer Mozilla Firefox 1 5 0 9 and newer and Opera 9 0 and newer Support for another browsers or older releases of enumerated will not be tested during application development process All the 8 5 USABILITY BOUNDS SETTING A Registered 61 Ae Figure 8 6 answer lt include gt gt lt lt include gt gt Play Tutorial Find tutorial BET lt extension points lt lt extend gt gt skype Remove from favourites In no initial report but D answer on some existing Find discuss thread lt lt include gt gt where D0 Add discuss extension points Check suspend approve states System lt lt include gt gt admin privileges If user want to login 3 Authenticate extension points login type lt lt extend gt gt lt lt include gt gt lt lt include gt gt If skypename is not null D lt lt include gt gt If user hasn t item in the list extend Find in the list extension points result size Partition of Use Case for registered user 62 CHAPTER 8 BASIC STUDY same the application will generate valid HTML 4 01 code as possible should be also well displayed by another clients too At the time there is planned no explicit support for using of application on mobile
77. eming resources FileDirContext file Strina Take Snapshot Live Resuks 6 Reset Collected Resuks E Saved Snapshots WebApplcation org apache naming resources FileDirContext FleResourct com test QueueTest flip int org apache naming resources ProxyDirContext lookup org apache catalina loader WebappClassLoader findLoa EE Method Name Fiter m Telemetry Ouro output Ehre Montor Figure B 4 Play page Virtual center for educators username helenka holikova lastlogin 2007 01 13 16 21 23 Firstname Jarda favorite tutorials Surname Kortus NetBeans Mobility v Username jarda kortus Details Age 25 Gender male favorite users B skype e mail leq 220308780 Locality Prague Czech Republic Interests Visual Web Pack DB Designer Languages english czech german last login 2007 01 14 05 38 56 Add to favourites Exclude from favourites lt lt Related tutorials title 4 create date SOA in Netbeans 30 11 2006 Overview of Visual Web Pack 2 11 2006 JSF in Netbeans 21 9 2006 Profiling Web applications 13 8 2006 NetBeans code completion features 18 6 2006 en Netbeans with integrated CVS 22 3 2006 NetBeans Mobility 15 3 2006 Figure B 5 User page 110 APPENDIX B SCREENSHOTS Virtual center for educators OME username jarda kortus in tutorials Search Delete
78. en declarative security alone is not sufficient to express the security model of an application 6 4 SECURE CONNECTION USING SSL 47 6 3 1 Realm User Group Authorization process is based on identification and authentication Identification is a process which enables recognition of an entity by a system and authentication is a process that verifies the identity of a user device or other entity in a computer system usually as a prerequisite to allowing access to resources in a system Realm For a web applications a realms are a complete database of users and groups that identify valid users of a Web application or a set of Web applications and are controlled by the same authentication policy Java EE recognize three types of realms 32 file server stores user credentials locally in a file named keyfile For managing users in file realm can be used Admin Console This realm is used for the authentication of all clients except for web browser clients that use the HTTPS protocol and certificates certificate server stores user credentials in database When using certificate realm the server uses certificates with the HTTPS protocol to authenticate web clients To verify the identity of a user in the certificate realm the authentication service verifies an X 509 certificate admin realm server stores user credentials locally in a file named admin keyfile For managing users in file realm can be used Admin Console in the same way
79. enterprise applications must be designed built and produced for less money with greater speed and with fewer resources Architectures of today s enterprise applications have become increasingly server centric Application functionality which used to be implemented within a fat client application running on clients machine now resides on a central server instance Responsibilities of the client application are scaled down to presenting the UI User Interface and to acquite of user s input making thin client By programming of multitiered web applications developers get into touch with some different technologies application servers tools and proceedings Due to an extent of this topic some initial knowledges are exacted of readers Firstly the reader should be familiarized with the Java programming language Good way to get to that point is to work through all the basic and some of the specialized trails in 1 2 and 3 Next necessary prerequisities are good knowledge of HTML and at least basic imagination about XML technology The readers who are not familiar with HTML or haven t at least initial knowledges about XML are highly encouraged to read some of many books engaged in this topics By own experience I recommend these several books about HTML 4 5 6 and XML 10 9 There is a lot of another quality literature focusing on these areas therefore I will let the final choice on reader s personal decision Objectives I wi
80. er stealing the encrypted password database e Platform specific risks Most operating systems are insecure by default when they arrive new out of the box Vendors of operating systems and application software reg ularly patch issues to fix serious security weaknesses in their software Security patches must be applied on a timely and ongoing basis Logs Logs help ensure accountability Knowledge that logs are kept acts as a deterrent to abuse Logs are also essential in investigating incidents after the fact Logs are typ ically created both by the operating system as well as by applications like web servers mail servers etc To ensure integrity logs should be written to another computer when ever possible Logs often contain sensitive informations such as dates and times of user accesses Logs containing sensitive informations should be accessible only by authorized staff and should not be accessible as public 6 3 Application security Securing containers Java EE containers are parts of Application Server and are responsible for providing application security In Java EE containers ensure two types of security declarative and programmatic Declarative security expresses an application component s security reguirements using DD In our case DD for web application is named web xml Programmatic security on the other side is embedded in an application and is used to make security decisions Programmatic security is useful above all wh
81. er web application development are to keep some conventions Today developers more often disuse dynamic navigation menu because of different visibility in different web clients Another philosophy could be to identify which web client application user uses and then can be rendered different navigation menu according to the client type Such solution is not systematic and it 10 3 GRAPHICAL USER INTERFACE 79 is very difficult to maintain such application for all users using different web browsers in the time apart from JavaScript support necessity Other convention is to divide the whole gui into separate parts divs according to their functionality Sure I mustn t forget on requirement to write valid HTML code The other practice and one of the most important principles in multi tier applications user interface designing is to fully separate user interface design from the business logic JSF technology enable more then dividing of these parts one from another actually it is possible to create absolutely different renderers for different devices opening the same application Devel oper only needs to implement such renderers I talked about renderers in section 10 5 talking about UI Components and Component tree in JSF 10 3 1 Page framing I decided to divide typical page s scheme into four separate blocks topstd Top standard block Most of the navigation will be concentrated in other blocks Topstd panel will also rather serve to i
82. eraction with the backing data model and managing validation conversion and rendering To simplify the development of custom user interface components a subclass of the UIComponent named UIComponentBase provides default implementation for all methods so a developer has only to extend necessary methods without writing the whole component from scratch 30 CHAPTER 4 JAVASERVER FACES lt lt interface gt gt lt lt interface gt gt lt lt interface gt gt lt lt interface gt gt EditableValueHolder ValueHolder StateHolder ActionSource UIComponent UlComponentBase UlOutput UlCommand lt lt interface gt gt Interface Ulinput Class Figure 4 3 UI Component and UlComponent Base Classes 4 4 2 FacesContext The FacesContext holds all contextual information about view and defines methods used during the request processing life cycle It includes the following elements 1 ExternalContext providing access to the container environment mainly the surround ing Servlet API UIViewRoot represents root of current component tree RenderKit is a collection of renderer instances that know how to render JSF UlCom ponents for specific client The response can be sent either through a ResponseStream or ResponseWriter object while the first one is used for returning binary c
83. ers In the world of information technology enterprise applications must be designed built and produced for less money with greater speed and better application performance To realize such wants Java EE emerged The Java EE defines standard for development enterprise multi tiered applications and 26 Entity 27 Table name cd 28 NamedQueries 29 GNamedQuery name Cd findByCdId query 30 SELECT c FROM Cd c WHERE c cdId cdId 31 NamedQuery name Cd findByAuthor query 32 SELECT c FROM Cd c WHERE c author author 33 NamedQuery name Cd findByTitle query 34 SELECT c FROM Cd c WHERE c title title 35 NamedQuery name Cd findByYearCd query 36 SELECT c FROM Cd c WHERE c yearCd yearCd 37 NamedQuery name Cd findByRating query 38 SELECT c FROM Cd c WHERE c rating rating 39 40 public class Cd implements Serializable 41 42 Id 43 Column name cd id nullable false 44 private Integer cdld Figure 1 1 XML annotations in source code provides a powerful set of APIs Application Programming Interfaces which make development easier and faster than earlier Simultaneously Java EE 5 uses all benefits from J2SE such as platform independence portability across different types of computer s architecture naming service for access to resources stored in tree type structure or security of application As well Java EE provides full support for
84. ersistence applied only on parts of the entire Virtual Center application Netbeans is also advised by Sun Microsystems Inc that is the most contributor of Java programming language I think that Netbeans is up to date compared to Eclipse project much more progressive improving environment on the Java programming language IDEs market As well I think that Netbeans is much more usable for developers compared with Eclipse too note that Netbeans development team has 25 quality engineers Features in Netbeans e Direct support for Sun Java Application Server PE 9 Glassfish Applications can be deployed into Server direct in Netbeans and then is Server configurable direct from Netbeans nearly in the same way as by Server s configuration console Direct support for numbers of database servers such as MySQL Java DB Oracle De velopers can write and run SQL scripts directly from Netbeans IDE It means that it is possible to connect into selected database and create another new database too SQL ed itor knows SQL syntax and include syntax highlighting that makes scripting in Netbeans more attractive Note that up to date is in Netbeans no code completion s support for SQL file types Direct support for Java Persistence Netbeans contains many wizards for creating Java Persistence classes e Graphical Support for creating XML Deployment Descriptors for Web applications Configurable syntax highlighting for different types of documents refac
85. es are at client disabled ID has to be sent by every request and response Every hyperlink s url has to be also encoded to contain this ID 2 6 Sharing information Java Servlet specification apply four types of so called scope objects Web Context Session Request and Page These objects are used when the developer want to share some data between more than one component Shared data are in this case attributes Each shared attribute in any scope has its own get setAttribute methods like a setter and getter for the attribute We have to be very rigorous when declaring such sharing object so that implement synchronized access to all the shared parameters 2 7 New features in Servlet 2 5 I m going now explain what new features are in Servlet 2 5 and what are their biggest benefits ReguestDispatcher object can be obtained from either a request or the web context but usually the request object is used 6See 2 4 1 for information how to obtain RequestDispatcher object Element s value has format of integer which means how long will session object store until its invalidity in minutes 5Servlet has to use response encodeURL method with every URL 2 8 WHY SERVLETS OVERRUN CGI 17 e Dependency on J2SE 5 0 new features of J2SE autoboxing new enum type meta data annotation are guaranteed to developers by programming Java Servlet 2 5 e Annotations I have discussed about annotations in Chapter 1 a bit See page 5
86. events can be processed during the invoke application phase or the apply request values phase and value change events can be processed during the process validations phase or the apply request values phase Action event occurs when the user activates a component which implements the ActionSource interface These components include buttons and hyperlinks Data model events occurs when data components process a row of their data Unlike the pre viously named events datamodel events are not fired by user interface components Classes derived from the javax faces model Datamodel class allow the registration of listeners those take care of handling data model events Since it is not a Ul component the listeners are associated to the registration can only be done in the Java code rather than binding it to a component in the view The Datamodel class is a wrapper around different data binding technologies with its underlying data modeled as a collection of objects that represent the data rows This wrapper allows to use common data source objects such as a JDBC ResultSet or a JSTL Result The development of JSF listeners consist of e Implement own event listener class e Implement method of backing bean which will handle events and refer to this method via an expression associated with attribute of the component s tag All events are queued in the FacesContext After each phase of the request processing life cycle events with the appropriate P
87. exe mysql connector java 3 1 12 zip mysql essential 5 8 24a win32 msi mysql gui tools 5 8 r3 win32 msi netbeans visualweb 5_5 windows_8612 exe Opera 9 802 Eng Setup exe sjsas pe 8 Bi nb 5 5 win exe sjsas pe 9 8 Bi vindous exe vink28 exe emos demos html rc 9709104 vc firstpart swf 078184 vc secondpart swf installi swf vc JPR suf epository hesis latex ther sources rint thesis pdf build US ist vc war javadoc lib etup jdbc_dataSource sun resource mysqlPool sun resource rc est c_JPA Presentation demos Welcome project page Installation manual Czech language gt Installation manual English language directory where you can find useful applications AJAX components module for Netbeans 5 5 Mozilla Firefox internet web browser JDK 1 5 for Windows XP lt Cother versions on http java sun com downloads index html gt MYSQL JDBC connector library version 3 1 MYSQL Server 5 MYSQL GUI tools for working with MySQL database in visual way Visual Web Pack for Netbeans 5 5 Opera Web Browser 9 Sun Java System Application Server 9 Netbeans 5 5 Sun Java System Application Server 9 Conly gt Wink 2 8 application for creating Flash tutorials HTML file for accessing flash tutorials Demo Virtual Center First part Demo Virtual Center Second part Demo lt Deploying and starting of the Virtual Center Demo Virtual Center Table manager application created by JPA
88. fic Java EE services for contained application components Following containers are parts of Java EE Java EE Server Runtime portion of Java EE product A Java EE server provides next two containers EJB Container and Web Container EJB Container An EJB Container Enterprise JavaBean Container hosts EJB compo nents and manages their execution and life cycle An EJB Container also provides addi tional services like transaction control persistence management and security services to EJBs Web Container A Web container provides network services for executing of JSP pages and Java Servlet components of Java EE applications Web components and their container runs on Java EE enabled server machine Application Client Container An application client container manages the executing of client components Application client contains JRE Java Runtime Environment and runs on the client machine 10 CHAPTER 1 JAVA EE OVERVIEW Applet Container Manages running of Java Applets Applet container consist of Java Applet plug in integrated in a web browser and the browser The Applet container runs on client machine 1 5 Java EE APls In Java EE 5 is available fourteen APIs more then in older version J2EE 1 4 It is the biggest difference between J2EE and Java EE All these APIs can developers use during Java EE application s development processes Of course there are neither enough place for describing every one of them nor
89. g Deployment Descriptor Access to output stream via getWriter or getOutputStream method according to type of the stream Setting content type Operation which have to be called before response is committed For more information about content types see IANA Buffering the output Allows more time for Servlet to set a proper status codes and headers or to forward the control to another component By default the buffering is disabled Servlet could buffer its response to avoid sending partial response following by error message Setting localization informations e g document encoding Status code field for representing status code e g when Servlet cause any exception or when reguest is redirected Cookies field to store application specific informations at the client side Previous section discussed about filtering reguests and responses There are another two pos sibilities how to affect final response Assigned Numbers Authority IANA Organization dedicated to preserving the central coordinating func tions of the global Internet for the public good 20 16 CHAPTER 2 JAVA SERVLETS 2 4 1 Including other resource There are two possibilities how to invoke other web resource directly or indirectly A web compo nent indirectly invokes another web resource when it embeds URL to another resource To direct including other resource an include method of dispatcher object has to be called To in voke a resource ava
90. g to introduce the most freguently used of them 2 4 CONSTRUCTING OF RESPONSES 15 27 lt filter gt 28 lt filter name gt F1 lt filter name gt 29 lt filter class gt filters F1 lt filter class gt 30 lt filter gt 31 lt filter gt 32 lt filter name gt F2 lt filter name gt 33 lt filter class gt filters F2 lt filter class gt 34 lt filter gt ab filter 36 lt filter name gt F3 lt filter name gt 37 lt filter class gt filters F3 lt filter class gt 38 lt filter gt 39 40 lt filter mapping gt 41 lt filter name gt F1 lt filter name gt 42 lt servlet name gt S1 lt servlet name gt 43 lt filter mapping gt 44 lt filter mapping gt 45 lt filter name gt F3 lt filter name gt 46 lt servlet name gt S1 lt servlet name gt 47 filter mapping 48 lt filter mapping gt 49 lt filter name gt F1 lt filter name gt 50 lt servlet name gt S2 lt servlet name gt 51 lt filter mapping gt 32 lt filter mapping gt 53 lt filter name gt F2 lt filter name gt 54 lt servlet name gt S2 lt servlet name gt 55 lt filter mapping gt 56 lt filter mapping gt 57 lt filter name gt F3 lt filter name gt 58 lt servlet name gt S2 lt servlet name gt 59 lt filter mapping gt 60 lt filter mapping gt 61 lt filter name gt F1 lt filter name gt 62 lt servlet name gt S3 lt servlet name gt 63 lt filter mapping gt 64 Figure 2 4 Filter to Servlet Mappin
91. g doc refman 5 0 en index html Alternative database servers are Oracle PostgreSQL Derby database distributed with Application Server and many others Homepage of Apache Software Foundation is http www apache org 70 CHAPTER 9 ANALYSIS Chapter 10 Design Design part of sw development life cycle should start after finishing previous parts because all the requirements including possible extendability of an application used technology frame works etc should be already known and design has to take all these apects into account Within my project of Virtual Center I see just here the greatest imminence of the whole developent process Explanation comes through Although I have made very intimate analysis of possible user from last chapter and all the requirements were determined according to him it is probable that as early as during multiyear usage of the application there will be rising new and new requirements It is also one good reason for using component based framework for development because finished components should be very simply reused 10 1 Database design For demonstrative purposes will be used free MySQL database version 5 because of very good experiences with MySQL 3 together with J2SE application development open source philosophy and very good documentation built on wiki engine The whole ER model including some up to date unused entities like vc_elearning or vc_news is on Figure 10 1 on page 72 in crow
92. g the local data of editable compo nents such as text fields Validators are used to prevent application in improper behavior Additionally many of the security and stability problems in web applications are caused by in correct format of input data submitted from the client On Figure 4 6 you can see all standard validation classes One or more validators may be associated to a UI component that implements the EditableValueHolder interface defined in the JSF API This means that the component can hold a value like e g textFields A validator associated with a component checks the local value of the component during the process validations phase page 27 Request processing lifecycle Validation can be implemented by developer in two ways 1 Direct validation can be simply implemented by overriding validate method of the UIComponent superclass Validation logic is encapsulated into UIComponent and there fore is not usable by other UlComponents 2 Delegated validation provides two types for implementation of validators One possibility 44 JSF DEVELOPMENT PROCESS 35 javax faces validator lt lt interface gt gt Validator validate context FacesContext component UlComponent value Object void LengthValidator LongRangeValidator DoubleRangeValidator MAXIMUM MESSAGE ID String MINIMUM MESSAGE ID String NOT IN RANGE MESSAGE ID String TYPE MESSAGE ID S
93. get the information about of their value s invalidity Rest of the life cycle phases are skipped because there is a potential risk for the data integrity when the data submitted by user are invalid An error message notifying user about wrong input is appended to the response Another possibility to validate user s data is to implement JavaScript code which will validate data on the client s side The only advantage of this method is decreasing of necessary request response cycles because data needn t to be sent on server for validation The major drawback of client side validation is that a lot of web clients don t support Java Scripts It is not sure that the data would be validated JavaScript is a prototype based scripting language with a syntax loosely based on C The language is best known for its use in websites but is also used to enable scripting access to objects embedded in other applications 36 CHAPTER 4 JAVASERVER FACES 4 4 8 Converters A converter is used to format an object to a nicer text to be displayed For example if you want to display a date in JSP you can use a converter to reformat the date in form which user understands like 10 03 2005 But there is another way to use a converter If you use them in conjunction with an input control the user s input must be in the format specified by the converter If the format of the input doesn t match the format you can throw an exception in the converter whi
94. haseld of the current life cycle phase are broadcasting to registered listeners It means that the appropriate event handling methods are invoked on the listeners It is important to distinguish between the event model of a standard desktop and a web based application The latter always needs a request response cycle for recognition events Therefore it is not possible to react in the server side immediately to user s input Figure 4 5 shows the classes and interfaces of the javax faces event package It in cludes the standard events and listeners defined through the JSF specification FacesEvent FacesListener and EventListener do not contain any methods that have to be im plemented and are therefore called tagging interfaces These are only used for grouping of subclasses in an object hierarchy 34 CHAPTER 4 JAVASERVER FACES E java util EventObject lt lt interface gt gt java util EventListener source Object EventObject source Object EventObject getSource Object toString String lu I i javax faces Event lt lt interface gt gt I PhaseListener PhaseEvent i lt lt interface gt gt FacesListener afterPhase event PhaseEvent PhaseEvent context FacesContext phaseld Phaseld lifecycle Lifecycle PhaseEvent beforePhase event PhaseEvent getFacesContext FacesContext getPhaseld Pha
95. hat JSF will become the standard solution once it is included into the Java EE platform as proposed by Sun Microsystems Inc 4 1 What is JavaServer Faces JSF specification says that it is a server side UI component User Interface Component frame work for Java technology based web applications There are two main components of JSF technology JSF API for representing UI components and managing their state Two custom tag libraries for expressing Ul components within a JSP and for wiring com ponents to server side objects JSF UI components are stateful which means that components keep their state and value across multiple client requests When using HTML JSP as the viewing technology for JSF UI com ponents are mostly a one to one mapped to the HTML form elements This component model also opens up the opportunity for the appearance of RAD Rapid application development Tools that allow to develop simply by arranging Ul components in a visual development tool JSF uses Model2 architecture section 1 2 1 2 on page 8 so there are also benefit of separation of presentation logic and data Every from these three parts can be changed without necessity of changing any other part 4 2 The MVC architecture of JSF Main drawback of Model2 architecture in compare with SWING Java applications results from the fact that HTTP is a stateless protocol The only event that is recognized by a web ap plication is the HTTP request while GUI applic
96. he object oriented view in the presentation layer and possibly also in the business layer Java Persistence is not only an API for mapping such mismatched data models but it is complex Java EE conception containing Java Persistence API and the query language 5 1 Java Persistence API Nowadays the most accepted solution to bridge the object relational gap is a technique called ORM Object Relational Mapping that mediates between the object oriented view of the application and the relational tabular data representation of the relational model Tabular data is mapped to persistent Java objects which allow data access in form of objects containing the data of a particular row in the database Java object that maps to a database table is called an entity class It is a regular JavaBeans component also known POJO Plain Old Java Object with properties that are mapped into columns in the database table To manage the interaction I SEUS PUBLIC CLASS STUDENT w private int ID private String NAME STUDENT ID NAME RC BRANCH M private String RC private String BRANCH Figure 5 1 Object Relational Mapping of entities with the Java Persistence facility applications use the EntityManager interface The set of entities that can be managed by an entity manager are defined in a persistence unit which is configured in persistence xml file In this section I ll describe how create link such as you can see on the Figure 5 1 Following secti
97. ic in the backend Each of the component properties can be bound to one of the following e A component s value e A component s instance e A converter instance e A listener instance e A validator instance The most common functions that backing bean method perform include the following e Validating of component s data e Handling of an event fired by a component e Processin to determine the next page to which the application must navigate Navigating When a bean property is bound to a component s value it can be any of the basic primitive and numeric types or any Java object type for which the application has access to an appropriate converter Also property can be Date type if the application has access to a converter that can 44 JSF DEVELOPMENT PROCESS javax faces convert BigintegerConverter BIGINTEGER ID String CONVERTER ID String STRING ID String getAsObject context FacesContext component UlComponent value String Object getAsString context FacesContext component UlComponent value String String lt lt create gt gt BigIntegerConverter BigIntegerConverter EnumConverter CONVERTER_ID String ENUM_ID String ENUM_NO_CLASS_ID String getAsObject context FacesContext component UlComponent value String Object getAsString context FacesContext component UlComponent value String String lt lt create gt gt EnumConverter EnumConverter NumberCon
98. ield and it is also not possible to cover every element of Java EE architecture or development process within this thesis An intention was to give essential overview about architecture and development principles in Java EE for the reader Simultaneously I thing that the thesis contains description of new elements in Java EE version 5 and in addition I tried to give enough arguments why I thing that Java EE is better than Microsoft NET page 64 in field of web development For more informations about Java Java EE web development multitier architecture object relational mapping Netbeans or other described technologies and tools you can consult with some of referenced bibliography starting on the page 115 Second part of the thesis presents Java EE technology and development tools on cre ation really existing system The Virtual Center for educators of seniors VC which is the main deliverable of the EU SENNET project should provide a stable platform for building e community VC should be able to gather knowledges and best practices helping to improve the professional qualifications and skills of its individual members Although the main target group of the project are educators of seniors it will in the end just the seniors themselves will 99 100 CHAPTER 13 CONCLUSION benefit from the outcomes of the project In this way more and more seniors will be integrated into the information society Although VC covers all requirements
99. ilable on the same server you have to firstly obtain a RequestDispatcher object by using a getRequestDispatcher method from request object 2 4 2 Transferring Control to Another Component You might want to partially process a request and then transfer to another component depend ing on the nature of the request To transfer the control invoke the forward method in RequestDispatcher Note that if you have already accessed a ServletOutputStream or PrintWriter object within the Servlet you can t use this method since an IllegalStateException would be thrown 21 2 5 Session management Every web based application is responsible for maintaining information based on user s connec tion In Java EE this information are stored in object representing instance of HttpSession class and called simply session In Java Servlet Technology exist numbers of principles that are very important for life cycle of client s connection Session has usually limited life span set by setMaxInactiveInterval and accessed by getMaxInactiveInterval As well this value can be set in DD with session time out element inside of session ele ment An obligation of the server is to associate session objects with connected users Sessions have usually for this purposes unique identification numbers session ID Every user has to know which IDs are associated to him Common prodecure is that cookies look after user side maintaining of this ID When cooki
100. it is scope of this thesis On Figure 1 5 is reader able to see how could Java EE developer user these APIs to achieve user s aims within the enterprise application Applet Container J2SE Y Web Container EJB Container JSP Servlet gt JSP Servlet L Ru Z e lr LLE wa RSS 3 ell a n Mai MESE a u Mai 2 zz alelse leis isle 8125 2ja AP ERREGEEEPEE jalo 5 3 4 5 gt 3 S e 3 5 dara Es aer x 8 amp 8 Jal 8 8 JAF 33518 2 8 JAF SAAJ EJES SAAJ EJES J2SE J2SE A Application Client Container Application Client E 23 m Erp UXV SWS SOOIAIOS QIM eyepey SM juowoseuryy oouojsIsJoq esef XVIS JN un tm Figure 1 5 Java EE Platform APIs Following several chapters will discuss about major part of Java EE components and about one new API in Java EE JPA Java Persistence Chapter 2 Java Servlets Java Servlets are Java programming language classes that dynamically process requests and construct responses Every Java Servlet class extends javax servlet interface Notice that Java Servlet technology is the foundation of all the web Java EE technologies and so Ill talk very throughly about this topic The original specification
101. ith commas gt Gi Message Security Y Figure 6 1 Creating user in file realm by Admin Console application console of Application Server On Figure 6 1 is shown how to do this task 50 CHAPTER 6 JAVA EE SECURITY 6 5 2 Resource constraint in Java EE Application Now I have one user jan novak in teacher group of file realm of Application Server and I would like to make any resource accessible only for users in teacher users group In Java EE are two ways how to pass this requirement Through an Annotations or Application DD 34 Annotations have in most cases some advantages such as clearness but for security constraints is in my opinion better to use DD When both method annotations and DD are used DD is dominant When I use some of components created by another developers I have assurance that my option is dominant only when I use DD On Figure 6 2 is any example how to specify security constraints with DD web xm1 on any type of requests on JSF pages which are mapped into faces x path 34 lt security constraint gt 35 display name Constraintl display name 36 lt web resource collection gt 37 lt web resource name gt JSF lt web resource name gt 38 lt description gt 39 lt url pattern gt lt url pattern gt 40 lt url pattern gt faces lt url pattern gt 41 lt http method gt GET lt http method gt 42 lt http method gt POST lt http method gt 43 lt http method gt HEAD lt http method gt 44 lt
102. lastlog n nue tutorials e learnings favorite tutorials B v NetBeans favorite users B 7 Profiler Mobiity 7 Visual Web Pack v DB Designer Design mode Cj Query mode v Microsoft Office 7 Word Sess MS Word vs Typewriter P back to branch PORTO Contact arpoi Do not use typewriter any more Course about MS World will start on Monday t is14 01 2007 absolutely free for seniors contact 24585458754 Top rated tutorials MS Word vs Typewriter 14 01 2007 DebugMode Wink lt A natDaona M Figure B 6 Elearn page irtual Center Table Manager List of VcUserRole List of VcUser List of VcTutorial List of VcTutVote List of VcLanguage List of VcInterest List of VcElearning List of VeDiscuss List of VcBranch Figure B 7 Index page of vc jpa application Listing VeBranchs New VcBranch Back to index Item 1 12 of 12 BranchId Name Description ParentId yl NetBeans Netbeans IDE tutorials and articles Destroy Edit 2 Profiler Netbeans Profiler for profilng web and standard desktop applications 1 Destroy Edit 3 Mobility Netbeans IDE support for developing J2ME application for mobile devices 1 Destroy Edit 4 Visual Web Pack Netbeans IDE support for developing Java EE application in visual way 1 Destroy Edit 5 DB Designer Utility for designing DB architecture Destroy Edit 6 Design mode Design mode for building DB
103. ll be designed in the scope of this report After corrections all affected tests will be revised In case of extensive corrections new set of tests have to be scheduled All the test reports will contain date test fulfillment characteristics and headline of testing results In conclusion will be these results compared with requirements and component will be evaluated according to them 10 5 Acceptance test Acceptance test is build on user requirements and on application functionalities Acceptance tests are black box system tests Each acceptance test represents some ex pected result from the system Customers are responsible for verifying the correctness of the acceptance tests and reviewing test scores to decide which failed tests are of highest priority Acceptance tests are also used as regression tests prior to a production release Acceptance tests should be automated so they can be run often The acceptance test score is published to the team It is the team s responsibility to schedule time each iteration to fix any failed tests 82 CHAPTER 10 DESIGN 10 5 1 Conditions of acceptance tests The Virtual Center application will run on the server machine and the connected database runs on the same computer or on another one For testing modules is necessary to ensure access rights to the application module and to the operation system on the computer where the application runs In the database is implicitly created admin account
104. ll make short introduction into Java EE 5 application development process and present basic principles in developing such as for example describing of application life cycles As well I will insert some short examples directly into the appropriate sections of the thesis to clarify described theory Therefore I believe that the thesis will be very interesting and intelligible for Java developers as well as for non Java expert readers like other university students or Java EE beginners In the second part of the thesis I will design and implement the virtual center for educators of seniors Fractions of analysis design implementation or another part of the project will be presented in this second part of the thesis too The third part of the thesis will describe achived results The HTML HyperText Markup Language is a predominant markup language for the creation of web pages 2The XML Extensible Markup Language is a W3C recommended general purpose markup language for creating special purpose markup languages capable of describing many different kinds of data Structure of thesis The thesis itself is divided into two parts The first part guides a reader through extensive theoretical background of Java EE 5 technology The second one demonstrates development of specific Virtual Center for Educators of Seniors application At the end I will summarize whole work Ill try to evaluate main advantages and drawbacks of Java EE technology in this thesis
105. m uso Ep nb mom poh ma ae B vb dpi s 2 Java Servlets DL sServlet VS LOGIA AA AAA AAA vu 2 2 Servlets life cycle 24 nart ae a A AS A ec 2 2 1 Writing init method ees 2 2 2 Writing doSomething Method lt lt lt lt 2 2 3 Writing servlet s destroy method 2 3 Filtering Request and Responses 2 lt lt lt lt lt lt 4 ee 2 3 1 Creating of filter classes lt lt en 2 4 Constructing of responses ooo 2 4 1 Including other resource lt lt en 2 42 Transferring Control to Another Component 2 5 Session management lt lt lt lt lt lt 4 4 nn 2 6 Sharing information e 2 7 New features in Servlet 2 5 aaa 2 8 Why Servlets overrun Gl aa 3 JavaServer Pages Technology 3 JS Pis Litescycle amp a DA A O aud a ul y e sony 9 2 Directives near ro Zone ne a eet cd mE Eae 3 3 Scripting elements psr sei Eg an ea BR a 3 3 1 VEXPTESSiONS us 2 3 ns alt a Dee eros balk Ld 3 3 2 7 SCL pulets Aa ordures Mana e EO De teeth is 3 3 3 Deelarations sese sani xoxo xoxo 3 Xo ee SUA B ROS kotvu 39 4 CommentarieSo s o o ooh oho 9 dou dos o3 Xo E 4c Uh OR Sow kcal or x RU xviii xix w O OO oo C II SN E A Ali eu Dee Pak ee de ee ve 3 6 Sharing objects lt lt lt lt lt lt lt ee 3 7 JavaBeans Components 3 8 Unified Expression Language ee 3 9 JSP Documents cis RR
106. med The middle layout The middle layout block is the main part of displayed page Other three parts are included into this main part as three separate frames The middle layout is predeterminated for displaying most of the information that user is actually interested in This part of displayed page is for every other page different 10 3 2 Colors Very important part of graphical design is also color adjustment I choose from modest colors between blue and green for the bulk of whole graphical design The important parts I colored by red or another well contrasting color according to the neighborhood of the part The obligatory fields are marked by red asterisk mark 80 CHAPTER 10 DESIGN 10 3 3 Ordering According to my own experience when the page contains more elements like tutorials for example 1 prefer to order them into a grid e g like some e shops does This is a bit problem to make a grid in strict JSF component structure of the page It is not possible to use elements like lt h foreach because life cycle of JSF components differs from simple HTML or JSP components One solution is to create a GridLayout or any other with one column and into each of the rows to bind one row from table with three columns Very welcomed feature should be selecting superior branches when user shows for ex ample branch Visual Web Pack in tree menu Netbeans user get hyperlinks to Netbeans Analogous when for example use
107. mponent diagram ll 73 xvil 10 3 10 4 10 5 10 6 10 7 11 1 11 2 11 3 11 4 11 5 B 1 B 2 B 3 B 4 B 5 B 6 B 7 B 8 B 9 C1 Page navigation diagram lt lt lt lt lt lt nn 74 Login activities scheme lt lt lt lt lt lt e 75 Diagram shows how is navigated branch page lt lt 76 Use Case of tutorial page ll rs 77 Graphical user interface partitioning most of pages 78 Code example createElearning method o 89 Code example encodeHeslo method o o o 90 Code example prerender method o 91 Code example logoutButton action method 91 Code example createButton_action method 92 Login page emu Eee A a dy 107 Hello page u 2 2 0 Be Se eS RESO e t Rm Ge bu een 108 Tutorial page x ccxc amp i tec Bee AAA A iu 108 PLAY DOPO dese ratto M t ge E E a e E eb znat d 109 User page 425 a scr pues E me tea AY ha a Ho A pde 109 Hlearn page asia a A cub er XO dres cu or O 110 Index page of vcjpa application lt lt lt lt 4 4 4 lt 110 List page of ve jpa application lt 2 lt lt lt lt 44 44 4 ee ee 111 New page of vc jpa application lt lt lt lt lt lt lt lt lt 4 4 4 4 111 The list of enclosed CDROM nn nn m nn 113 List of Tables Tel Java E components z A a Govt
108. n javax servlet Filter class is doFilter I m going to shortly explain which actions doFilter method performs 1 Examine the request header 2 Customize the request object 3 Customize the response object 4 Involve the next entity in the filter chain If current filter is the last in the chain next entity is the resource at the end of the chain If current filter is not the last one next entity is invoked according to configuration tags in DD Anyway it is very important to call doFilter method on the chain object If no doFilter method is called request will be blocked 5 When control returns from invoked doFilter method response headers are examined 6 When any problem during examination has been arisen exception is thrown Here is simple diagram showing how can be filter mapped in the DD including an appropriate XML configuration Figures 2 3 and 2 4 Filter2 rvl REQUEST gt i lt filter request i filter request i filter request E E chain doFilter E chain doFilter chain doFilter E E doMethod lt filter response gt lt filter response gt lt filter response RESPONSE lt Figure 2 3 Filter to Servlet Mapping 2 4 Constructing of responses Responses are represented as Java classes implementing the ServletResponse interface that provides many useful operation which Servlet can use during constructing responses I m goin
109. nabled To enable SSL in Java EE 5 web application security constraint have to be specified in application deployment descriptor web xm1 On Figure 6 2 is simple example how to make security con straint A user data constraint specifies a transport guarantee transport guarantee The choices for transport guarantee include following possibilities 35 Note that POST requests are in SSL communication deprecated 6 5 SPECIFYING A SECURITY CONSTRAINT 49 e CONFIDENTIAL Sends the data between the client and server in such a manner as to ensure that the true contents are unreadable e INTEGRAL Sends the data between the client and the server in such a manner as to ensure that the data are uneditable e NONE Requires no transport guarantees Authentication mechanism for web module should be in four modes Authentication mechanism is specified in auth method element in web xml e BASIC Uses basic authentication that is a user ID and password e DIGEST Uses basic authentication a user ID and password but sends the password in encrypted format e FORM Authenticates by presenting a Web Page for input Password is send in unen crypted format e CLIENT CERT Authenticates with a client certificate Basic authentication sends user ID and passwords over the Internet as text that is base64 encoded and the target server is not authenticated If someone can intercept the transmission
110. nform user about his identification eventually can perform some unique operations like e g accessing starting page from this block leftstd Left standard block The most of navigabilities in the application are divided into Left and Right standard block The main functionalities accessible from leftstd are ac cording to Figure 10 7 searching and navigating There is variety of possibilities how to access information that user actually wants to see Firstly he can use search engine At the time the searching is built on the knowledge of key value of the element which user want to actually see tutorial discuss Other way to access element which user is actually interested in is to use the navigation tree or a pregenerated list from the offer of best rated rightstd Right standard block Instead of leftstd the rightstd is partly customizable and makes the navigation really interested User can assign the most important elements according to his privileges into prepared checkboxes and then he can simply navigate them without the necessity of looking them repeatedly Naturally when user is logged out the customize settings are persistent Under these lists of favourites user can simply navigate to the tutorials he was discussed about them recently from my articles field in rightstd block Last in the rightstd is a place intended for printing system messages if some error in application occurs or some irreversible operation is perfor
111. ngle task or goal in following text doesn t contain details about stated use cases Notice that calling some user by Virtual Center invokes the external Skype application which has to be at the time already installed Remove tutorial Edit DB table u Add discuss Add tutorial Suspend tutorial doesn t irreversible delete tutorial from DB and remote storage as Remove tutorial Registered Cory aora Tutorial Registration skype Unregistered Add Remove favourites Figure 8 4 General Use Case 710 8 4 Chosen use cases in higher detail Users logged to the Virtual Center are able to perform several operations such as search or play tutorial login logout and etc as you can see on Figure 8 4 Following two diagrams Figure 8 5 and Figure 8 6 show some of referenced use cases in graphical form but more punctually and with some additional dependencies Use Cases contain only such use cases which should 60 CHAPTER 8 BASIC STUDY m Unregistered System First in order Email validation Input data type validation extend lt lt extend gt gt lt lt extend gt gt includ Username validation lt lt include gt gt Registration TE xu Input validation Find table Edit DB table incude mo gt Find editable field lt lt include gt gt Figure 8 5 Unregistered and Admin user in higher detail be finished within the scope of first
112. nology using the unified EL takes over the responsibility of evaluating the expression from the JSP engine and evaluates the expression at the appropriate time during the page life cycle JSP EL is designed only for immediate evaluation of expressions 3 9 JSP DOCUMENTS 23 Another problem is that JSF components need a way to invoke methods on server side objects during various stages of the life cycle in order to validate data and handle component events see Figure 4 2 on page 27 JSP functions are not sufficient because they can be used only for invoking static methods defined in a Tag Library Descriptor TLD file they cannot be used to dynamically invoke public methods on objects Unified EL was specified for all of these reasons From Table 3 2 is sure that standard and unified expression could be for developers useful and working with them is very effective 3 9 JSP Documents In short JSP document is JSP page written in XML syntax Such documents have all the benefits offered by the XML standard JSP documents have to be well formed Most of standard JSP syntax is already XML compliant with any exceptions Elements that are not compliant with their correct XML alternatives are collected in Table 3 3 XML syntax has new element root In general the root element is not obligatory in JSP but may become that it has to be used because of fulfilment XML compliant form of the whole document When we have in JSP two root elements non XML com
113. nt creates the pre master secret for the session encrypts it with the server s public key obtained from the server s certificate and then sends the encrypted secret to the server 5 Both the client and the server use the master secret to generate the session keys which are symmetric keys used to encrypt and decrypt information exchanged during the SSL session and to verify its data integrity 6 The client sends a message to the server informing it that future messages from the client will be encrypted with the session key In addition client sends a separate encrypted message indicating that the client portion of the handshake is finished 7 The server sends a message to the client informing it that future messages from the server will be encrypted with the session key It addition server sends a separate encrypted message indicating that the server portion of the handshake is finished 8 The SSL handshake is now complete and the session begins The client and the server use the session keys to encrypt and decrypt the data they send to each other and to validate its integrity 9 This is the normal operation condition of the secure channel At any time due to internal or external stimulus either automation or user intervention either side may renegotiate the connection in which case the process repeats itself 6 4 1 Java EE application with SSL With Sun Java System Application Server an SSL HTTPS connector by default e
114. ny new features which are not in JSP and it comes any duties for developers At first Pm going to say what are JSF applications composed from accordingly to that development team must implement particular components Following short list of components that must be implemented by developers Without that reader will be implemented by team of developers e JSF pages Exactly it means JSP pages created by using JSF tag libraries e Converters Validators Listeners and Backing Beans we will discuss how to create this custom components a bit later e Custom UI components and renderers will be discussed at the end of this chapter For common applications are not necessary e Configuration of application It means to configure navigation rules custom objects and sure creating DD 4 4 1 UI Components and the Component Tree UI Components are the basic reusable components for development of UI using the JSF Unlike Java Swing components JSF UlComponents are situated on the server side This fact leads to a major difference between UlComponents from standard desktop clients and web application user interface components The latter do not interact directly with the client so that every interaction between client and server requires a complete HTTP request response cycle Com pared to for example Java Swing user interface has JSF one big disadvantage When client inserts any input data for example into text input component there is no
115. of first Java Servlet technology version 1 was created by Sun Microsystems Inc in the middle of 1997 James Gosling known as the father of the Java programming language first thought about Servlets in the early days of Java but the concept did not become a product until Sun shipped the Java Web Server product 16 This was before what is now the Java Platform Enterprise Edition was made into a specification In the middle of 1990s dominated the domain of web applications CGI Common Gate way Interface Biggest drawback of CGI scripts was in bad designed life cycle For every request coming over the Internet to server had to be created new process This policy can work well only until server exhausts all the available memory Big problem with defensibility had arisen when internet community was growing up with staggering rate as in the second half of 90 s 2 1 Servlet vs CGI In contrast with CGI Java Servlets are handled by separate threads within the domain of server process It means that Java Servlets are also efficient and scalable Because Java Servlets run within the web server they can interact very closely with the server to do things that are not possible by CGI scripts 17 CGI based Web Server Java servlet based Web Server Main process Main process Request 4 P Process 1 Request 1 A o a Process 1 Request 2 IA 77 Process 2 Request 2 gt ay 2 Request 3 Process 3 Req
116. on private system Figure 8 3 Virtual Center requirements graphical User Interface Good usable and utility user interface support for standard users such as admin users Graphical interface for listing and editing data from database in tabular form There are other not just implemented features but planned into the future noticeboard with calendar e Learning course support open source and free software promotion 8 3 Use Case User roles on the Virtual Center are built on few separate privileges By default there will be set following rights e right to vote e rights for adding deleting discuss rights for adding deleting tutorials e rights for adding deleting users admin rights 8 4 CHOSEN USE CASES IN HIGHER DETAIL 59 According to assignment of these several rights to real users there are four types of users used in use case diagrams and distinguished by the Virtual Center obviously the number of possible user roles is 2 although some of them don t make sense vote discuss tutorials user mng admin unregistered false false false false false registered true true false false false vip true true true false false admin true true true true true Table 8 1 Table of active user roles Following General Use Case notice that Use Case with upper cases will stand for a whole diagram whereas use case is only one separate scenario for a si
117. on to support more than one lan guage and data format Localization is the process of adapting an internationalized application to support a specific region or locale Examples of locale dependent information are in addi tion to messages or user interface labels also character sets and encoding and date or currency formats All client user interfaces should be internationalized and localized In case of web application it is particularly important because of the global nature of the web Every appli cation with ambitions to be internationalized has to take internationalizing and localizing into account 8 2 SETTING SPECIFIC GOALS Age Attitude Personal goal Professional goal Friends Hobbys Family Major Computer skills Prefered communication method Motivation to use hi tech devices Travelling Planning trips Figure 8 2 8 2 Setting specific goals 87 introvert workaholic hair splitter go prosperous life to be reputable work all over the world with the up to date technology mainly from internet community Information technology internet security computers hardware lives on his own single sometimes attends parents software developer many programming languages tools for designing e mail conference SMS everybody else uses them happens after a lot of thinking and preparations allways Negative persona The Virtual Center is dedicated above all for sharing readable
118. on type description element is optional and contains description of persistence unit e jta data source element specifies global JNDI name of the JTA data source Trans actions will be managed by container Creating entity classes Entity class is JavaBean component including special Java Persistence annotations and repre sent a table in the database Entity class must implement Serializable interface Refer enced annotation elements are e Entity is the annotation for entity class e GIdisthe annotation for selection which property represents the primary key of the table e Table optional annotation to identify the name of the database table if it is different than the name of the Entity class 5 1 JAVA PERSISTENCE API 43 20 Entity 21 Table name animal 22 NamedQueries NamedQuery name Animal findByAnimalld 23 public class Animal implements Serializable 24 25 Id 26 Column name ald nullable false 27 private Integer ald 28 29 Column name aName nullable false 30 private String aName 31 32 Column name aDescription 33 private String aDescription 34 35 Figure 5 4 Persistence entity class example Entity class Animal on Figure 5 4 contains three private attributes ald aName and aDescription All these variables has in class own setter and getter methods In addi tion there are necessary imports of javax persistence x and java io Serializable packages bec
119. ons will discuss terms connected with ORM 39 40 CHAPTER 5 JAVAPERSISTENCE 5 1 1 Entities An entity typically represents a table in a relational database and each entity instance cor responds to a row in that table Persistent state of an entity is represented either through persistent fields or persistent properties All the field and properties within entity class use object relational mapping annotations to map the entities and entity relationships to the rela tional data in the underlying data store Bach entity must have one unique primary identifier Field which represent primary identifier is annotated by javax persistence Id Primary key can be according to Java Persistence specification simple or composed from more then one properties of entity class 5 1 1 1 Relationship multiplicities There are four multiplicities supported by Java Persistence One to one Each entity instance is related to single instance of another entity One to one relationship uses javax persistence OneToOne annotation on the corresponding persistent field For example one employer can be related with one office One to many Entity instance can be related to more then one instances of another en tity This multiplicity uses javax persistence OneToMany annotation An example could be customer who has more than single contact record Many to one When multiple entity instances can be related with one instance of another en tity property fiel
120. ontent Message queue is also accessible by FacesContext via getMessage method FacesContext can through method responseComplete terminate request pro cessing as soon as the current phase is completed This method is used if request was processed in the past and it is also not necessary to repeat it 4 4 3 Package javax faces render Render package includes main classes which makes from tree representation of UlComponents any HTML stream understandable for web client There are at least two good reasons why take interest in renders e we want to access JSF by different devices PDA PC text console e we want to create custom UlComponents so we have to implement renderers too What happens when the client device is a mobile phone or PDA that does not provide a HTML browser and therefore requires the web application to respond in another markup language 44 JSF DEVELOPMENT PROCESS 31 javax faces render RenderKit lt lt create gt gt RenderKit RenderKit addRenderer family String rendererType String renderer Renderer createResponseStream out OutputStream ResponseStream createResponseWriter writer Writer contentTypeList String characterEncoding String ResponseWriter getRenderer family String rendererType String Renderer getResponseStateManager ResponseStateManager Renderer lt lt create gt gt Renderer Renderer convertClien
121. pliant JSP we can simply change to compliant with wrapping all the text with the root like here lt jsp root version 2 0 gt lt our non XML compliant JSP gt lt jsp root gt Figure 3 2 Root element in JSP XML compliant document Syntax elements Standard Syntax XML Syntax Comments SS A lt 5 5 gt lt jsp declaration gt lt jsp declaration gt Scripting elements lt gt lt jsp expression gt lt jsp expression gt lt 5 5 gt lt jsp scriptlet gt lt jsp scriptlet gt 80 include gt lt jsp directive include gt Directives 0 page gt lt jsp directive page gt lt taglib gt lt jsp directive taglib gt lt lt gt gt EL Operator lt le gt ge l ne Table 3 3 Standard Syntax Versus XML Syntax 3 10 JavaServer Pages Standard Tag Library JSTL JavaServer Pages Standard Tag Library is set of tags managed by Sun Microsystems Inc and develop by the help of Java Community Process Main objective of JSTL is to provide a tool for for developers with the most frequently used actions by creating JSP pages Home page of JSTL project is http java sun com products jsp jstl JSTL is divided into four main groups of actions according to their functionality 1 Core with general functions such as conditions cycles iteration 3See 9 for more details about XML technology 24 CHAPTER 3 JAVASERVER PAGES TECHNOLOGY 2 XM
122. processes the request data sent by the client and selects the next view according to request parameters or state of the model Components of the view do not refer directly to each other Since the front controller Servlet is a single point of entry into the web application it may implement security and logging functions as well The view can be represented by any presentation technology like JSP or Servlet The model can be represented by JavaBeans or EJBs Enterprise JavaBeans This architecture is also called a centralized Very good information sources about architecture of Java applications are 14 24 request Instantiate I response Servlet Beans N Figure 1 4 Model 2 architecture of Java EE applications 1 3 Java EE Components Teams of developers create various components one of which can be for example instrumental to interaction between application and users another can be instrumental to achieve business logic and so on Whole application is composed of such Java EE Components It is possible to reuse functional components during development process and eliminate so production time Developer can these component naturally put up for sale too Java EE specification defines components shortly listed in Table 1 1 page 9 Note that JavaBeans components are not considered Java EE Components by the Java EE specification Java EE Clients Apparently from Figure 1 2 combine with Table 1 1 the
123. profile BLOB usersettings BLOB IndexName IndexType Columns PRIMARY PRIMARY user_id vc user FKIndex1 Index role id Appendix B Screenshots role user username jarda kortus password Registration Figure B 1 Login page 107 APPENDIX B SCREENSHOTS Virtual center for educators intutorials M Last added tutorials m e vB NetBeans 7 Profiler 7 Mobility 7 Visual Web Pack v E DB Designer nen ARES A TEM Lj 2 author jarda kortus key 4 author jarda kortus key 1 author jarda kortus key 3 O Query mode 30 11 2005 Short overview about02 11 2006 21 09 2006 creating dynamical web application in Meis visual way by Netbeans IDE plugin 7 Word wir Profitng Web applications A ae NetBeans code completion El author jarda kortus key 7 author helenka holikova key 8 author jarda kortus key 5 Netbeans plugin for13 08 2006 Netbeans plugin as12 08 2006 18 06 2006 profiling Java applications effective way for accessing the java class structure 1302007 Last in discuss with MS We Re Visual Studio 2005 Netbeans with integrated CVS 13 01 2007 loo Figure B 2 Hello page Virtual center for educators lastlogin 2007 01 14 10 57 40 NetBeans gt Visual Web Pack gt in tutorials Search tutorials e learnings Overview of Vis
124. r interface that makes work really fast Freemind is open source Home site of Freemind project is http freemind sourceforge net wiki index php Main _Page 68 CHAPTER 9 ANALYSIS 9 3 2 6 Inkscape For fundamental graphical design I used Inkscape Inkscape is very powerful multi platform vector graphic designer At work Inkscape is conformable to Adobe Illustrator or CorelDraw Inkscape 0 44 1 Some of diagrams in this thesis were made by Inkscape vector tool I used Inkscape version 0 44 1 available on the date 14 September 2006 The Inkscape s home site is http www inkscape org 9 3 2 7 Gimp For cropping images conversion into raster graphics format applying any image filters and other work with raster format I used Gimp application Gimp is free photo software for such E Gimp 2 2 11 tasks as photo retouching image composition and image authoring I used gimp only for very elemental working such as cropping images resizing compressing and similarly I used last available build on the date 27 August 2006 The home page of Gimp is http www gimp org 9 4 Server environment For my Virtual Center I needed some Application Server for running server side application There are numbers of good mostly free and open source Java Application Servers From the most popular servers I choose Java Sun Application Server because it is very good supported by Netbeans IDE and also it fully supports Java EE 5 standard
125. r on enclosed CDROM 12 2 Validation test According to designed acceptance test page 81 and requirements of the user a validation test over the functionality of VC was performed Table 12 1 gives a summary about alpha validation of VC including list of all elements that were tested and short notations about fulfilment of each element if passed or not 96 CHAPTER 12 TESTING AND INSTALLATION Create new registration Approve new user Un Suspend user Switch user roles Delete tutorial admin Delete tutorial user Login admin Login user Unsuspend tutorial Add new tutorial Add elearning course Delete Elearning course Create new discuss thread Remove discuss thread Reply existing discuss Add user tutorial to the favourites Remove user to the favourites button hyperlink Remove tutorial to the favourites button hyperlink Call user with skype Email to the user Search tutorial by id Search discuss by id Add registration request Navigate tutorial from the list of favourites SISISISISISISISISISISISISISISISISISISISISISISISIS Navigate user from the list of favourites Table 12 1 Summary of validation test results Part III Conclusion 97 98 Chapter 13 Conclusion This section concludes the thesis with
126. r would select 36SI3 user get sorted VUT gt FEL gt De partment of CSE gt 36513 where CVUT FEL and Department of CSE are active hyperlinks breadcrumbs for example Examples of GUI of Virtual Center like monitor screenshots are appended in Appendix B 10 4 Testing One of the main goals of this thesis is making robust secure application Firstly we have to say that it is nearly impossible to develop well tested absolutely bug free application in semi annual or annual sw project I know by experience that 50 80 of all the usability of functional bugs in application are discovered during first one or two years of active usage according to the type of project although the application was thoroughly tested before their release Because my technical knowledges about Java EE and used tools were on the start of this project very limited Java EE released in the middle of last year and Netbeans 5 5 together with VWP as late as last October and the documentations of both are very limited at the time the potential risk of nonexecution the project was very high I also have to design for the project such testing and project schedule which makes such risk as low as possible 10 4 1 Generally about test processing Main objective of tests I scheduled is to cover required application quality all over the devel opment process The developer who is responsible for testing in Java EE development team is tester These tests in this chapter are
127. re used when a component is only intended to work with a particular client device It allows to implement a component in one single class which results in an efficient and compact solution But this comes at the price of poor maintainability and reusability 2 Delegated rendering uses a separate renderers It delegates the work ofthe encode and decode methods to a renderer class This leads to the full separation of function ality and presentation parts and allows the use of different client types localization look amp feel and so forth When using delegating rendering switching between different clients is just a matter of replacing the RenderKit A renderer is derived from the abstract superclass javax faces render Renderer and implements the same methods a Ul component would use for direct rendering The renderer is a translator between the client and server side If a request is received the renderer performs the decoding This means that the renderer extracts the appropriate values from the request parameters and sets the UI component s values accordingly In other words the previous state of the component is reestablished When JSF is preparing to send a response back to the client the renderer performs the encoding through creating a representation of the component which the client is able to understand Most of information about rendering problematics in JSF 32 CHAPTER 4 JAVASERVER FACES pages I gathered from 25
128. release of Virtual Center Other functionality similarly referenced in section 8 2 and planned for following releases are not involved Notice that dependencies in Use Cases like include or extend stereotypes as well as some another elements should be represented by dash line instead of solid one The imprecise ness is caused by unsupporting dashed type of line by exporting in StarUML opensource UML utility when PDF output is set 8 5 Usability bounds setting The Virtual Center is no open system accessible by anyone Usability is bound on acquirement of valid user name and password Usually the registration process consists of creating registra tion request by a new user and sequent approving In such case admin receives all necessary details of requesting user via fulfilled registration request Depending on admin s decision new user account will be approved or not Anytime every user with privilege for user management can change user status change to suspended which means that from the time suspended user can t successfully login and use the application Application will recognize two independent GUIs The first one will be for every type of users whereas the second one will be accessible purely by admins and it is supposed for super vision of data tables in DB and checking up stored data This second GUT s not destined for common usage but recognition of possible database inconsistences or fault solving mechanisms Both GUIs will be impl
129. rends in e conference scope and e communities Before implementation of the application is necessary to be aware of purposes the application should serve for In this case Virtual Center will be service for educators To make best possible specification of the application I used personas theory to create primary Figure 8 1 secondary and negative personas Figure 8 2 representing real user of the application and one user for that the application is not designed Following several sections will be engaged with a number of requirements I have recog nized also through personas WANTED OG Age Attitude Personal goal Professional goal Friends Family Major Computer skills Prefered communication method Motivation to use hi tech devices Travelling Planning trips 47 extrovert polite patiet calm go happy life self pleased permanent job making career at university from university from sport from neighbourhood from internet community lives with his wife satisfied life has three adult children teacher project manager office software basic programming eyeball to eyeball phone skype no SMS make life easier safe time contact with friends and family from time to time official journey once a year holiday leave allways visiting cities over Europe Figure 8 1 Primary persona 55 56 CHAPTER 8 BASIC STUDY 8 1 1 Support for multimedia Today most of the
130. rn null Figure 11 1 Code example createElearning method Page navigation According to diagram on Figure 10 3 JSF supports two types of navigation Direct URL and indirect navigation rules in navigation configuration file When client is using cookies there is no problem with associating user with session because the session id is stored in the cookie When user client doesn t support cookies or want to disable them the application developer has to look for any alternative way Such possibility is sending session s id via each url request and response within the session When the direct navigation type url is used the developer has to ensure that every url was encoded by encodeURL method This method adds to the encoded url session s id JSF components call this method automatically but when some servlet or scriptlet in JSP is used encodeURL method has to be called explicitly When the indirect navigation type navigation rule is used the developer has to be very careful not to miss possible attributes sent by request bean object An original request is lost and a new one is created The only possibility how to traverse this is to use some superior scope to request like for example session scope The page navigation diagram you can see on Figure 10 3 on page 74 11 1 2 Login logout and data security All passwords of users are in the Virtual Center encrypted with MD5 algorithm I decided to implement my own MD5 algori
131. rom new user not approved Progress 1 Login with admin user Show all not approved registration requests Choose one user from the list Press approve button Try to login with new user OK New user is successfully logged in OK No not approved user in the list You have to create new registration request firstly Error System message about User approved was cought but the new user can t login since the system message about not approved is thrown Fatal error Approve operation was not performed Suggestion an error within the login method Error System message about A DataProviderException thrown is caught Con nection cann be established Approve action wasn t performed No suggestion oR UW Possible output Table 10 1 Registration request approving 10 5 ACCEPTANCE TEST Action User suspending Description Admin user can suspend any other user to disable his user account Suspended user ac count can be unsuspend again Only privileged users with admin or user management rights are able to perform this functionality Requirements e user account with admin or user management rights e user who should be suspended has to exist and mustn t to be already suspended Progress 1 Login with admin user 2 Show all users 3 Choose one user from the list 4 Press suspend button 5 Try to login with suspended user Possible
132. s foot notation The complete report which describes the same database scheme in text notation including data types of fields matching primary and foreign keys as well as obligation of some fields default values if set and other details is attached in Appendix A Thanks to the unified SQL language and Java Connector Architecture it is very conve nient to migrate to another database such as Oracle Firebird PostgreSQL or another when MySQL doesn t correspond with growing requirements in the future 10 2 Component design The whole Virtual Center consist of JSP pages that contain JSF components The architecture of components nor list of used components are interesting at the time I said that Visual Web Pack is as matter of fact a framework in itself Pll also describe structure of application how could be designed with this development tool Firstly we have to familiarize with chapters 1 2 3 and 4 from part I of this thesis Web client The Web client is represented by any supported web browser User via web client accesses the server According to web xml deployment descriptor start page is opened 71 72 CHAPTER 10 DESIGN ve discuss E 7 discuss id INTEGER parent id INTEGER FK SE user id INTEGER FK ne tutorial id INTEGER FK Pee Meee O e sic INTEGER AO Da 4 tutorial id INTEGER FK INTEGER 9 INTEGER FK parenting in discuss rate TINYINT e INTEGER
133. scription Simple user is not able to delete tutorials from the Virtual Center with tutorial rights he is able to suspend them Suspended tutorials are not visible for any simple users Admin users can delete or unsuspend any suspended tutorial for persistent delete or returning visibility to the tutorial Requirements e user account with vip rights e any existing unsuspended tutorial Progress 1 Find tutorial in Virtual Center 2 Remember tutorial id number in up right corner of tutorial detail form 3 Press gray Delete button on tutorial detail page 4 Try to find the deleted tutorial by known id from 2 Use search engine Possible output OK Tutorial is suspended As a result the tutorial details can t be accessed any more Error System message about Tutorial was suspended was catched but details of tutorial can be accessed Suggestion The Virtual Center ignores its invisibility or tutorial s suspended value wasn t changed Error System message about A DataProviderException thrown is caught Con nection with database can t be established The Virtual Center is consistent Try to find the tutorial again If you find him repeat the progress from 2 No suggestion Table 10 8 Tutorial suspending Action Tutorial unsuspending Description Suspended tutorial is visible only for admin user Admin user can such tutorial permanently delete or unsuspend to retrieve him vi
134. seld getPhaseld Phaseld A FacesEvent s s s l I i FacesEvent component UlComponent I getComponent UlComponent B A getPhaseld Phaseld lt lt interface gt gt lt lt interface gt gt isAppropriateListener listener FacesListener boolean ActionListener ValueChangeListener processListener listener FacesListener queue A 7 setPhaseld phaseld Phaseld processAction event ActionEvent processValueChange event ValueChangeEvent ActionEvent Phaseld lt lt create gt gt ActionEvent component UlComponent ActionEvent ANY_PHASE Phaseld isAppropriateListener listener FacesListener boolean APPLY REQUEST VALUES Phaseld processListener listener FacesListener INVOKE APPLICATION Phaseld PROCESS VALIDATIONS Phaseld RENDER RESPONSE Phaseld RESTORE VIEW Phaseld UPDATE MODEL VALUES Phaseld ValueChangeEvent VALUES List compareTo other Object int lt lt create gt gt ValueChangeEvent component UlComponent oldValue Object newValue Object ValueChangeEvent getOrdinal int getNewValue Object toString String getOldValue Object isAppropriateListener listener FacesListener boolean processListener listener FacesListener Figure 4 5 The javax faces event package 4 4 7 Validation Model Validation Model is JSF support mechanism for validatin
135. server side web applica tions it is new The event driven desktop model brings the development to a higher abstraction level removing the need to operate directly on level of the underlying stateless request response model of HTTP Therefore integration of the application logic is not more than assigning lis teners to UIComponents that generate events appropriate to the listeners Events represent user interactions with the UI and therefore provide the main mechanism for the UIComponents to propagate user actions Events are for example triggered by clicking a button or changing a value in some input field of the UI 44 JSF DEVELOPMENT PROCESS 33 The eventmodel of JSF is based on the eventmodel which is also the basis for the Java Swing GUI toolkit JSF technology supports three kinds of events e Value changed events e Action events e Data model events A value change event occurs when the user changes the value of a component represented by UlInput or one of its subclasses For example it should be done by selecting of any check box also an action which results in the component s value changing to true UlComponents which can generate these types of events are UIInput UISelectOne UlSelectMany and UlSelectBoolean components Value changed events are fired only when no validation er rors were detected Depending on the value of the immediate property can be these events processed in different phases of the JSF s life cycle Action
136. sfered over HTTP SSL Details about SSL connection was discussed in Section 6 4 Part II Virtual Center for Educators of Seniors 52 Chapter 7 Introduction While the previous chapters provided short introduction about Java EE technology this chapter moves on to concrete actual problem domain Because there are increasing numbers of seniors in the population all around the world it is very important to provide education for seniors to support their integration into the information society Virtual Center for Educators of Seniors is a web application which serves to support education of seniors all over the world Virtual Center represents an effective way to build an e community of educators of seniors and to share knowledges and best practices between members Main objectives of this part of thesis are to make specification to design and to imple ment test and deliver Virtual Center for Educators of Seniors 7 1 Skeleton plan The whole project can be divided into several cascading parts Some of these proceedings are very often concurrent or recursive as long as all the project members are satisfied I mean in this case for example two initial activities such as information retrieval and application designing There is one possible partitioning e Basic Study user profiling setting specific goals specifying of use cases and application usability bounds setting e Analysis other existing systems analysis
137. sibility for everyone Requirements e user account with admin rights e any suspended tutorial Progress 1 Find tutorial in list of suspended tutorials and navigate to its details 2 Remember tutorial id number in up right corner of tutorial detail form 3 Press gray Unsuspend button on tutorial detail page 4 Try to find the deleted tutorial by known id from 2 using search engine Possible output OK Tutorial was found details were displayed correctly Error No tutorial was found Error System message about A DataProviderException thrown is caught Con nection with database can t be established Tutorial is still suspended Try to repeat the whole progress Table 10 9 Tutorial unsuspending Action Adding new tutorial Description Every user with tutorial right admin or vip can create own tutorial and import them to the Virtual Center Requirements e user account with at least vip rights e existing tutorial in x shockwave flash data format Progress 1 Go to start page of the Virtual Center logged as user 2 Click the Add button in the top right corner of the middle layout 3 Fill the form and choose your data file with file chooser File mustn t be bigger then 30MB othercase the operation fails the value is adjustable by server adminis trator in web xml 4 Press the Store button 5 wait Possible output OK Tutorial detail page is displ
138. ssage The only supported file type at the time is x shockwave flash error message return null return tutorial Figure 11 5 Code example createButton_action method Chapter 12 Testing and installation This chapter is engaged with the final parts of the Virtual Center s development Installation and deploying of web applications are generally much more complicated then by a simple desktop application and so I ll try to describe the whole process with more details 12 1 Installation manual I will divide the whole installation process into separate concuring parts installation manual is punctually applicable only for the Virtual Center s installation on MS Windows XP If you are using a different operation system the installation process should also a bit different e Install JDK 5 if not already done 1 Run app jdk 1_5_0_06 windows i586 p exe from enclosed CDROM 2 Follow the installation wizard e Install SJSAS 9 if not already done 1 Run app sjsas_pe 9_0_01 windows exe from enclosed CDROM 2 Follow the installation wizard 3 Choose your password for accessing admin console e Install MySQL 5 if not already done BPO N HE Step by Manual Follow the installation wizard Run MySQL instance Config Wizard if not started automatically step choose Reconfigure Instance Detailed Configuration Developer Machine Multifunctional Dat Choose any path where you want
139. ssion session invalidate System out printIn Session was just invalidated follow redirect to login page return disconnect Figure 11 4 Code example logoutButton_action method e MySQL connectors version 5 and newer have problems in conjunctions with JPA Numbers of exceptions are thrown including an exception about Unable to retrieve EntityMan agerFactory 11 2 Unit tests designing and processing I used JUnit module in Netbeans for creating JUnit tests JUnit tests are automatically generated and the only task is to change todo part of each testing method JUnit tests use variables instance result and expResult Firstly an instance of the class is cre ated afterwards a tested method is performed and result is compared with expResult in assertEquals method which asserts that two objects are equal If they are not an AssertionFailedError is thrown Notice that I haven t try to use the newest MySQL Connector Net 5 0 3 GA from 04 January 2007 although according to the specification in release changes the bug 22425 wasn t fixed 92 CHAPTER 11 IMPLEMENTATION public String createButton_action UploadedFile uploadedFile fileUpload getUploadedFile String uploadedFileName uploadedFile getOriginalName int index uploadedFileName lastIndexOf String justFileName if index gt 0 justFileName uploadedFileName substring index 1 else Try backslash inde
140. t document 23 dl ISE View bier zn edet a a ea oe e etit a ete M ede 26 4 2 Statechart diagram of request processing life cycle 27 4 3 UI Component and UlComponent Base Classes 2 2 2 222 lt lt lt 30 4 4 Main classes from javax faces render package in UML 31 4 5 The javax faces event package lt lt lt lt 4 00 02 0004 34 4 6 Package javax faces validator e 35 4 7 Fraction from javax faces convert package 37 5 1 Object Relational Mapping sn 39 5 2 Entity Lifecycles 34 2 we iX EE Hot at cuis xeu 41 5 3 persistence xml example wa cen au be en ee cR RU dU 42 5 4 Persistence entity class example lt lt lt lt 44 44 ee 43 5 5 Simple query on animal table Emm nn 43 5 6 Using JTA transaction manager lt lt lt lt ee 44 6 1 Creating user in file realm by Admin Console lt 49 6 2 security constraint element in DD lt 4 50 8 1 Primary persona 55 8 2 Negative persona lt lt lt lt lt 4444 57 8 3 Virtual Center requirements lt lt lt lt lt lt lt a 58 8 4 General Use Case ee 59 8 5 Unregistered and Admin user in higher detail lr 60 8 6 Partition of Use Case for registered user lt lt lt lt lt lt lt lt 61 10 1 CE Remodel a Br ee d Ea eio ae hee eee 72 10 2 General Web application co
141. tails remove any discuss thread show author details Du AAA i nn M add tutorial to the user s favourites a registered read related discuss A C remove tutorial from user s favourites gt watch tutorial O unsuspend tutorial admin persistent remove tutorial Figure 10 6 Use Case of tutorial page 9 10 play This page is predeterminated for watching tutorials The only additional functionality for play page is an interface for voting tutorial User can vote from 1 to 5 where 5 is the best When user s vote will be entered user s view will be redirected to the tutorial detail page user Analogous with tutorial page user page shows details about selected user Naturally there is no possibility to play user in its place are contact user by skype or contact user by email client elearn Analogous with the tutorial or the user pages details about selected e learning course are selected by the elearn page At the time the only gathered details are according to the ER scheme Figure 10 1 title description or creation date Support for e learning courses is planned to be improved in the future but due to the Virtual Center doesn t want to supply systems that have to be already exist such functionality has to be very punctually analyzed before some revolutionary improvement would be performed in this direction 78 CHAPTER 10 DESIGN discuss The discuss page contains a simple form
142. te 12 January 2007 e The support for JPA in Netbeans Visual Web pack was very poor up to December 2006 Other side CachedRowSetXImpl usable from JDBC 3 0 is great alternative 11 2 UNIT TESTS DESIGNING AND PROCESSING 91 be ca r to it t will be require public void prerender if getUserProfile isLogged false getUserProfile isSuspended true info You are not logged in String theURL index jsp FacesContext faces FacesContext getCurrentInstance ExternalContext context faces getExternalContext HttpServletResponse response HttpServletResponse context getResponse try log redirecting response sendRedirect theURL log response lost faces responseComplete catch IOException ioex log IOEX ioex getMessage JK catch IllegalStateException isex log ISEX isex getMessage JK Figure 11 3 Code example prerender method public String logoutButton action ExternalContext econtext FacesContext getCurrentInstance getExternalContext Object session econtext getSession false SimpleDateFormat sdf new SimpleDateFormat yyyy MM dd hh mm log sdf format new Java util Date System currentTimeMillis username getUserProfile getUsername is removing old session if session null log usersettings backup getUserProfile persistentUserSettings HttpSe
143. ted into Java Servlet form and then services request in the same way as servlets did Here is the punctual list from JSP Life cycle behavior 1 If an instance of the JSP page s Servlet does not exist the container a Loads the JSP page s Servlet class b Instantiates an instance of the Servlet class c Initializes the Servlet instance by calling the jspInit method 2 The container invokes the jspService method passing request and response object By the first run the JSP page has to be converted into servlet class what is very lengthy and resource intensive process To eliminate such consumption of server s resources in the next time it is at first controlled in case the JSP page is older than appropriate Java Servlet class If not JSP page have to be converted anyway If Servlet is newer than JSP no conversion is needed and container uses the already created one JSP page is composed from standard HTML tags but including many special JSP tags In general JSP page can have two different forms The first form is very similar to HTML with numbers of new tags The second one is a XML compliant form and in this case the JSPs are called JSP Documents 14 3 2 Directives One of using elements in JSP pages are directives Directives are used to control how the web container translates and executes the JSP page Directives are in JSP specification three types page include and taglib By page directive written in defined syntax T
144. tener interface Servlets can register listeners for following life cycle events e Web Context Initialization e Web Context Destruction Web Context Attribute event added removed replaced e Session creation invalidation activation passivation timeout e Session attribute event same as previous e Request processing started e Request Attribute event All the listener classes must be specified in the DD Deployment descriptor 34 lt listener gt 35 lt listener class gt listeners ContextListener lt listener class gt 36 lt listener gt Figure 2 2 Semantics for inserting listener into DD Deployment Descriptor 2There are another not so freguently used reguest types see Section 2 2 2 on page 13 3Deployment Descriptor is XML configuration file for Web technologies in Java Web Applications 2 3 FILTERING REQUEST AND RESPONSES 13 2 2 1 Writing init method Developer can override the init method of Java Servlet to change its initialization be haviour Java Servlet which use Database connection can for example initialize this connection just here An unsuccessful initialization process throws UnavailableException 2 2 2 Writing doSomething Method HttpServlet interface provides several doMethods that start when the servlet is initialized and any user s request comes According to Java EE 5 specification Method is one of values Delete Get Head Options Post Put or Trace 14 Which method will be invoke
145. that were established before the project started there are many things enhancing both the conceptual and programmatical solutions provided in this thesis There are the most important improvement which could extend functionality and usability of VC whereas some of them were planned already in a frame of this project to the future but were not finished e Sharing of useful software utilities similarly like sharing tutorials e Support for other types of tutorials like movies static presentations e More customizations e g resizing of played tutorial e Author of thread or admin should be the only users able to delete discuss thread e Support to add new branch to the branche s tree dynamically e Progress bar during upload of a long file e Calendar of events Conferences Workshops Appendices 101 102 CHAPTER 13 CONCLUSION Appendix A Database report vc_tutorial ColumnName DataType PrimaryKey NotNull Flags Default Value Comment AutoInc tutorial id INTEGER PK NN UNSIGNED AI branch id INTEGER NN UNSIGNED user id INTEGER NN UNSIGNED create date DATE title VARCHAR 255 description VARCHAR 255 filepath VARCHAR 255 NN visited counter INTEGER UNSIGNED width INTEGER UNSIGNED height INTEGER UNSIGNED timelength VARCHAR 32 suspended BOOL demonstrator name VARCHAR 60 null demonstrator details VARCHAR 255 null IndexName IndexType Columns PRIMARY PRIMARY tutorial id vc tutorial FKIndex1 Index user id vc tu
146. the render response was Over any error error message will be displayed After the rendering of response current view is stored and so becomes available for next restore view phase 4 3 1 JSF life cycle scenarios In general web applications dont use only JSF pages Some of pages are static another are JSP without JSF components Rendering such web pages depend on type of request incoming from user s There are logical four scenarios may occur Faces Request on JSF content This is standard JSF scenario which is described on Fig ure 4 2 Non Faces Request on JSF content When user follows any hyperlink in static HTML page this scenario occurs Restore view phase creates new component tree and then skips directly to render response phase No event another user s input is possible because no active elements in user s request page Faces Request on non JSF content When user requests for an non JSF content e g static HTML page application will need to redirect to a different web application resource or generate a response that doesn t contain any JSF components by calling responseComplete from FacesContext object during apply request value phase of JSF life cycle Non Faces Request on non Faces content This case is not managed during JSF life cycle 44 JSF DEVELOPMENT PROCESS 29 4 4 JSF development process The development of JSF applications is a bit different with classic JSP applications JSF pro vides ma
147. the same as while the validation process fails Any calling renderResponse method will invoke skipping into render response phase If necessary to redirect to another web resource FacesContext responseComplete method can be called Events are in this phase broadcasted to appropriate listeners Phase 5 Invoking Application Component values have been converted and validated successfully all backing beans or model objects have assigned the up to date values of the components Because of this it is now safe to execute the applications business logic to handle form submissions Queued events are now broadcasted to interested listeners for example an event of a button that has been generated during the apply request values phase is now broadcasted Action listeners contain the business logic themselves or are delegating the execution to other objects Phase 6 Render Response This is the final phase of the request processing life cycle Since all request processing has been completed and the next view is displayed it is the responsibility of the current phase to render the next view to the client If this is initial request the components represented on the page will be added to the component tree as the JSP container executes the page Otherwise all the component are in the component tree already added so there is no reason add them again Components will render themselves as the JSP container traverses the tags in the page If way to
148. thm to become the same result as md5 function in SQL for MySQL The most important method from MD5Passwd class is encodeHeslo which is in the code example on Figure 11 2 Login page is encrypted according to the deployment descriptor configuration file DD password is also always dispatched in encrypted form and can t be misused by third party T here is a very important mechanism which forbids render 90 CHAPTER 11 IMPLEMENTATION public String encodeHeslo String heslo String method java security MessageDigest mdAlgorithm null try mdAlgorithm MessageDigest getInstance method catch NoSuchAlgorithmException ex ex printStackTrace if mdAlgorithm null mdAlgorithm update heslo getBytes 0 byte digest mdAlgorithm digest StringBuffer hexString new StringBuffer for int i 0 i lt digest length i heslo Integer toHexString 0xFF amp digest i if heslo length lt 2 heslo 0 heslo hexString append heslo return hexString toString return null Figure 11 2 Code example encodeHeslo method response phase if user is not logged in If user fakes for example the URL in web browser he is automatically redirected to the login page See Figure there is my own solution of redirecting in this case For logout mechanism I also need only to invalidate actual session objects to lose all information about user and new login is necessary
149. tics Multi Tier Architecture An enterprise application is separated across multiple tiers each tier manages one or more specific aspects of the application More details about ar chitecture of enterprise application will be discussed later in section about application architecture Multiple Users and Roles An enterprise application should support multiple users with multiple rights To achieve it we define firstly user roles with different privileges Every user having appropriate user role obtain the same privileges The behavior and appear ance of the application may differ depending on particular role and its privileges Confidential Information An enterprise application manages and works on confidential information not intended to be accessible for the public e g customer s private data fi nancial information or internal company knowledge Disclosure of this information rapidly leads to high costs and loss of reputation High Availability Requirements An enterprise application is often business critical and therefore has to endure heavy loads of requests Typically a repetitive short outages of the application results in significant financial and or reputation loss Security Constraint An enterprise application has typically strong requirements concern ing security This may include the need for authentication authorization and data in tegrity Access to enterprise applications is often not public but restricted
150. time goes on and I thing that in Java is future 9 3 TECHNOLOGY FRAMEWORKS 65 9 3 1 Frameworks From various of Java EE development frameworks I choose Java Server Faces because it is standard and I prefer standards instead of third parties From Java EE version 5 JSF is part of technology Another argument was MyFaces available components for free usage as well as AJAX Asynchronous JavaScript with XML components from Java BluePrint Project As well I though that Java Persistence API is the rightest way for accessing data from database Many arguments as insufficient support from Netbeans IDE or bugs in MySQL make this possibility only theoretical although very perspective to the future Notice that Netbeans 5 5 beta as well as 5 5 final release prefer for web application de velopment CachedRowSetXImpl and CachedRowSetDataProvider classes for accessing data in database and using of Java Persistence makes in this case of development very uncom fortable Netbeans inherited most of functionality from Sun Java Studio 2 known like popular Visual Web Pack feature module what did Netbeans to framework in itself 9 3 2 Tools All the used sw tools are open source what means that are free for use as same as for develop ment Usually exists also a community of developers and users what is often the only way to solve possible problems on development 9 3 2 1 Netbeans IDE The Netbeans IDE Integrated Development Environment is
151. tion Switching user roles Description Admin user or any user with user management roles can switch user roles for another users in VC Operation is reversible but only for privileged user Requirements e user account with admin or user management rights e any other user from Virtual Center Progress 1 Login with admin user 2 Show all users 3 Choose one user from the list 4 Choose from possible user roles and press Set button 5 Choose from the list of users the same user as in 3 6 Check actual user role Possible output OK Actual user role matches my selection Error Actual user role doesn t match to the value I ve chosen User role changing operation has not to be performed Suggestion an error in method which gather user role from the checkbox within the user page Error System message about A DataProviderException thrown is caught and printed Connection cannot be established Table 10 4 Switching user roles 83 84 CHAPTER 10 DESIGN Action Tutorial deleting Description Admin users can delete any tutorial regardless of suspended value Tutorial file is removed from specified storage as well the tutorial record is removed from database All related discuss for this tutorial is also removed from database according to cascade delete set in MySQL Requirements e user account with admin rights e any existing tutorial Progress 1 Find tutorial in list of suspended t
152. tld context FacesContext clientld String String decode context FacesContext component UlComponent encodeBegin context FacesContext component UlComponent encodeChildren context FacesContext component UlComponent encodeEnd context FacesContext component UlComponent getConveredValue context FacesContext component UlComponent submittedValue getRendersChildren Figure 4 4 Main classes from javax faces render package in UML It is also problematic to add support for a different client device later on It would require a large number of changes within the web application JSF provides a better solution Renderer is separate part of JSF application which has nothing to do with component functionality A renderer produces the output for one specific UICcomponent which is associated with A set of renderers is organized into a RenderKit A RenderKit is derived from the abstract superclass javax faces render RenderKit shown in Figure 4 4 The rendering model of JSF describes two methods of component rendering 1 Direct rendering encapsulates the rendering logic directly into components so there is no clear separation of functionality and presentation To implement direct rendering of a component the component has to override the encodeBegin encodeChildren encodeEnd and decode methods to produce the response to the client itself and handle the data received from the client These methods a
153. to use by them special designed classes JavaBeans or include output from another pages into actual page via standard tags More about standard tags you can find in 15 or 22 Custom tags use prefixies defined by taglib directive and serve for using tag libraries defined by developers 22 CHAPTER 3 JAVASERVER PAGES TECHNOLOGY 3 6 Sharing objects JSP knows four types of scope objects request page session and application These objects are created by container and serves for creating dynamic content Encapsulation of application s behaviour into objects makes possible for developer to focus on presentation issues It holds generally not only for scope objects but for example JavaBeans components For scope objects there exist isThreadSafe parameter in page directive see in Table 3 1 which can specify how will container access to such resources Default setting is true and it is the only recommended value because otherwise this attribute is converted into SingleThreadModel which is from Java Servlet 2 3 deprecated 3 7 JavaBeans Components JavaBeans components are Java classes which can be easily reused and composed together into applications JavaBeans components have to contain appropriate get Property methods for every readable property that returns value of readable property and set Property methods for writing value into appropriate writable property within the JavaBean component similarly with scope objects In addition J
154. to well defined groups of users like employees business partners or customers I will discuss about secu rity questions in the Section 6 a bit later 1 2 Application Architecture Java EE platform uses a distributed multi tiered application model for enterprise applications Application logic is divided into the separate tires For better imagination how tiers cooperate together look on the Figure 1 2 on page 7 Logical tiers in Java EE are follows e Client Tier running on the client machine e Web Tier running on the Java EE server 1 2 APPLICATION ARCHITECTURE 7 Client Machine Java Application Server Database Server Figure 1 2 Multi tiered Application e Business Tier running on the Java EE server e EIS Tier Enterprise Information System Tier Software component running on the EIS Server Although Java EE applications should consist of four tiers shown in the Figure 1 2 most of the Java EE multi tiered consist only of three tiers Very important idea using in Java EE is building applications from components 1 2 1 Model View Controller The MVC Model View Controller architecture which has its background in the Smalltalk environment provides design patterns for developing GUIs Graphical User Interfaces Ap plication of this architecture leads to a strict separation of the following components model represents the business logic part of the application A cl
155. torial FKIndex3 Index branch id vc interest ColumnName DataType PrimaryKey NotNull Flags Default Value Comment AutoInc user id INTEGER PK NN UNSIGNED branch id INTEGER PK NN UNSIGNED details VARCHAR 255 IndexName IndexType Columns PRIMARY PRIMARY user id branch id vc user has vc branch FKIndexi Index user id vc user has vc branch FKIndex2 Index branch id vc user role ColumnName DataType PrimaryKey NotNull Flags Default Value Comment AutoInc role id INTEGER PK NN UNSIGNED AI admin BOOL NN tutorial BOOL NN discuss BOOL NN voting BOOL NN user manage BOOL NN name VARCHAR 45 NN description VARCHAR 255 IndexName IndexType Columns PRIMARY PRIMARY role id 103 104 APPENDIX A DATABASE REPORT vc_tut_vote ColumnName DataType PrimaryKey NotNull Flags Default Value Comment AutoInc user id INTEGER PK NN UNSIGNED tutorial id INTEGER PK NN UNSIGNED rate TINYINT UNSIGNED create datetime DATETIME IndexName IndexType Columns PRIMARY PRIMARY user id tutorial id vc tut vote FKIndex1 Index user id vc tut vote FKIndex2 Index tutorial id vc language knowledge ColumnName DataType PrimaryKey NotNull Flags Default Value Comment AutoInc language id INTEGER PK NN UNSIGNED user id INTEGER PK NN UNSIGNED IndexName IndexType Columns PRIMARY PRIMARY language id user id vc user has language FKIndexi Index user id vc language knowledge FKIndex2 Index language id vc language ColumnName DataType PrimaryKey NotNull Flags Default Valu
156. toring code com pletion many refactoring features macros recording customizable shortcuts and much more e Netbeans Visual Web Pack for creating graphical designing of web application New support for UML in Netbeans 5 5 Enterprise Pack Integrated solution providing information about runtime behavior of the application calls Netbeans Profiler e For more information about Netbeans Features Addons or for example for seeing many Netbeans tutorials and demos visit home site of Netbeans 26 9 3 2 2 CVSNT Server CVSNT is server side software used to keep a track of changes to files stored on a com puter I used last available version on the date 27 August 2006 version 2 5 03 2382 Client application can be simply Netbeans IDE with installed CVS Versioning System module ver sion 1 7 22 1 42 1 under Version Control The home site of the project is http www march hare com cvspro tfree SUML Unified Modeling Language is in software engineering graphical language for visualization specifica tion planing and documentation of development any system More information about UML you can find in 27 9 3 TECHNOLOGY FRAMEWORKS 67 9 3 2 3 StarUML StarUML is an open source project to develop fast flexible extensible featureful and freely available UML modeling tool StarUML supports directly UML 2 0 standard All the UML diagrams such as activity or process diagrams as well as case study from this thesis were made by St
157. tring VALIDATOR ID String lt lt create gt gt DoubleRangeValidator DoubleRangeValidator lt lt create gt gt DoubleRangeValidator maximum double DoubleRangeValidator lt lt create gt gt DoubleRangeValidator maximum double minumum double DoubleRangeValidator equals otherObj Object boolean getMaximum double getMinimum double hashCode int isTransient boolean restoreState context FacesContext state Object saveState context FacesContext Object setMaximum maximum double setMinimum minimum double setTransient transientValue boolean validate context FacesContext component UlComponent value Object Figure 4 6 Package javax faces validator is to implement Validator interface that performs the validation process Developer has to implement constructor method a set of accessors methods for any attributes on the tag and a validate method which overrides the validate method of the Validator interface After implementing Validator interface it remains to register the validator implementation in the application and to create custom tag or use validator tag to register validator on the component Other possibility is to delegate the validation to a method of a JavaBeans through a method binding expression Validation is processed during validation phase of the JSF life cycle When any validator checking fails an exception is thrown and UlComponent
158. ual Web Pack v NetBeans El pr M PI ize a 7 Mobility Resolution 721x428 y 7 Visual Web Pack Presentation length 8min DES ES Description Short overview about creating dynamical web application in visual way Add to favourites v B DB Designer by Netbeans IDE plugin VWP Exclude from ieu to Design mode 7 Query mode v Microsoft Office Word i D Discuss Bos D p Menu re re re JPA in VWP Helena Holikova 14 01 2007 05 41 56 Top rated tutorials 1 answer delete s with integrated re re JPA in VWP Jarda Kortus 14 01 2007 05 41 24 en Is it planned to the future eet dein re JPA in VAP Helena Holikova 14 01 2007 05 40 40 At the time not answer delete JPA in VAP Jarda Kortus 14 01 2007 05 40 19 ls it possible to use JAP together with Netbeans VWP Thanks answer delete IDE 13 21 2007 d Uu Starting with MS Word tor seniors 13 01 2007 Figure B 3 Tutorial page username helenka holikova lastlogin 2007 01 13 16 21 23 favorite tutorials NetBeans Mobility v favorite users 109 com test QueueTest mergeEvents jsvs uti List 8160 ms 30 2 com test QueueTest fullFill java util List int 482 ms 5 2 Configuration Eam Entire Application leom test QueueTestsEvent cinit gt com test Queer Status Running com test QueueTestremoveEvents java util List Profiling Results com test QueueTest test uy org apache n
159. ublic key encryption however 48 CHAPTER 6 JAVA EE SECURITY public key encryption provides better authentication techniques An SSL session always begins with an exchange of messages called the SSL handshake The handshake allows the server to authenticate itself to the client by using public key techniques and then allows the client and the server to cooperate in the creation of symmetric keys used for rapid encryption decryption and tamper detection during the session that follows Optionally the handshake also allows the client to authenticate itself to the server Simple description of SSL handshake follows 1 The client sends to the server the client s SSL version number cipher settings session specific data and other information that the server needs to communicate with the client over SSL 2 The server sends to the client the server s SSL version number cipher settings session specific data and other information that the client needs to communicate with the server over SSL The server also sends its own certificate including servers public key 3 The client uses the information received from server to authenticate the server If the server cannot be authenticated the user is warned of the problem and informed that an encrypted and authenticated connection cannot be established If the server can be successfully authenticated the client proceeds to step 4 4 Using all data generated in the handshake thus far the clie
160. uest 3 E Figure 2 1 CGI script vs Java Servlet life cycle TReguests needn t to come over Internet LAN or another way such as local access is possible 11 12 CHAPTER 2 JAVA SERVLETS 2 2 Servlets life cycle In the memory there is the only instance of the servlet and for every request a new thread is created by container Developer can change the model by implementing SingleThreadModel interface but this interface is from Java Servlet 2 3 deprecated and so I ll not take this case into account Servlet stays in the memory after terminating the request thus other request even other servlets can share such data Life cycle of the servlet has three steps 1 If an instance of the Java Servlet does not exist the Web Container a Loads the servlet s class b Creates an instance of the servlet class c Initializes the servlet instance by calling the init method 2 Passing request and response objects By every users request a Creating new servlet s thread b Invoking the service method the method firstly detects type of the request GET POST and then calls method doGet or doPost 3 Finalizing the servlet By long time inactivity or administrator s decision a Optional polite notify about the intention b Invokes destroy method Developers can monitor servlet s life cycle events by creating special listener objects Such listeners have to implement HttpSessionLis
161. unit which will be used or can generated the new one All entities will be created Very good tutorial how to use NetBeans for database connection in Java EE applications can be find in 30 The Virtual Center application discussed in second part of this thesis is not implemented using JPA Visual Web Pack module a new Netbeans module for Java EE web application development is determined to use CachedRowSetXImpl classes for accessing database The thesis contain enclosed application vc_JPA that doesn t use UI component and wasn t developed in VWP vc_JPA application you can find in vc_JPA enclosed CDROM Chapter 6 Java EE Security Security of application is today one of the most important guestions associated with web ap plication development Possible outflow of sensitive data from developed application to the prejudice of third party could cause big monetary costs but above all irreversible lost of repu tation too This chapter will discuss how to make application as secure as possible with Java EE 5 technology This chapter will not discuss about the failure of human element but purely about Java EE security technology question of security of any Java EE application Some areas of security depend on used application server and can be a bit different by using another application server then Sun Java Application Server PE 9 At first I list a few basic terms associated with security Authentication The means by which communi
162. ure 10 4 is shown mechanism of login the primary way for accessing the page if not https request user is redirected to https port http s request validation wrong loading login page lt reload login Input validation oo reset form lt lt user gt gt E username lt lt lt DB gt gt lt lt user gt gt users password Authentication depending on what login auth successful type is selected Navigation to start page O auth wrong Auth failed page Figure 10 4 Login activities scheme admin Analogous to hello page for basic user admin user has admin page Administrator can use ad vanced functionality not allowed for basic user like user management persistent delete tutorials or another branch Branch form page is predeterminated for showing tutorials related to selected branch Na vigation to the page can be alternative First possibility is the typical JSF navigation by configuration file navigation xml Because there is not possibility to send information about selected branch via this type of navigation this information has to be stored within some shared object In my case Pll use SessionBean object because there could arise some problems when using RequestBean Punctual reasons will be trashed out in following chapter of this thesis The second possibility is navigation via url hyperlink including id p
163. utorials or alternatively and navigate to its details 2 Remember tutorial id number in up right corner of tutorial detail form 3 Press red delete button on tutorial detail page 4 Try to find the deleted tutorial by known id from 2 using search engine Possible output OK Tutorial cannot be found Error You have found deleted tutorial Details are displayed and tutorial file size is valid number Error You have found deleted tutorial Details are displayed but tutorial s file size is file not found Tutorial was deleted from local storage but removing tutorial record from database was unsuccessful Error System message about a DataProviderException thrown is caught Con nection with database can t be established Tutorial is probably deleted from local storage this operation precedes deleting from database Error System message about Tutorial can t be deleted from local storage is caught An IOException thrown during deleting tutorial Tutorial wasn t deleted from local storage nor from database May be that tutorial is in use at the time when deleting Table 10 5 Tutorial deleting Action Login admin Description Admin and basic users have both a bit different graphical user interface to improve usability of the application Requirements e user account with admin rights Progress 1 Navigate to login page Possible output 2 Switch combo
164. veloped application Virtual Center for educators of seniors is a web application using database access Users will use thin clients via Web browsers as well as administrator Today there are face to face two strongest technologies Java EE 5 earlier J2EE and NET I choose Java Enterprise Technology in version 5 and I ll try to explain my greatest reasons 1 2 10 11 Java EE is being marketed by an entire industry Java EE is a proven platform with a few new web services APIs Notice that NET has quite new reporting services t00 Only J2EE lets you deploy web services today Existing J2EE code will translate into a J2EE web services system without major rewrites Not true for Windows DNA code ported to NET Java EE is a more advanced programming model appropriate for well trained developers who want to build more advanced object models and take advantage of performance features Java EE gives platform independence Java EE lets me use any preferred operating system such as Windows UNIX or main frame Developers can use the environment they are most productive in Java EE lets me use Java which is better than C due to market share and maturity There are 2 5 million Java developers IDC predicts this will grow to 4 million by 2003 78 universities teach Java and 50 of universities require Java Netbeans Open and wide Java community Java EE begins to dominate more and more as
165. verter lt lt create gt gt EnumConverter targetClass Class EnumConverter isTransient boolean restoreState facesContext FacesContext object Object 141100000 IntegerConverter saveState context FacesContext Object setTransient transientFlag boolean SSS SY ae DoubleConverter CharacterConverter lt lt interface gt gt Converter LongConverter getAsObject context FacesContext component UlComponent value String Object getAsString context FacesContext component UlComponent value String String ByteConverter LongConverter DateTimeConverter CONVERTER ID FloatConverter DATE_ID DATETIME_ID NE STRING_ID BigDecimalConverter TIME_ID i lt lt create gt gt DateTimeConverter DateTimeConverter getAsObject context FacesContext component UlComponent value String Object getAsString context FacesContext component UlComponent value String String getDateStyle String getLocale Locale getPattern String getTimeStyle String getTimeZone TimeZone getType String isTransient boolean restoreState context FacesContext state Object saveState context FacesContext Object setDateStyle dateStyle String setLocale locale Locale setPattern pattern String setTimeStyle timeStyle String setTimeZone timeZome
166. w Entity Entity created by using new keyword New Entity doesn t have persistent representation e Managed Entity Entity having persistent identity and associated with persistence context 5 1 JAVA PERSISTENCE API 41 e Detached Entity Detached Entity has persistent identity but it is no longer associated with an persistence context e Removed Entity Has persistence identity at the moment is associated with persistence context but is scheduled for removing from database Detached entity Removed entity Figure 5 2 Entity Lifecycle Entity Listeners Entity listeners or callback method are designated to receive invocations from persistence provider at various stages of entity lifecycle Callback methods annotate callback handling methods right in the entity class or put them in a separate listener class Each event has designed appropriate annotation e PrePersist or PostPersist PrePersist or PostPersist annotation marks an en tity s method as a callback before or after a new entity is created in the database e PreRemove or PostRemove PreRemove or PostRemove annotation marks an entity s method as a callback before or after an entity is deleted from the database e PreUpdate or PostUpdate PreUpdate or PostUpdate annotation marks an entity s method as a callback before or after updates to an entity are saved to the database e PostLoad PostLoad annotation marks an entity s method as a callback after
167. way to validate data at client machine because all the application logic is stored in program on the server machine It means that data must be sent over HTTP to the server which validate them and answers response Such communicate calls request response cycle JSF UlComponents are compoundable while the composition of components forms a component tree A component tree or a view is JSF s internal representation of a page The relations between nested components are a parent child relationship For example a form component as the parent contains several textField components and labels as children The JSF specification defines another kind of relationship between components called facet too A facet is a subordinate component that has a named relationship and a specific role according to the superordinate component The relationship is independent of the usual parent child relationship For example a table has a facet relationship to header and footer while the rows of the table are the child components associated to the table The UI component itself defines only its functionality The appearance to the user is created by a renderer Therefore this architecture separates the functionality from the presen tation which allows a flexible handling of different client devices PC PDA Mobile All user interface components are derived from the base class UIComponent which defines methods for the navigation in the component tree int
168. with two text fields or text areas supposed for inserting title and body of actually creating new discuss thread The only additional data necessary for creating new discuss are author s id and parent discuss for creating relationship between parent and child in discuss table hierarchy The author s id is already stored in the session scope because he is actually successfully logged and all the information about them are also available in special session scope Id of the parent discuss is conveyed in the same way as by accessing branch or another pages tnew The tnew form is supposed for inserting new tutorials to the virtual center One swf file mustn t to be bigger then 30MB otherwise the creating tutorial will be unsuccessful application setting 10 3 Graphical user interface Usability and graphical user design are together the most important issues in software appli cation development The Virtual Center is implemented to provide many user friend features such as customization quick access to the most frequently or best rated elements etc topstd leftstd rightstd search about me navigation tree my favourites other favourites my articles tops partners system messages Figure 10 7 Graphical user interface partitioning most of pages Very good practices for building good navigable and ergonomic graphical user interface und
169. with unlimited access all over the application s components and functionalities Admin account can also create new admins or another types of users Testing consistence of the database will be provided by set of SQL scripts which will produce tables of data and possible inconsistence In the application will be put emphasis on the security of the web application too The greatest part of acceptance tests will be apply to presentation logic and business logic of the application if the application does in the appropriate way what user expect 10 5 2 Documentation requirements Integral part of the application is the necessary documentation It consist of these separate parts e Install and uninstall user manuals digital form e Technical documentation for the application Part II from this thesis e Source codes digital form 10 5 3 Functionality requirements Functionality is depending on the user role of the signed in user A collective requirements for all tested cases are e web browser supporting HTTP over SSL e internet LAN connectivity or installed Virtual Center on local machine Action Registration request approving Description Admin user or any other user with user management right can approve registration request to enable user account Without this action new user can t use the Virtual Center application Requirements e user account with admin or user management rights e submitted registration request f
170. without always being connected to its data source Further it is a JavaBeans component and is scrollable updateable and serializable 37 DB server MySQL Well documented open source database server page 69 Web client Glassfish server 9 01 lt lt artifact gt gt lt lt artifact gt gt JSP D web xml L1 JavaBeans compiled when firstly needed Servlet AAA SessionBean lt lt artifact gt gt managed beans xml ApplicationBean PageBean i C JDBC3 0 lt CachedRowSet 1 DB server MySQL C C RequestBean Figure 10 2 General Web application component diagram 10 2 1 Page structure This section describes page structure and simple navigation over the Virtual Center Figure 10 3 Diagram shows only actual planned functionality When new page is added no changes 74 CHAPTER 10 DESIGN are needed developer only append some necessary navigation rules especially disconnect for example tutorial disconnect tutorial Euser E Be hello amp L B Q m user Pe playjsp disconnect a tutorial branch jsp 3 Ej VERA TER ER 4 3 admin jsp i FA Sm P y i i Si tutorial amp amp amp i Si disconnect ge E Si admin Sez S admin a E user
171. x uploadedFileName lastIndexof if index gt 0 justFileName uploadedFileName substring index 1 else No forward or back slashes justFileName uploadedFileName String uploadedFileType uploadedFile getContentType int lastdot justFileName lastIndexOf String prefix new String new SimpleDateFormat yyMMdd format new Date System currentTimeMillis String message new String if uploadedFileType equals application x shockwave flash CachedRowSetDataProvider tutorialDP new CachedRowSetDataProvider try ServletContext theApplicationsServletContext ServletContext this getExternalContext getContext String realPath theApplicationsServletContext getRealPath data swf int counter 0 File file new File realPath File separatorChar prefix justFileName while file exists true file new File realPath File separatorChar prefix _ counter _ justFileName message new tutorial was created was created uploadedFile write file try there is a set of commands creating new row into vc_tutorial catch DataProviderException ex ex printStackTrace catch Exception ex message new String Cannot upload file justFileName An ex getMessage 0 return null finally release resources tutorialDP close else not possible to upload not swf file me
172. y some bug in the method saving the e learning Error System message about A DataProviderException thrown is caught Con nection with database can t be established E learning course information are not stored in the Virtual Center Table 10 11 Adding e learning course Action Deleting information about e learning course Description Every user with at least vip rights can delete information about existing e learning courses that he stored earlier Requirements e user account with at least vip rights Progress 1 From leftstd gt e learnings gt some branch choose any e learning that actually logged user created 2 Press Delete button on the top of the page 3 Navigate to the e learnings and choose the same branch as last time Possible output OK On the page is list of e learnings if any related to the selected branch and your e learning is not in the list Your e learning course was removed from the Virtual Center Error The e learning you have deleted recently is still in the list Suggestion There is probably some bug in the method deleting the e learning Error System message about A DataProviderException thrown is caught Con nection with database can t be established E learning course information weren t deleted Table 10 12 Deleting information about e learning course

Virtual Center for Educators of Seniors Jaroslav Kortus

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