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MASTER THESIS

1. There is a need of distinguishing user s records from all public records in experiments and scenarios sections therefore these activities dispose of tabs in navigation menu When selecting a tab related fragment replaces body of an activity Each fragment has its own array adapter so fetched data are independent across fragments When selecting an item from fragment s list view details of the specific record are displayed Information is displayed either in its fragment which applies to tablets or in a separate activity phones This behaviour was chosen in order to preserve amount of displayed information on screen while keeping layout clear and readable The application chooses which way to display data upon fragment s creation when it retrieves a layout resource If there is a details frame in the layout the data are displayed 98 Chapter 15 Client Side V EEG Base for Android Specifics inside this frame otherwise a details activity is created Details class naming convention in this application is lt Type gt Details lt Activity Fragment gt e g ExperimentDetailsFragment The only issue in displaying details is with a collection of records which we need to display in scrollable component In such case we cannot use another listview or a similar scrollable component but we must create a frame layout into which we programmatically create and inflate row items one by one Such solution may be seen in ExperimentDetailLi
2. Characters left 238 Upload file ZCUrootCA der j Select file SA Upload file Figure D 7 Experiment data file upload Another section of the application is a Reservation section In it user may select a date using Choose data button and then fetch records to such date from the server either by tapping the empty list body or by clicking the Refresh button There are details which can be displayed by selecting a specific record as well as in Experiments or Scenarios and there can be created a new record in activity under the Create reservation button Figure D 8a Unlike in other sections reservations can be removed if they belong to the user or the user has administrator rights in the EEG Base Such record removal is performed by clicking on the X button in the record list item and the following dialog must be confirmed Figure D 8b 88 Appendix D EEG Base for Android User Manual Reservations 27 04 2013 Choose date Reservations A Are you sure you want to remove this reservation a Reservations overview with fetched removable record b Removing reservation record Figure D 8 Reservations The last section of the application is Settings Figure D 9 User can change the EEG Base credentials or service URL here Unlike login screen there is important to keep rest URL suffix which was not present in log in There is also a possibility to set Monday as a first day of week which might be useful for u
3. Java based applications it is fairly simple to write an application Documentation many tutorials are available on Android Developers web as well as common JavaDoc documentation Community There are numerous forums dedicated to Android Open source with support from Google While Android is developed as an open source platform Google organizes developers meet ups and even maintains a YouTube channel dedicated to development on Android Android Developers 7 1 6 40 00 O do 29 30 n o 25 0096 20 00 15 00 10 00 i 4 00 5 00 1 70 0 ni 0 10 Emm 0 2096 NS AN y gt s y VA x aD L V amp 9 o D w S o v SS S lt gt o d oO o N N amp e v gS SS Ss x S Q o S e EX o Nd Figure 7 1 Android OS versions market share in April 4th 2013 21 8 Android Specifics 8 1 Resource Handling The Android platform has a specific way of resolving resources in matter of which one will be used The resources are separated into different resource directories by their purpose The list of basic resource directories and their contents is following 11 e animator XML files of property animations 10 e anim XML files of tween animations 13 e color specific colour behaviour for assigned view components e drawable pictures e layout layout definitions e menu options context sub menu definitions e raw files which are accessed using str
4. DVD 39 12 Client side 11 Working with Data 12 1 SharedPreferences Storing User Data In many applications there is a need of storing basic information like username or password While such information might be stored in a database we do not need a database at all The Shared Preferences are useful way to store such information without implementing additional logic which is required for working with database In our application we use Shared Preferences for aforementioned storing of credentials and information required to connecting to the server There may be multiple Shared Preferences which are distinguished by a string identifier name and can be accessed with different modes of Android context through which the Preferences are available The obtained SharedPreferences are a decorated Map with own Editor used for changing its content and with a change listener used for an automatic update of dependent components 12 2 ListView and Complex Data Types Android provides a basic set of View elements which can be used They can be both created and manipulated in a source code and defined in layout XML and accessed in a code afterwards 8 But what happens if default component s behaviour does not provide functionality we require Sometimes it is needed to write own component but often there is a simpler way A ListView is the most common representative of such components When we have data in collection we would like to di
5. would take you back to the list view of records In order to use home button you must edit behaviour of the ActionBar in activity s on Create method as in Listing 11 0verride public void onCreate Bundle savedInstanceState super onCreate savedInstanceState getActionBar setDisplayHomeAsUpEnabled true J Listing 11 Turning icon into Home Up button 14 1 2 Fragments The situation is a bit different in fragments implementation since an activity is superior to a fragment Fragments have no options menu by default so we must inform a parent activity that our fragment provides it It is performed in the fragment s onCreate method by passing a true value to setHasOptionsMenu method Menultem events are handled in the same way as in activities but do not forget to invoke a super method since the event must be passed to an activity if the menu item identifier was not recognized Inflating menu is also a bit different from the approach used in activities The onCreateOptionsMenu method already provides a menu inflater instance as well the menu instance itself so the only thing necessary is to inflate a menu resource and to invoke the super method 48 Chapter 14 Client side IV Navigation 14 2 Tabs Navigation Tabs are one of the most common navigation elements in Android applications They are used to separate content by their categories and to make orientation easier The tabs are a part of an ActionBar and
6. 25 26 27 28 Appendix A JAXB Annotations Example package logic import data ScenarioSimpleData import javax xml bind import java io File public class Writer 1 public static void main String args ScenarioSimpleData scenario new ScenarioSimpleData scenario scenariold 12 scenario scenarioName Test JAXB scenario try File file new File scenario xml JAXBContext context JAXBContext newInstance ScenarioSimpleData class Marshaller marshaller context createMarshaller output pretty printed marshaller setProperty Marshaller JAXB FORMATTED OUTPUT Boolean TRUE marshaller marshal scenario System out marshaller marshal scenario file catch JAXBException e e printStackTrace Listing 17 Writer java Output stored in scenario xml is the following scenario lt scenarioId gt 12 lt scenarioId gt lt scenarioName gt Test JAXB scenario lt scenarioName gt lt scenario gt Listing 18 scenario xml 76 20 21 22 23 24 Appendix A JAXB Annotations Example In order to recreate the scenario instance code from Listing 19 must be run package logic import data ScenarioSimpleData import javax xml bind import java io File public class Reader public static void main String args try File file new File scenario xml JAXBContext context JAXBContext newInstance ScenarioSimpleData class Unmarshaller unm
7. 81 82 1 Introduction If we had to define aspects of modern application mobile and service oriented aspect would be certainly among the most mentioned ones Being accessible from everywhere and anytime while providing functionality equal to user s experience from computers is a goal of application creators and most desired wish of many users Currently there are common expectations upon any of us that we are quick in our jobs and efficient at the same time It requires having all the necessary data within our reach Giving the fact that personal computers are not always available right away focus of many companies and developers have shifted on devices which are with us most of the time our mobile phones and also tablets whose market share increases literally every day Having a native application for mobile devices gives its creator advantage against common and in some cases obsolete ways to work with users data User who has just written an important note does not want to manually copy the file when he gets to the computer he wants to save it and have it available in his her computer by the moment the computer is turned on User who searches for a specific piece of information which is already available on a server does not want to turn on the computer especially if he she needs information right away such user needs to have a possibility to access the information from his her mobile phone which is most definitely o
8. A swipe driven tab changing is becoming a new navigation standard in modern applications However for providing such feature an Android s Support Library would have had to be used which would require additional comprehension of the library and its new components 17 3 File Downloading In the current state endpoints for downloading user s data files by an identifier in GET request are prepared In response to such request a binary file is returned A proposed enhancement lies in implementing a Service not a CommonService which is a decorated AsyncTask or using an Android component for background downloading file if there exists such component l getFile methods in DataFileServiceController and ScenarioServiceController 65 Chapter 17 Future enhancements 17 4 Visualizing Data File An additional step to file downloading might be allowing a user to open them In case of a plain text files should be easy to display file s content but in case of EEG data files it would be required to implement a graphic visualization of data file s content signals epochs 66 18 Conclusion The main goal of this thesis was to present a solution for gathering EEG ERP data using mobile devices After an analysis of needs and requirements the Android mobile platform was chosen for mobile application development This application can be ran on mobile phones and tablets with Android v4 0 x and newer In order to provide requested dat
9. OS Ie SO 13 6 3 1 Directory Structure l area ai 14 7 Mobile Platforms 16 7 1 Windows PHONG ast wee E A SU RD 16 wu Ic 17 T BlaekBerby a A bio A AE 18 debe a A A Sd o RP hie ad 18 7 5 Selection Decision los ran en eon e 20 8 Android Specifics 22 8 1 Resource Handling vsus SA Eee s 22 iii Contents 8 1 1 Application Localization 8 1 2 Application Layouts 5 25 Whe Lite velo an rycen el dace exeant e eR EIS SL Activity Us NS Saa se LASEK aaa aa Aaa m2 BO e AI RE wed us 5d Manifest Filet reta e dd ened A 9 Architecture 10 Server Side RESTful WS 10 1 Messages miu ies e E is 10 2 Requests and Responses 10 2 1 Servlet Definition sato orto tea ME sv dp 4 pg ore e it HIN M cou Lai Le a i MER AA AA 10 3 1 User Verification aeree 10 3 2 HTTPS and SSL oil ca 11 Client side I Creating a New Project 11 1 Creating Android Application Using Apache Maven 11 2 Projects Maven Settings ea aa EUR a 11 3 Android Manifest oaa 12 Client side II Working with Data 12 1 SharedPreferences Storing User Data 12 2 ListView and Complex Data Types 12 3 Providing Data Between Activities 13 Client Side III Rest Template 13 1 Communication Using HTTP SSL 28 29 29 29 30 3l 32 33 33 34 36 36 3T 38 40 40 40 41 43 Contents 13 2 Direct Usage of RestTemplate 14 Client side IV Navig
10. a previous run when its instance is still available The methods in this phase are e onCreate Activity is newly created here The layout is inflated and available data are filled into view elements If there is a known previous state of this activity type available information from the state can be reused e onhestart This method is called upon an Activity which was in the stopped state and now should be started again Not used as often as on Create method for overriding e onStart the activity becomes visible yet not interactive e onResume the activity becomes interactive we are in the state of productive life None of these methods can be interrupted the logic inside of them is always performed It is different from the destruction phase Before further explanation let us present a list of this phase s methods e onPause another activity becomes interactive resumed a current activity must be paused yet still visible The current activity can become resumed again or it can be stopped e onStop by now the activity is not visible any more The activity can be restarted or destroyed e onDestroy the last step before the activity is destroyed While knowing the methods let us go back to the matter of interruption While only the method onDestroy explicitly destroys an Activity instance 25 Chapter 8 Android Specifics and all of the methods should be performed it may happen that the a
11. applications is ran Currently it is with iOS one of the most used platforms but while iOS devices are quite expensive and manufactured exclusively by 18 Chapter 7 Mobile Platforms Apple Android devices have multiple different manufacturers and cover price span from very cheap ones to as expensive as best Apple device Due to the fact of many manufacturers Android stands and falls on support of various hardware and screen resolutions and depths 2 In some cases poorly HW equipped devices are equipped with new and more performance demanding Android versions which may result in overall user s frustration over slow or even unusable device It is caused by a fact that Google does not require minimum HW configuration for specific version of Android and it is only on manufacturer how well equipped device creates Moreover some manufacturers create their own user interface changes in order to distinguish their devices from other ones Since the version 4 0 codename ce Cream Sandwich Android presented a new reworked API and design guidelines which stands upon Holo theme With new devices having Android 4 0 or newer and ongoing updating of older ones there is decreasing necessity of supporting older versions of Android in order to benefit of features which new API presents Similarly to Windows Phone Android holds UI definitions separately to implementation in XML files Android applications are written in Java unless using C
12. are displayed either inside of it if the screen is large enough or right below it El Scenarios MY SCENARIOS ALL SCENARIOS Figure 14 1 Tabs as a navigation menu in the EEG Base for Android In order to provide a navigation with tabs we need to alter ActionBars behaviour and create an implementation of an ActionBar TabListener interface The custom TabListener resolves what happens when a tab is selected usually a fragment is changed unselected fragment is detached or reselected usually nothing happens The ActionBar behaviour change is quite straightforward we only need to set another navigation mode create tabs and add them to the ActionBar Override public void onCreate Bundle savedInstanceState super onCreate savedInstanceState ActionBar actionBar getActionBar actionBar setNavigationMode ActionBar NAVIGATION MODE TABS ActionBar Tab tab actionBar newTab SetText R string string identifier setTabListener tabListenerInstance actionBar addTab tab Listing 12 Single tab example of ActionBar with tabs navigation mode see cz zcu kiv eeg mobile base ui TabListener 49 Chapter 14 Client side IV Navigation 14 3 Spinner Navigation Another choice of navigation might be a spinner instead of an activity name An implementation of such navigation is a bit more difficult than the tabs mode but on the other hand it is more useful for referencing activities as well
13. as fragments Unfortunately currently there is no straightforward way to support both spinner and tabs mode in one activity at once If we want to have a spinner as a menu in an ActionBar we must set it to a list navigation mode Also we must implement a OnNavigationListener so we could handle menu item selection events The last thing we need to do is to create a SpinnerAdapter which we set together with the navigation listener to the ActionBar A working example of such implementation is used in the EEG Base for Android specifically in the NavigationActivity class A custom array adapter called MenuAdapter is created in the NavigationActivity and it needs a reference to an array of strings array of icon references and a list item layout identifier The result is visible in Figure 14 2 Dashboard Dashboard Bl Scenarios SP Experiments AL Upload file Reservations Settings reservation system tor creating Figure 14 2 Spinner navigation menu in EEG Base for Android cz zcu kiv eeg mobile base ui NavigationActivity 50 15 Client Side V EEG Base for Android Specifics Implementation details are too specific to the EEG Base for Android since this chapter to be described as a generally recommended approach to develop a RESTful web service client This chapter is dedicated to implementation specifics of the EEG Base for Android Parts of the final application in relation to their logic and packages wil
14. display detail filter fetched results or create new records Records can be fetched either by clicking the Refresh button in the action bar or by tapping the empty screen body i s e s ELS a00 scenario C nerresH Q search MY SCENARIOS ALL SCENARIOS 701 Rest test application pdf cop The Definitive Guide pdf Rest test new endpoint ZCUrootCA der la E 0 Test Rest new data model l Scenarios ate ze der MY SCENARIOS ALL SCENARIOS Test xx der remake Rest test a No records fetched yet b Fetched records with selected record for detail Figure D 3 Scenarios section Once records are fetched any of them can be selected in order to display details either in a new screen mobile phones or in a details screen section like in Figure D 3b Since records have been fetched they can be filtered by title or identifier It is done by clicking the magnifying glass icon of Search 84 Appendix D EEG Base for Android User Manual button The filter can be removed by entering blank filter string otherwise filtered results will be displayed An example of filtering results by rest keyword can be seen in Figure D 4 MY SCENARIOS ALL SCENARIOS Rest test Hadoop_The Definitive Guide pdf Rest test 2 mage jpg Rest test new endpoint ZCI tCA der Test Rest new data model certificate ZCUrootCA der 710 remake Rest test topsecret ZCUrootCA der exp create test Rest Lol Test rest File name Desc
15. for native linux development and then are compiled into class files transformed into Dalvik executables dex files Like Java packages compiled code into executable JAR files Dalvik executables are packaged into APK files which are used for distribution of Android applications Strengths e Independence of development machine OS Android SDK is available for Windows Mac OS and Linux equally e Documentation and community tutorials Whole Android ecosystem is heavily maintained both by Google and developers community which results in thorough documentation and countless How To articles e Java Android development is based on Java one of the most spread programming languages Drawbacks e Fragmentation API version fragmentation and HW fragmentation due to various devices a programmer must test functionality and behaviour over larger span of devices or use an emulator 19 Chapter 7 Mobile Platforms e Android plugin for Eclipse IDE while IntelliJ Idea in its new version offers an ideal development environment for Android Eclipse IDE with its Android plugin is still recommended for development of Android applications The problem is that an Android plugin does not work all the time as it should work e Cross device inconsistency in user experience due to different changes in the user interface per manufacturer the user can be confused when using an other Android device unlike in an other mobile platf
16. of the annotation Mapping s URL is specified by a string which appends to previous mappings Imagine that we request mapping over the whole class with value experiments and then again we request mapping mine over method which returns a marshallable container of user s experiments A GET HTTP request over experiments mine would trigger the method and a container of user s experiments would be marshalled into a response URL mapping string can also contain parameters which serve as input parameters for a linked method Every parameter must be named the same as the method s input parameter a must be wrapped inside brackets If we 31 Chapter 10 Server Side RESTful WS had method annotated as in Listing 3 and a GET request upon URL ending with experiments public 15 suffix the method getPublicExperiments would process such request and would pass integer 15 as input parameter RequestParam experiments public count public ExperimentDataList getPublicExperiments int count method implementation Listing 3 Request mapping with an input parameter in a request URL All method input parameters might not be a part of request URL string they may be a part of a request body or parameter It applies mostly to POST requests where we extract parameters using RequestParam annotation before an input variable of corresponding data type For transforming whole request body into a complex data type we must use Request Bo
17. to the original URL 5 3 Basic Comparison The fact that for implementing of a RESTful web service client we require only simple HTTP communication and using protocol s methods vastly helped to using RESTful web services as a primary solution for many simple client server applications It applies even more in case of mobile device software With no need to generate a client stub we only need to know service URLs and how to operate over them Moreover messages from SOAP web service are larger that the RESTful ones due to necessity of complying with SOAP standards On the other hand SOAP services can rely on WSDL files while RESTful web services might provide a web service description written in the WADL Web Application Description Language However WADL is not standardized and is not mandatory user must rely on developers that they provide WADL or sufficient documentation of endpoint URLs Also RESTful web services should be stateless unlike SOAP ones which implicates that SOAP web services are more suitable for other cases then RESTful web services e g state dependent sequential data processing 11 6 Java technologies 6 1 Annotations vs XML Definitions When creating a well designed modern application a certain level of code abstraction modularity and separation of semantics and implementation is mandatory What was created mainly in order to reasonably maintain large enterprise applications it became almost a part o
18. we create new records in it fill marshallable data containers with proper data return them etc Another point of view is that our service is an additional layer between controller and data layer which only returns data in a marshallable format With data access separated from controller we can easily set data transaction scopes These are set using Transactional annotations With them we wrap method execution with database session so that data which yet have not been fetched due to lazy loading would be fetched right in time Transactional session can be either with possibility to edit database content or for read only It is set using annotation s readOnly parameter It also is specific for Transactional annotation that it must annotate a method in implementation and not in an interface as it is usual For being able to use Transaction annotations a transaction manager must be already created and reference to it must be set in the servlet definition like in the following line tx annotation driven transaction manager txManager gt Listing 5 Allowing transactions annotations 10 3 Security When creating a web service two security issues occur The first issue is that a user should be able to access only data to which he she has access rights The second issue is a communication channel data are sent over not secured http channel by default and there is a risk that someone would read the communication and obtain private in
19. 15 5 User Interface The user interface classes are located in cz zcu kiv eeg mobile base ui package and its sub packages The package root contains the NavigationActivity class and the TabListener class which was mentioned in Section 14 1 The main package contains sub packages with their own classes These sub packages are named either by a data type their classes work with datafile experiment person scenario reservation or by logic or a phase their classes belong to dashboard filechooser settings startup 95 Chapter 15 Client Side V EEG Base for Android Specifics 15 5 1 Startup o n credentials Sharedpreferences gt Are credentials null Start WelcomeActivity Start NavigationActivity Figure 15 1 Activity diagram of application startup On start up in StartUpActivity application checks if there are user s credentials stored in shared preferences If so a NavigationActivity is started otherwise a WelcomeActivity is launched like in Figure 15 1 In WelcomeActivity Figure 15 2 user provides and confirms credentials which are first offline validated whether they contain a credentials data or not After the validation phase starts a TextCredentials CommonService which tries to connect to server and obtain user details If succeeds the credentials are saved and user is let to the NavigationActivity otherwise he she is informed by an error message and must either wait till the server is av
20. 2 73 74 75 Appendix B Parcelable Data Container public int getId public void setId int id this id id public String getName return name public void setName String name 1 public String getSurname return surname public void setSurname String surname 1 this surname public String getMailUsername return mailUsername public void setMailUsername String mailUsername this mailUsername mailUsername public String getMailDomain return mailDomain public void setMailDomain String mailDomain this mailDomain mailDomain 76 78 79 80 81 82 83 84 85 86 87 88 89 90 Appendix B Parcelable Data Container Override public int describeContents default value return 0 0verride public void writeToParcel Parcel dest int flags dest writeInt id dest writeString name dest writeString surname dest dest writeString mailUsername writeString mailDomain Listing 20 Example for Parcelable data container which handles XML marshalling 80 C Installing Android Application C 1 Maven Build and Install In order to build and install an application from a source Maven 3 is required Open console and enter directory with pom xml file Inside of it build project mvn clean package If the build finishes successfully an installation package eeg base apk should be present in the target directory Now
21. B 11 2 Project s Maven Settings Let us set the project using Maven so it would resolve dependencies build and deploy an android application into device Such settings are defined in pom xml file A groupld will be identical to aforementioned application package artifactId will be application name in lower case with dots as word separators e g eeg base Since we are creating an Android application the packaging will be an Android application package apk Now we must define framework dependencies On the Maven repository website we search for required libraries and copy a dependency snippet between dependencies pair tags Like this we find and define Spring for Android Rest Template and Simple XML framework Moreover we must define Android SDK dependency so Maven would connect the SDK with a compiler It is done in a similar way as other dependencies but this one has parameter scope which is set to provided and it looks for a system environment variable of ANDROID HOME The ANDROID HOME variable should be set as a path to the location of Android SDK installation The last step will be setting up Maven build plugins which will compile and package our application For compiling the Java code we use Maven Compiler Plugin and in order to compile the Android code and package it into an APK we must define plugin dependency to Android Maven Plugin This plugin also allows project to link other APK files as library dependencies which wou
22. ICATION XML string belongs here Second we create the whole HTTP message entity The HttpEntity object constructor the object is here typed as a Person instance consists of a Person instance itself and previously created HTTP header instance 44 Chapter 13 Client Side III Rest Template With existing HTTP entity we only need to create a new RestTemplate instance and use it for performing a request A constructor parameter for the RestTemplate would be our custom client HTTP request factory from Section 13 1 And in order to RestTemplate marshall a Person instance into a XML message we must add a XML message converter let us use a SimpleXmlHttpMessageConverter class for this purpose The last step is client server interaction itself The Rest Template offers many HTTP methods in this case we need a POST method which is commonly used for a new record creation Moreover we expected except OK message information about newly created user in response therefore we use a postForObject method which has parameters of URL where to perform a request HTTP entity with previously set header fields and a expected response object class in our case Person class The whole example looks in code like in the following snippet assume initialized instance of Person class named person HttpAuthentication authHeader new HttpBasicAuthentication username password HttpHeaders requestHeaders new HttpHeaders requestHeaders s
23. Reason to granted mark found Error found Male is 1 Uu could not find menu without manual Dark layout More 2 9 8 10 tabs cannot be changed by swipe gesture Female 23 0 9 10 Would prefer larger font size ORT 17 0 8 10 Could not find menu without manual preference of Windows Phone UI Table 16 2 User testers and their marks to the application Only one error was found during user testing This error was fixed and did not affect other testers The first tester was also an EEG researcher No further errors were found and all test scenarios were performed successfully A 1 19kB large file was uploaded during user testing but a file of 250MB size was uploaded in a separate test 64 17 Future enhancements Capabilities of discussed RESTful web service server side and its client side can be further improved Following improvements are outside the scope of needs discussed in this thesis but user experience would be improved if the improvements are implemented 17 1 WADL Support Currently there are no other files the server side controller classes where information about existing endpoints of RESTful web service would be collected in Implementing automatic WADL file generation on server start up may be a viable solution for developers who would like to implement an own client application for EEG Base This WADL file would be available at main endpoint URL rest afterwards 17 2 Changing Tabs by Swipe Gesture
24. University of West Bohemia Faculty of Applied Sciences Department of Computer Science and Engineering MASTER THESIS Pilsen 2013 Petr Miko University of West Bohemia Faculty of Applied Sciences Department of Computer Science and Engineering Master Thesis Mobile system for management of EEG ERP experiments Pilsen 2013 Petr Miko I hereby declare that this diploma thesis is completely my own work and that I used only the sources cited Pilsen May 16 2013 Petr Miko cima tices beo de Abstract Gathering EEG Data Using RESTful Web Service and Android The goal of the thesis is to present a problem and a solution of mobile gathering of EEG data EEG researchers need to have their data available and synchronize them in manner of reading and writing meta data and uploading data files This thesis presents development of a RESTful web service on Java EE server and creation of an Android RESTful web service client while respecting requirements and needs of EEG researchers Keywords mobile web service Java RESTful Android EEG Spring Rest Template Contents 1 Introduction 1 2 EEG and ERP 3 3 EEG Base 4 4 Requirement Analysis 5 5 Web services SOAP and REST 8 5 1 SOAP Web Services ue e a is 8 52 RESTful Web Services a AA eR ES 9 5 3 Basic Gomparison cos pr e ea 11 6 Java technologies 12 6 1 Annotations vs XML Definitions 12 p eA wo fs IN dus di 13 6 3 Apache Maven Scd eno Soo Ao Sedo
25. a synchronization it was analysed what type of data is needed to transfer As a result was developed a RESTful web service server side and its client counterpart will be developed Both allow to save and read meta data since they are needed the most and to save larger data files which are needed only to be stored The implementation process of such RESTful web service provided interesting insight into modern Java frameworks and technologies Even more it was interesting that since Android platform is based on Java many libraries and frameworks may be used in Android too like the Rest Template library On the other hand the Android platform has its specifics in design and expression possibilities A lot of energy has to be put into finding solutions to issues like designing navigation internal data transfer screen orientation change issues etc Also security has a significant role in presented solution Therefore a custom implementation of HTTP client factory for Rest Template was created This factory implementation supports all SSL certificates EEG Base does not have own certificate yet and resolves issue with file buffering into memory which is present in default implementation As a result of effort put into thesis s solution a fully functional RESTful web service was implemented into the EEG Base An Android client application EEG Base for Android was created as well The application uses the web service for client server communicati
26. ablets where a calendar is displayed because Sunday as a first day is confusing for some users 60 Chapter 15 Client Side V EEG Base for Android Specifics 15 6 Utilities Utility classes are located in the package cz zcu kiv eeg mobile base utils These classes gather useful methods used across the application e ConnectionUtils provides the method sOnline which checks if there is an existing network connection e FileUtils contains methods for obtaining files MIME type and its file size in a human readable format e LimitedText Watcher is an interface implementation used over Edit Text components which have a maximal text length set It provides means to update another TextView component with a message of characters left till maximum text length limit is reached e ValidationUtils class gathers methods used for various commonly used validation operations like checking validity of email string URL string or just checking emptiness of a string 61 16 Testing Server side functionality was split into two sections a service core functionality and a URL mapping functionality The service core functionality was verified using the unit testing framework JUnit 4 while the URL mapping was tested by the EEG Base for Android client application Unit tests are located in cz zcu kiv eegdatabase webservices rest test package The transactions and dependency injection work similar as in the tested components only a s
27. acceptable user experience over such large amount of devices As well as with localization strings there may be multiple layout directories with proper qualifiers which allow us to provide desired user experience across various devices 8 2 The Life Cycle The foundation stone of Android applications are Activities Services and AsyncTasks Activities are primarily meant to display GUI and to interact with a user Services and AsyncTasks provide parallel operations to a GUI thread i e Activities Important is that all the components have their life cycles The life cycle clearly defines where a specific logic should be putted Because of in this thesis we will not meet Services any further let us focus on a life cycle of an Activity 24 Chapter 8 Android Specifics 8 2 1 Activity An Activity life cycle can be simply described as a phase of creation productive life and its destruction The creation and destruction phases consist of several methods where each method has special purpose All of the life cycle methods have their default behaviour which can be altered In order to alter the activity s behaviour we need to override the default implementation yet in most cases it is mandatory to call super equivalent of a given method in order to all internally required operation would be performed The creation process is the life cycle part where layout is inflated on a screen and filled with data or simply reused from
28. age ain Ba tage ee ER Id uS 76 scenario Xil Js uu AA A A e 76 Tteadoi java oce oso A RES A SV 77 Example for Parcelable data container which handles XML POST 2 wu are ON eee dn de 80 70 List of Abbreviations API Application Programming Interface APK Android Application Package CRUD Create Read Update Delete DAO Data Access Object DOM Document Object Model EEG Electroencephalogram ERP Event Related Potentials GUI Graphical User Interface HTTP Hypertext Transfer Protocol IDE Integrated Development Environment INCF International Neuroinformatics Coordinating Facility IoC Inversion of Control ISO International Organization for Standardization JAXB Java Architecture for XML Binding JDK Java Development Kit JSON JavaScript Object Notation MVC Model View Control design pattern ORM Object relational Mapping POM Project Object Model REST Representational State Transfer RPC Remote Procedure Call SAX Simple API for XML SDK Software Development Kit SOA Service Oriented Architecture SOAP Simple Object Access Protocol SSL Secure Sockets Layer TLS Transfer Layer Security UDDI Universal Description Discovery and Integration UI User Interface URI Uniform Resource Identifier URL Uniform Resource Locator UX User Experience WADL Web Application Description Language WSDL Web Ser
29. ailable if there was a connection issue or must correct the credentials Inflating layout Ul elements ready for credentials input E Validations Errors amp OK A Gestcredental Commonservice gt Error With verification or o e OK Start NavigationActivity Figure 15 2 Activity diagram of WelcomeActivity 56 Chapter 15 Client Side V EEG Base for Android Specifics 15 5 2 NavigationActivity When the user is in NavigationActivity all sections of an application are accessible Simple sections are resolved as fragments which are replaced inside the activity Other sections which demand further navigation elements tabs are resolved as activities which are started from the NavigationActivity see Figure 15 3 The onStop and onRestart actions relate to Activity s life cycle when another Activity takes place on the top of the GUI stack The onDestroy can be possibly called only by the garbage collector when the application is inactive ie turned off Such behaviour is correct since the StartUpActivity creates a new instance during a new application run Inflating layout onRestart UI ready Selected navigation item onDestroy stopped Fragment Replacing fragments Activity onSto P Starting selected Activity Figure 15 3 Activity diagram of NavigationActivity Browsing through application sections is resolved using a spinner like list menu as discussed
30. arshaller context createUnmarshaller ScenarioSimpleData scenario ScenarioSimpleData unmarshaller unmarshal file System out println Scenario ID scenario scenariold System out println Scenario name scenario scenarioName catch JAXBException e 1 e printStackTrace J Listing 19 Reader java Standard text output from such code is the following Scenario ID 12 Scenario name Test JAXB scenario TT 23 24 25 26 27 28 32 33 34 B Parcelable Data Container import android os Parcel import android os Parcelable import org simpleframework xml Element import org simpleframework xml Root Root name owner public class Owner implements Parcelable public static final Parcelable Creator lt Owner gt CREATOR new Parcelable Creator lt Owner gt public Owner createFromParcel Parcel in return new Owner in J public Owner newArray int size return new Owner size I F Element private int id Element private String name surname Element required false private String mailUsername mailDomain public Owner public Owner Parcel in id in readInt name in readString surname in readString mailUsername in readString mailDomain in readString 78 35 36 37 38 39 40 42 43 44 45 46 47 48 49 54 55 56 57 58 62 63 64 65 66 67 68 69 70 7
31. ation AE rn Menys ad acer o ts Ga aes de 14 2 DIT Ace aa Aa da a a Met ac a a AS Tabs Naxigatiolss s 1 bs para atar E to deg 14 3 Spinner Navigation ic A a 15 Client Side V EEG Base for Android Specifics 15 1 Resources 15 2 15 3 15 4 15 5 16 Testing 15 1 1 Application Localization aci siste ira 15 1 2 Application Layouts sr is a Archetypes Project Specifics a o a a IDA Contaihet 2 a dais fe aen AR a be ba a 15 32 Adapter vu au qe A Web Service Communication LL User Interface gt gian A xA DA eet ue 155A Startup ao pa A Eur bsc EH ei 15 5 2 NavigationActivity un kd eer ko Ro OE BS a 15 5 3 Record Browsing e ERE TANE anse at 15 5 4 Creating a New Record 15 5 5 Choosing File for Upload conn dota dat o a A Da afi eut Bae A a NU Bias Ai ve ERE 15 6 Utilities 17 Future enhancements prob WADL SUpport os mios Gier a Ea Sero rt oe 17 2 Changing Tabs by Swipe Gesture 46 46 47 48 49 50 51 ol ol ol 92 93 93 54 54 59 56 57 57 59 59 60 61 62 Contents T S File Downloading tke dc re ER ESO o th e 17 4 Visualizing Data File 2 2 24 42221 18 Conclusion A JAXB Annotations Example B Parcelable Data Container C Installing Android Application C 1 Maven Build and Install 2 Install from APK s aa coo Roo vede x Su Ese D EEG Base for Android User Manual vi 67 75 78 81 81
32. chapter Chapter 4 Requirement Analysis EEG Base client application Creates a new artifact record lt lt include gt gt EEG Researcher es SS Books EEG laboratory for a research group Creates a new digitization record Figure 4 1 EEG Database client application use case diagram 5 Web services SOAP and REST When a client application needs to use a service located on a server using the remote procedure calls or remote method invocation can be difficult Large pieces of shared code can be required and the solution will be probably platform dependent But there is a better solution to use a web service Every web service specifies its own communication protocol and provides a public interface for access thus it is accessible equally from multiple platforms and keeps services modularity without a need of shared code There are two separate web service technologies with different approach to the execution of remote procedure calls e SOAP web services e RESTful web services 5 1 SOAP Web Services Older yet still vastly used web services are SOAP web services The SOAP represents name of a communication protocol which these web services use a Simple Object Access Protocol This protocol is responsible for delivering messages usually via the HTTP protocol which is used due to lower probability of being blocked by firewalls during their route Every SOAP web servic
33. ctivity must be killed e g due to a sudden need of freeing memory In such case only onPause method run is guaranteed If there are any critical data to be stored it should be done here However the activity is still visible in onPause method therefore in order to prevent slowness of user interface no large data should be processed here Fragments Fragments are components subsidiary to activities they represent reusable components which are used within activities As Activities they have own life cycle which is dependent on the parent activity The life cycle has its methods which can be overridden as well as in activities Although Fragments are also used in this thesis application it is not necessary to describe each method their functionality is similar to activities functionality and further details are available on Android Developers website 7 8 2 2 AsyncTask AsyncTasks are Android components for performing operations in parallel to a GUI thread They require a reference to a visible activity both for context reference and their ability to write into the GUI thread before and after their background processing The available methods of AsyncTask are e onPreExecute operations which should be performed on GUI before background processing starts e onProgressUpdate operations performed when progress is updated from doInBackground method e doInBackground all the heavy lifting which should be perf
34. d data storing itself must comply with a set of requirements in order to cover the needs mentioned The requirements are based upon the experimenters needs and were discussed with EEG researchers of the University of West Bohemia e Provide access to experimenters data from almost everywhere e Access itself must be simple user friendly and intuitive e Creation of new data file records is usually not needed nor possible without a computer which would process them unlike creation of meta data records Meta data contain important information by themselves so it is desired that they would be available any time for further operations This fact results in a requirement that data files must be only stored to EEG Base while meta data must be available any time either for storing or for retrieving them once again e Experiments and scenarios must be creatable through the client application Moreover these requirements originate with experimenters use cases which were also identified and are visible in Figure 4 1 With services already existing inside the EEG Base application a proper communication interface for the client server contract must be defined The best solution are web services which provide clean and simple abstraction with clear definition of communication usable across platforms In this case RESTful web services are a perfect fit due to small communication overhead and simple implementation details in the following
35. d screen e ov stes dig apo deg tertie ate een Scenarios section eh A A ded A ROS Filtering fetched records siria add os Creating new scenario 2n Creating new experiment o 15 21 23 24 28 36 49 50 List of Figures D 7 Experiment data file upload D 8 Reservations D 9 Settings 69 List of listings N BE CON D OK W 11 12 13 14 15 16 17 18 19 20 Servlet definition in web xml lll 30 Enabling MVC annotations in cz zcu kiv eegdatabase webservices rest noc AO A c Rie ye See e TET LEE 31 Request mapping with an input parameter in a request URL 32 Exception handling in web service controller 32 Allowing transactions annotations 33 Allowing Spring Security annotations 34 Forcing secure channel for RESTful web services in web xml 34 Rest Template example oy sud weder dI sd ee S 45 Example of inflating menu resource in ExperimentActivity 47 Example of handling menu items events 4T Turning icon into Home Up button 48 Single tab example of ActionBar with tabs navigation mode 49 Example of uploading a Scenario file with its meta data 55 Class annotations for loading Spring context 62 Manual logging in within Junit 4 test 63 scenariosimpleData java x oec dc eec at e Ear e e Rn d 75 VVI ter Bd m deor teo ture ar Bog t
36. dling of transactions when operating with the data layer 10 2 1 Servlet Definition A servlet name and its mapping must be defined in web xml at the beginning Let us create a servlet named rest 1 lt servlet gt 2 lt servlet name gt rest lt servlet name gt 3 lt servlet class gt 4 org springframework web servlet DispatcherServlet 5 lt servlet class gt 6 lt servlet gt 7 lt servlet mapping gt 8 lt servlet name gt rest lt servlet name gt 9 lt url pattern gt rest lt url pattern gt 10 lt servlet mapping gt Listing 1 Servlet definition in web xml Having this servlet definition we create a new servlet file in the WEB INF directory called rest servlet xml Inside of it we create the following beans e org springframework web serulet view ContentNegotiating ViewResolver e org springframework web serulet view xml Marshalling View e org springframework orm jaxb Jaxb2Marshaller e org springframework web multipart commons CommonsMultipartResolver Content Negotiating ViewResolver resolves view requests by its content type In bean s body we can define multiple view implementations into default Views property list In our case we define xml view implementation which we also set as default by setting application xml as default content type It means that unless the content type is different from aplication xml a XML response is returned 30 Chapter 10 Server Side RESTful WS View implementatio
37. dy annotation During web service processing an error may occur an exception is thrown Every exception should be intercepted and handled in a way that user is notified in a proper way ExceptionHandler annotation serves for exception interception and its value is set to an exception type class This annotation is being placed over the method which should handle the exception in some way In our web service we send error message through a servlet response The error message has its HTTP Status set to a proper value and an exception string as a message body ExceptionHandler RestServiceException class public void handleRSException RestServiceException ex HttpServletResponse response throws IOException response sendError HttpServletResponse SC_INTERNAL_SERVER_ERROR ex getMessage Listing 4 Exception handling in web service controller 10 2 3 Service Service is another Spring component which is created inside the container It provides a specific set of functionality which is provided to other components which use it 32 Chapter 10 Server Side RESTful WS In our case we define service s methods in an interface using which we recover implementation bean for autowiring and an interface implementation which will be annotated using Service so that Spring would create its bean The services contain logic of web service which is not related to HTTP request handling but to the behaviour itself It means that
38. e provides public interface which is accessible through specified URL This service point of entry is called an endpoint When a user wants to use capabilities of a SOAP web service he she needs to know the exact endpoint and an interface definition which is contained in a WSDL file WSDL is a XML file written using the Web Service Definition Language which states what service methods are available which objects are used as return types and method parameters and what is the structure of such objects In terms of RPC WSDL defines a server stub Client stub is represented by source files which are generated using the WSDL file These files are used 8 Chapter 5 Web services SOAP and REST within a client application afterwards ServiceRegistry publish E bind x Service Requestor Service Provider Figure 5 1 Communication diagram between web service elements 3 If we want to relate to a common model of web services as in Figure 5 1 relations would be following e Service Registry A location which contains information about available web services and their providers These pieces of information are saved by service providers themselves each web service is registered in a registry implemented using Universal Description Discovery and Integration protocol UDDI 17 and a WSDL file which represents the service s interface is generated or manually created for each service e Service Pro
39. eams usually binaries e values files containing values used in an application There is an existing naming convention for following files arrays xml value arrays colors xml colours values dimens xml dimension values styles xml styles definitions e xml files which are accessed using Resources getX ML method Resources can be further distinguished using suffixes in resource directory name The suffixes which are separated by dash from one another represent device s parameters or abilities qualifiers Using them we can create multiple resource directories in which we put resource files which belong only to devices with a specific set of attributes However if no qualifier is used or 22 Chapter 8 Android Specifics no resource is found in a directory with specific qualifier a default directory with no qualifier defined is used as a fallback A complete process of selecting proper resource is observable in Figure 8 1 and the list of available qualifiers is available on Android Developers site 12 Eliminate qualifiers that contradict the device configuration Identify the next qualifier in the qualifier list Do any resource Continue until only one directory directories for the desired use this resource qualifier is left Eliminate directories that do not include this qualifier in case of screen density pick the best ma
40. ed 20 April 2013 9 Google Menus http developer android com guide topics ui menus html unknown Online accessed 25 April 2013 10 Google Property animation http developer android com guide topics graphics prop animation html unknown Online accessed 25 April 2013 73 Bibliography 11 12 13 14 17 18 19 20 21 Google Providing resources Grouping resource types http developer android com guide topics resources providing resources html ResourceTypes unknown Online accessed 16 April 2013 Google Providing resources How android finds the best matching resource http developer android com guide topics resources providing resources html BestMatch unknown Online accessed 7 April 2013 Google View animation http developer android com guide topics graphics view animation html unknown Online accessed 25 April 2013 Apple Inc Cocoa touch https developer apple com technologies ios cocoa touch html unknown Online accessed 28 April 2013 Microsoft Xaml overview http msdn microsoft com en US library ms752059 aspx unknown Online accessed 28 April 2013 Roman Nurik Done discard design pattern http www androiduipatterns com 2012 08 roman nurik on done discard html August 2012 Online accessed 26 A pril 2013 OASIS Uddi xml org http uddi xml org uddi 101 2006 Online accessed 5 April 2013 Orac
41. epository A basic set of plugins required for Maven to run and a repository reference for downloading other dependencies and plugins are located in Maven s Super POM Every user creating POM file inherits this POM either directly or indirectly through a parent POM Moreover Maven defines a clear on disc directory structure A developer can rely on Maven that he she finds expected files inside of an expected directory location Apache Maven provides more features than mentioned directory structure and extensibility another one worth to mention might be creating tags and branches in repository uploading build application to a production server etc This technology has some drawbacks The most annoying one is possible dependency collision when Maven cannot decide which library from which dependency should be used In such situation Maven build results in an error and user must resolve it This is a known issue which is continuously attempted to resolve Maven 3 has better dependency resolving than Maven 2 or lately using an Aether library for dependency management which should bring better behaviour than native implementation But even with its occasional dependency issues Maven usage spreads in Java projects world wide as it gradually becomes a standard in definition of keeping and maintaining larger Java projects 6 3 1 Directory Structure Every Maven based project has a directory structure as it is visible in Figure 6 1 unl
42. erence is removed and the dialog is closed The CommonsService has in also a methods for simple message passing to a CommonActivity and a method for passing an Throwable instance Such throwable is analysed and if it is of known type related to common issues only a text message is passed forward This is used for handling errors during client server communication where exceptions provide only codes or hardly readable messages There is only one limitation to CommonServices they must be executed http j mp androidassetstudio 52 Chapter 15 Client Side V EEG Base for Android Specifics serially in order to prevent issues with progress dialog It is achieved by executing on an Executor pool with a AsyncTask SERIAL EXECUTOR parameter Both CommonActivities and ComonServices decorate their parent classes by simple access to shared preferences which contain user s credentials The last archetype is a SaveDiscard Activity This activity inherits from a CommonActivity and is meant for views where accepting and storing of displayed data or dismissing them are the only options available This activity and its style are based on Done Discard Android UI design pattern 16 The package of archetypes is cz zcu kiv eeg mobile base archetypes 15 3 Data Layer All classes which are meant for containing and providing data are placed in the cz zcu kiv eeg mobile base data package Only two classes are in the package root Se
43. ess it is defined otherwise Either IDE creates the directory structure when we choose that we are going to create a new Maven based project or we must create the directories manually Source files are located in the src directory resource files in the res directory and files used or generated during build are located in the target directory The pom xml file contains all the information required for performing build 14 Chapter 6 Java technologies and also contains meta data about project src res target pom xml Figure 6 1 Maven Directory Structure 15 7 Mobile Platforms Before creating a mobile device application a platform must be chosen While in computer software we can usually choose programming language the mobile platforms are usually limited by a specific programming language or a framework in which developers create their applications In this chapter all major platforms for mobile devices will be described with their specifics and drawbacks 7 1 Windows Phone Windows Phone is a Microsoft s proprietary mobile platform which is based on Windows CE Windows Phone 7 x first release in 2010 and on modified Windows N T Windows 8 x first release in 2012 kernels This platform provides truly distinguished user experience against other platforms due to its user interface based on Modern Design Language previously called Metro which is based on a tiles driven interface Each tile contains a specific s
44. et of information which is related to the application to which the tile belongs In terms of programming languages and frameworks Windows Phone is built upon with Microsoft s NET framework User interface graphics is defined in special XML files called XAML files 15 XAML is a language based upon XML and defines Ul elements locations and their behaviour using events and data bindings This design language is a part of Windows Presentation Foundation module of NET framework While the Ul and UX basics lies in Modern Design Language and Windows Presentation Foundation as a rendering framework in terms of programming Windows Phone platform uses NET framework and C as a programming language C allows to developers fully object oriented programming while Ul design definitions are located in separate XAML files Strengths e Free optimized IDE for WP application development Visual Studio Express 2012 for Windows Phone e C as a simple and powerful OOP language 16 Chapter 7 Mobile Platforms e WP devices must comply with Microsoft HW specifics ergo there are no weak devices and almost unified HW environment Drawbacks e market share currently below 2 of global market e proprietary requirement of MS Windows for development for Windows Phone 8 x development are required Windows 8 7 2 iOS All devices created by Apple Inc are powered by iOS operating system As well as Windows Phone the iOS is not an open s
45. etAuthorization authHeader requestHeaders setAccept Collections singletonList MediaType APPLICATION XML requestHeaders setContentType MediaType APPLICATION XML SSLSimpleClientHttpRequestFactory factory new SSLSimpleClientHttpRequestFactory RestTemplate restTemplate new RestTemplate factory restTemplate getMessageConverters add new SimpleXmlHttpMessageConverter HttpEntity lt Person gt entity new HttpEntity lt Person gt person requestHeaders Person response restTemplate postFor bject url entity Person class Listing 8 Rest Template example 45 14 Client side IV Navigation Using a proper navigation is a crucial part of every application In previous versions of Android were key navigation elements located in options menu or they were present as view elements like buttons and hardware keys Our application as well as EEG Base for Android is built upon Android SDK newer than Ice Cream Sandwich so our focus must be targeted on the ActionBar which now handles most of navigation within the application 14 1 Option Menus There are two possible ways to invoke options menu by a hardware button or by clicking on menu icon on the ActionBar While the menu icon may not be visible on devices with hardware menu button on devices without it is visible every time a menu item is set into options menu The options menu can be defined in two ways directly in a code or by creating a menu reso
46. f clean code best practices This level of abstraction modularity and semantics separation was at first achieved using XML files XML files are suitable thanks to their flexibility of writing a required schema which we need to contain specific information without loss of descriptiveness This approach is still widely used but it has a drawback in necessity of keeping both implemented code and its XML description Annotations represent other approach which allows us to define code specifics right in the code implementation Thus there is no further need for searching proper component configuration because all of its semantics is defined right next to the code itself Annotations are in its raw form a special form of interfaces which are load and separated using Java reflection technology Also annotation definitions are usually simple and do require much less text written for proper settings of component s behaviour than the XML alternative 21 Using annotations becomes vastly used approach in modern applications and is recommended while there are still cases when XML definitions are either easier or provide other benefits over the annotations due to the fact that annotations are still a rising technology As examples of frameworks where XML definitions coexists with annotations we can point out Spring framework Hibernate or JAXB Bearing in mind the benefits of annotations simplicity while keeping the same information and behaviou
47. format and be sent to the client In our application are used XML messages The JAXB framework is used for Java object XML message transformation While we could reuse existing data containers of current implementation we assume that the internal data containers might change in time in matter of adding or removing its properties In order to prevent the necessity of editing a client code every time this internal change occurs we create border data containers which contain only required properties and which are used specifically for our RESTful web service Our JAXB annotated data containers are automatically marshalled and unmarshalled in Spring MVC s controllers every time a data container is received in request or sent via response In the EEG base such data containers take place in the wrappers subpackage of its parent RESTful endpoint and their name ends with a Data suffix 10 2 Requests and Responses As in a Java Enterprise web application we need to define a servlet which handles incoming requests and outgoing responses 29 Chapter 10 Server Side RESTful WS For creating a web service endpoint itself is recommended to create a controller class service interface and service implementation Using controller we handle HTTP requests using service which is autowired into the controller using dependency injection by its interface Separation of service implementation and its controller is recommended due to better scope han
48. formation 10 3 1 User Verification A perfect solution for the first issue is the Spring Security framework It allows to create a semi session for each incoming request and destroys it when the request is handled It would be probably the most needed feature 33 1 2 8 9 Chapter 10 Server Side RESTful WS for RESTful web services where is no need to create and keep a classic session due to web service stateless architecture For user authentication itself it is only needed that incoming request had an Authentication HTTP request header set Another benefit of Spring security is its support of annotations Applying restrictions in accordance to user s rights over a method or class was never easier all that is necessary is to put Secured annotation over the class or method and put the following line into servlet definition otherwise annotations won t be used lt security global method security secured annotations enabled gt Listing 6 Allowing Spring Security annotations The Spring Security framework itself must be configured for the application to run properly but its configuration is not a matter of this thesis 10 3 2 HTTPS and SSL A Java EE application can automatically switch communication to a secured channel if server allows it For the Tomcat server it means to create a certificate or use an existing one and assign it to a secured socket which is used for HTTPS communication afterwards the
49. hen creating a new experiment we must fill all the information required as in the case of a new scenario record Some of the supplementary information may be created during experiment creation like new subject person electrode location etc It is done using buttons with the plus icon which opens a new screen activity and returns back when the record is created A multi selection list is specific for this application It requires unlike a classic list menu a confirmation of selection This applies to items with possibility of multiple records like electrode locations Figure D 6b 86 Appendix D EEG Base for Android User Manual X scum E swe Research group ddd drxgct Reterx Scenario None None pokusnej kr lik Kr l ek Subject Artifact Digitizations Weather a New experiment screen b Multi selection list Figure D 6 Creating new experiment In the case of experiments files are not uploaded during experiment creation process File upload from section Upload file must be used since there may be a continuous need of file uploading A proper experiment Experiment spinner and a file Select file button using file browser like in Figure D 5a must be selected in this section and then confirmed by Upload file button Figure D 7 87 Appendix D EEG Base for Android User Manual AL Upload file Experiment ahoj 01 01 1999 22 00 01 11 2010 22 00 File description Description
50. hes e Code On Demand a server might provide to client a code which executes on the client side and provides extra functionality This principle is purely optional in the REST architectural style While SOAP protocol extends HTTP REST reuses HTTP methods of GET PUT POST and DELETE to perform CRUD operations over specified URL For an information transfer it is used HTML XML or lately popular JSON To information transferred we refer as of resources and mentioned HTTP methods are used for analogical operations over them By mentioning a RESTful web service we mean an API which complies with the REST specification and also communicates using XML or JSON via the HTTP protocol using its methods A RESTful web service s server side listens on specific URL which usually contains a name of a domain object with which HTTP methods should work Let us say there is URL ending with suffix experiments A common expectation for such URL is that using HTTP methods we can e fetch all experiment records using a GET method I Create Read Update Delete recognized as basic data operations Application Programming Interface 10 Chapter 5 Web services SOAP and REST e remove all records by a DELETE request e replace all records with a PUT method e create a new experiment record using a POST HTTP method For updating or deleting a single record we would need to know a resource identifier which is usually put as a suffix
51. id Application Using Apache Maven Using Maven for defining a project provides us many features like src mentioned in Section 6 3 while res the most beneficial ones for us are target clear directory structure automated pom xml library dependency resolving and AndroidManifest xml automated deployment of application project properties itself With Maven we need an on disc file structure like displayed in Figure 11 1 Such structure can be achieved either manually or using IDE which Figure 11 1 Android project on disc file structure is recommended The next important step is to clarify the following aspects of the current application e Minimal SDK version a minimal required version of Android SDK to run is 15 which represents Android 4 0 x e Application package in which are located source classes This should not be changed even more when the application is available on Google 36 Chapter 11 Client side I Creating a New Project Play where the package name serves as an application identifier e Required libraries in our application we will use the Rest Template library from the Spring for Android framework in order to simplify RESTful web service creation Also a library for XML marshalling will be necessary because Android does not provide JAXB as in Java the Simple XML framework is used since it provides almost identical behaviour while using annotations like in JAXB see Appendix
52. ient we create an instance of MultiValueMap into which we set all meta data under proper keys and a single FileSystemResource reference to file in device s memory with a file map key With these settings Rest Template sends file as a MultiPart object which is by the key names binded to proper Controller method s parameters An example of sending scenario file is visible in Listing 13 FileSystemResource toBeUploadedFile 2 new FileSystemResource scenario getFilePath 3 54 Chapter 15 Client Side V EEG Base for Android Specifics MultiValueMap lt String Object gt form new LinkedMultiValueMap lt String Object gt form add scenarioName scenario getScenarioName form add researchGroupId Integer toString scenario getResearchGroupId form add description scenario getDescription form add mimeType scenario getMimeType form add private Boolean toString scenario isPrivate form add file toBeUploadedFile HttpEntity lt Object gt entity new HttpEntity lt Object gt form requestHeaders ResponseEntity lt Scenario gt response restTemplate postForEntity url entity Scenario class Listing 13 Example of uploading a Scenario file with its meta data Since uploaded files may be large do not forget to disable file buffering prior its sending otherwise the application will run out of memory It is managed by setting a false into a request factory method setBufferRequestBody
53. in Section 14 3 This activity on start up fills its body with an instance of DashboardFragment which contains only a welcome message 15 5 3 Record Browsing There are three stand alone sections for browsing data in the EEG Base for Android e Experiments located in Experiment Activity e Scenarios located in ScenarioA ctivity 97 Chapter 15 Client Side V EEG Base for Android Specifics e EEG Lab reservation times located in ReservationFragment While ExperimentActivity and ScenarioActivity are separate activities created from the NavigationActivity the ReservationFragment is a fragment which replaces NavigationActivity s content so its activity diagram is slightly different from Figure 15 4 since there is no Up button Inflating layout V ListView changes get visible X UI ready P User selects view element Up button ietVi i 4S Listviw item A Display record details Add items into list of records Control element Start proper create Create record P Tab Replace fragment activity for result p 9 Refresh Fetch records using proper CommonService Figure 15 4 Activity diagram of activities with tabs for record browsing In all three sections you can fetch existing records from the server create new ones in a separate dedicated activity AddRecordActivity for reservations ExperimentAddActivity for experiments and ScenarioAddActivity for scenarios
54. ive experimenters might find themselves in situation when they must work with incomplete information or postpone their current activity till they can access the information required A solution must be presented for these unresolved needs of data gathering and data storing Giving the fact that the EEG Base offers both the functionality and information required an obvious solution is to use services of the EEG Base with a mobile device application Mobile devices are the perfect solution for filling the unreachable computer gap because they are in present day almost always with us and do provide Chapter 4 Requirement Analysis internet connectivity In addition modern mobile operation systems and platforms built on them provide a solid and stable runtime for creating powerful client applications that can cover experimenters needs Despite the facts that there are laptops with mobile internet connection and that the mobile phones might provide internet connection using tethering technology the mobile phone by itself is more accessible in terms of device size and faster in terms of time required to start to use the application Time to launch a native application in an already running mobile phone is shorter than time required to start a larger laptop in which a web browser would have to be started Mobile devices with right application provide better user experience than their possible alternatives Solution for data gathering an
55. l be presented in following sections 15 1 Resources The EEG Base for Android uses default a resource structure as it is discussed in Section 8 1 15 1 1 Application Localization The application supports English and Czech languages There are two values directories one without a language qualifier and the second one with a cs qualifier strings zml files which contain string values are in both of them as well as arrays rml which contains string arrays in proper language 15 1 2 Application Layouts Tablets and mobile phones have different layouts of different sizes in order to keep information readable and the user experience intact As a threshold for distinguishing where to use mobile or tablet layout a minimal width qualifier of 600dp was used It is usually a width of 7 tablets like Nexus 7 Portrait and landscape alternatives are provided as well In the case of large layouts like layout for adding a new experiment layouts were separated into partial files which are included into main layout using the include tag in layout s XML file Including sub layouts benefits us of possibility to present 51 Chapter 15 Client Side V EEG Base for Android Specifics different user experience across various devices by creating different sub layout per different device like in mentioned phones or tablets Icons of different size for various screen densities are also provided since it is a standard in an Android application deve
56. ld be impossible without it The only drawback of the Android Maven Plugin is that it requires Maven at least in version 3 With all these items set we can build our application and deploy it directly to our connected device with the following command Ihttp mvnrepository com 3T Chapter 11 Client side I Creating a New Project mvn clean package android deploy android run The clear command clears the workspace from previously compiled files the package will create the APK file the android deploy installs the application into a connected device and finally the android run starts the application in the device A prerequisite to successful application deploy into an Android device is to have enabled the USB debugging in the Developer Options section of system settings on device Also note that Android currently supports only Java 1 6 which should be set in Maven Compiler Plugin and that our application will require SDK at version higher than 15 inclusive belongs to Android dependency settings As an example may serve POM file of EEG Base for Android which is on attached DVD 11 3 Android Manifest In the Android Manifest we need to set the package name and application version as first ones of many parameters The package name is identical to package where the source classes are located in application version is set as pleased The next important thing is to set SDK reference The reference is set through a minimu
57. le Establishing a secure connection using ssl http docs oracle com javaee 5 tutorial doc bnbxw html 2010 Online accessed 29 April 2013 Edward Ort Java architecture for xml binding jaxb http www oracle com technetwork articles javase index 140168 html March 2003 Online accessed 22 April 2013 Matt Silverman The rise and fall of rim http mashable com 2012 06 25 rim decline chart June 2012 Online accessed 20 April 2013 Craig Walls Spring in Action Manning Publications 2011 ISBN 1935182358 74 10 11 12 13 14 A JAXB Annotations Example First we need to create a data container which will be annotated by JAXB annotations We use a container for simplified scenario information from the EEG Base as visible in Listing 16 The propOrder parameter in the XmlType annotation enforces order of elements in result XML file package data import javax xml bind annotation XmlElement import javax xml bind annotation XmlRootElement import javax xml bind annotation XmlType OXmlType prop rder scenarioId scenarioName XmlRootElement name scenario public class ScenarioSimpleData QXmlElement public int scenarioId XmlElement public String scenarioName Listing 16 ScenarioSimpleData java The next step is to create an instance of the ScenarioSimpleData class fill it with data and unmarshall it into scenario zml Listing 17 75 20 21 22 23 24
58. le to make the framework handle the marshalling unmarshalling process by itself With Spring framework annotations have become a powerful tool which gives us option to handle XML files easily while keeping the code clean with all the semantics in one place An example of creating and reading a XML file using JAXB is available in appendix A 6 3 Apache Maven Maintaining a software project is a significant part of the development process A developer needs to create a project structure take care of required library dependencies deploy a created application and so on Taking care of these operations manually could be difficult but fortunately there is a way to automate them like with Apache Maven 5 Apache Maven depends on its Project Object Model POM stored in a pom xml configuration file It contains projects meta information like 13 Chapter 6 Java technologies a name and parent POM reference library dependency definitions plugin definitions report settings profile definitions and many more Giving the fact that Maven is fully extensible using plugins POM xml content ergo Maven build behaviour depends only on used plugins and their configuration In addition to Maven s extensibility it uses repositories for storing plugins and dependencies It allows companies or individuals to create their own repository in order to keep their own files private or simply to prevent issues related to unavailability of a public r
59. lication can serve as an example The Adapter classes are located in a package named cz zcu kiv eeg mobile base data adapter In case we also want our Adapter implementation to be filterable we must implement a Filterable interface This interface is more usually used over CursorAdapter which uses DB but it is possible to use it over ArrayAdapter too only it is necessary to override more methods keep reference to original data and properly notify about changes For more details see ExperimentAdapter in the EEG Base for Android 12 3 Providing Data Between Activities Passing a primitive data types to another activity is fairly simple we obtain create a Bundle a container for data working like maps into which we put the data set new Intent extras and create the Intent A new Activity in its on Create method extracts the extras Bundle from saved instance Bundle and uses them Retrieving data from an ending activity which was started by the method startActivityFor Result is similar There we override the method onActivityResult where we retrieve the extra Bundle which is provided by the ending activity There is a issue with the complex data types the Bundles are the only efficient way for passing data but they do require a Serializable or a Parcelable interface implemented 41 Chapter 12 Client side II Working with Data Even though the Serializable implementation is more closer to many Java developers we will p
60. lopment A website tool commonly recognized among Android Developers an Android Asset Studio was used for their creation 15 2 Archetypes Project Specifics In the EEG Base for Androids two main archetypes are used CommonActivity and CommonService These two classes are decorated Activity and AsyncTask The CommonService is used for parallel jobs of CommonActivity and both archetypes were primarily created for easy status change from a AsyncTask to a related Activity Also by the time Activity gets destroyed e g screen orientation change existing AsyncTasks may still be running AsyncTasks usually have its ProgressDialog using which is user informed that the application is currently working In order to prevent window leaks the alert dialog must be destroyed and recreated with a reference to a new Activity The CommonActivity and CommonService resolve this issue by using the ServiceReference class which works as a FIFO queue of references to CommonsServices and their messages to ProgressDialog Each time an instance of CommonActivity is created it checks if there is any reference in the FIFO If there are any references all CommonServices in FIFO are set with new CommonActivity reference for context and a new ProgressDialog is created with a proper message Dismissing a progress dialog is also handled If a CommonActivity gets paused the dialog is dismissed If CommonService informs the Activity that the job is done the ref
61. m SDK version value of 15 with possible higher value as target SDK version It is generally recommended to set target version up to the newest version but it is not mandatory Since our application will server as a client for a RESTful web service we need a connection to the Internet In order to provide such connection to our application we must define the following user permissions e android permission INTERNET provides us internet connection in general if it is available e android permission ACCESS NETWORK STATE allows us to check current connection state which is good to know before initiating an web service request there is no point in creating a request if there is no existing network connection If we would need other permissions as well the Android manifest is the place where all permissions are defined 38 Chapter 11 Client side I Creating a New Project Another manifest s block the application block describes the application with its icon label global theme and its components In our application we use Holo theme which is a new standard theme since Android 4 0 x ICS Also since our application does not use content providers services or broadcast receivers only activities will be placed into the application s block body The application itself must have an entry point an activity which is started as a first component of launching application It is set using an intent filter settings bl
62. me screen called Dashboard is displayed to the user 2 Dashboard Welcome to EEG Base This application was created in order to cover basic needs of EEG researchers select from folle Here you can look over basic scenario information and create nev of your own Experiments tion for displaying basic information about experiments and for creating a new o Upload file If you n E Reservations Her a EEG Lab reservatior time for your research team Settings the tings for this application to run properly riment head h tem for creating a r Hopefully you will find this application u I p 2 Dashboard 2 Dashboard EEG Base rto cover scenarios S Experiments following e 1100 reate new Upload file Reservations Settings settings for this application to run proper Hopefully you will find this ation useful a Welcome message b Menu in welcome screen Figure D 2 Dashboard screen The Dashboard shows a welcome message Figure D 2a 83 Appendix D EEG Base for Android User Manual The welcome message contains basic application description and tells the user that in order to switch into another application section he she must use a menu located in the upper left corner of a display as it can be seen in Figure D 2b Scenarios and Experiments sections look very similar except for information they both provide They both allow to fetch records from the server and
63. monServices and will be used in CommonActivities component representing user interface both components will be described further in Chapter 15 Communication between the server and client must be secured Since we use RESTful web service the communication channel will be the HTTPS protocol with SSL encryption A basic overview of components discussed is visible in Figure 9 1 Jetty WebServer Android device EEG Base EEG Base for Android Spring Controller CommonsService HTTPS SSL i h VA DAO Spring Service Commonactivity mi Figure 9 1 Deployment diagram 28 10 Server Side RESTful WS Before we start any work on a client side the server side of a web service must be implemented Creation of a RESTful web service for Java EE application using Spring MVC and JAXB will be discussed in this chapter A reader must be aware of Java EE basics in order to understand the following text For handling of a HTTP request we use a Spring MVC component of Spring framework 10 1 Messages Only rarely is returning or obtaining of primitive data types sufficient for a whole RESTful web service unlike the complex types handling In order to provide complex types from the server to the client and vice versa data containers have to be transformed into XML or JSON
64. n for XML is represented by MarshallingView It uses internally a JAXB marshaller Jaxb2Marshaller Inside the JAXB marshaller bean we define all marshallable data containers into a list of property named classesToBeBound By enumerating the data containers we tell Spring that instances of such classes should be automatically marshalled and unmarshalled without the need of using ResponseBody annotations By now we need to allow Spring MVC annotations and define package in which are present annotated classes We achieve it using the following lines lt mvc annotation driven gt lt context component scan base package cz zcu kiv eegdatabase webservices rest gt Listing 2 Enabling MVC annotations in cz zcu kiv eegdatabase webservices rest package 10 2 2 Controller Spring MVC provides controllers special components meant for handling HTTP requests Such components can be created either using XML definitions and by extending a proper abstract class or using Controller annotations Controlling HTTP requests we can cover all RESTful web service requirements In order to control HTTP requests we need to create mapping over specific URL and handle it by controller s method The Request Mapping annotation over a method makes the method listen on the URL specified in annotations value property By default such mapping applies to GET HTTP requests if we desire to handle other HTTP methods we need to specify it by method property
65. n the user and ready to be used When an application provides to user such possibility which extends and improves user s usecase we speak of this possibility as of a service Modern application often provides many separate services which are joined as modules of an complex and sophisticated application Every service provides its public interface by which it is available for user so a client application could access it and use it for its purpose This approach of application design is recognized as SOA service oriented architecture and application developed this way is by definition service oriented This thesis is dedicated to provide a solution for a need of EEG researchers to have a quick simple and accessible way to obtain basic information about their experiments and to store measured data when measuring computer does not dispose of internet connection while their mobile devices do Chapter 1 Introduction The theoretical part of this thesis analyses requirements originated from such needs submits solutions and explains the features of chosen solution Specifics and basic description of required technologies are also presented in this part The following part of practical realization puts its focus on description of development process of an Android client application service oriented server side and also submits means to develop own application The last part of the thesis presents testing results proposes ideas for futu
66. nager instance The methods of such trust manager are empty only the X509Certificate array getter creates a new empty array of such data type e SecureRandom null The Rest Template using this custom client http request factory will accept all SSL certificates over HTTPS protocol 13 2 Direct Usage of Rest Template As well as in the EEG Base for Android we will presume that the RESTful web service on the server authorizes requests which do have set a HTTP header parameter of HTTP Basic Authentication It is sufficient in case that the server uses Spring Security Let us present an example of a remote creation of new user which will represent the approach for client server communication in general other cases are very similar First we need to define a request s HTTP header The header is represented by HttpHeaders instance and in it we must define the following HTTP header parameters e Authentication Here we use HTTP Basic Authentication by creating a HttpBasicAuthentication instance Into this instance are set username and password e Acceptable response content types A collection of acceptable response types belongs here Since our web service communicates only using XML messages we put here a list with only item of APPLICATION XML string e Request content type As well as for response we must define of what content type is our request In this example we create a new user which is represented by XML message APPL
67. ng in setUp test stage as shown in Listing 15 Although there is a security risk in putting user credentials available in a plain text this is the only solution which was found and resolves the issue A possible solution might be reading credentials from a properties file where they would be set only in case of testing or to create an account for testing purposes Before public void setUp throws Exception Person user personDao getPerson petrmiko students zcu cz List lt SimpleGrantedAuthority gt authorities new ArrayList lt SimpleGrantedAuthority gt authorities add new SimpleGrantedAuthority user getAuthority Authentication auth new UsernamePasswordAuthenticationToken user heslo authorities SecurityContextHolder getContext setAuthentication auth Listing 15 Manual logging in within Junit 4 test Client side communication was either tested continuously during development and during user testing Following scenarios were created for user testing 1 Log into application 2 Display details of public scenario 3 Create experiment with a new electrode location 4 Upload file to a newly created experiment These scenarios were performed by the following users while their overall satisfaction marks are noted in Table 16 2 Scaled on range of 1 as the lowest to 10 as the highest satisfaction with the application 63 Chapter 16 Testing Gender Age Pros Mark
68. nu menu 3 super onCreate ptionsMenu menu 4 MenuInflater inflater getMenuInflater 5 inflater inflate R menu exp_menu menu 6 return true 7 Listing 9 Example of inflating menu resource in Experiment Activity Now we have an inflated menu which has its menu items Each menu item has its identifier which is used in event handling method for event source recognition The event handling method is called onOptionsItemSelected In order to handle events over our menu resource we must override it and alter its behaviour 1 QO0verride 2 public boolean onOptionsItemSelected MenuItem item 3 switch item getItemId 4 case android R id home 5 finish 6 break 7 other cases distinguished by identifiers 8 9 return super onOptionsItemSelected item 10 Listing 10 Example of handling menu items events Note the android R id home identifier This is an identifier for a special 47 Chapter 14 Client side IV Navigation button a home button located instead of activity s icon which has the icon as its contents but right next to it is a lt character This button is meant for going up in the logical hierarchy of screens Imagine the situation when you were in a list view of records and you clicked on record A details activity was displayed but you clicked on a button which took you to page 2 The back button would take you to page 1 but the home button with a proper implementation
69. ock of an activity In this block are specified an action MAIN and a category of such intent LAUNCHER While all components inherit a theme and UI options settings from its parent i e the application block these settings may be changed in each component That is important for components whose behaviour should be different from other components Let us present some examples which are also used in the EEG Base for Android e android theme android style Theme NoDisplay Activity with this parameter will not display any layout Such behaviour is desirable in an application entry point where we check whether the user is logged in so we let him her further into application or we enforce user s log in e android theme android style Theme Holo NoActionBar ActionBar is a new central place for putting application s controls since Android ICS But in some cases it is required to the ActionBar would not be displayed This parameter provides such behaviour e android uiOptions splitActionBarWhenNarrow There is a difference between layouts for hand held devices and tablets Even though custom layouts provide most of the customization sometimes is desirable that ActionBar s controls display in separated menu bar in the bottom of the screen Such behaviour is achieved using this parameter For further implementation details of manifest used in the EEG Base for Android head for the manifest file located in project s directory on attached
70. on and provides required data synchronization While creating an application the EEG Base for Android a lot of effort was focused on simplicity of software project management Therefore a Apache Maven was used for clear definition of a directory structure simplicity of dependency management and building the client application itself Both the client side and the server side can be easily extended for further logic in future as suggested in Chapter 17 67 List of Figures 4 1 5 1 6 1 dsl 8 1 8 2 9 1 14 1 14 2 15 1 15 2 15 3 15 4 15 5 D 1 D 2 D 3 D 4 D 5 D 6 EEG Database client application use case diagram Communication diagram between web service elements 3 Maven Directory Structure 2 2222 cols Android OS versions market share in April 4th 2013 Resource selection flowchart 12 Example of strings xml structure Deployment diagram svi os pira de a ie e Android project on disc file structure Tabs as a navigation menu in the EEG Base for Android Spinner navigation menu in EEG Base for Android Activity diagram of application startup Activity diagram of WelcomeActivity Activity diagram of NavigationActivity Activity diagram of activities with tabs for record browsing Activity diagram of DataFileUploadFragment a Loss tok of Gen ee s do PEE ae Dashboar
71. orm 7 5 Selection Decision Following platform selection criteria were established e well documented API e free SDK e development platform independence e large market share of mobile platform Although iOS provides free SDK for universities Objective C is not a common programming language and considering the current price of any Apple mobile device it is not expected that an EEG researcher would be equipped with it For both Windows Phone and BlackBerry applies that although they represent an interesting piece of technology their market share is not large enough to pay attention to them as a primary application platform However that may change in time yet for Windows Phone there is still a limitation to the Microsoft Windows operation system Respectively for aforementioned issues of other platforms Android was selected as a development platform In addition Android has the following benefits e Free everyone can develop their application without payments e No registration needed the developer does not need to create any account to access the SDK e Multiplatform development Android SDK is available for Windows Mac and Linux equally 20 Chapter 7 Mobile Platforms Moreover Android of SDK v15 4 0 x was chosen for development since this version and higher ones represent majority in Android platform see Figure Market share Android s market share is one of the largest and it still keeps growing
72. ormed in parallel to the GUI thread should be done here e onPostExecute final steps before Async Tasks ends Method runs on GUI thread in order to reflect results into it The AsyncTask components are more suitable for short operations which directly affect flow of application GUI As an example of the situation suitable for an AsyncTask is fetching data which should be displayed right after they 26 Chapter 8 Android Specifics are available The data fetching would be performed in parallel to the GUI thread so it would not freeze and would be updated by AsyncTask when the job is done Only drawback worth mention is that due to its reference towards currently visible activity the AsyncTask must be handled when the activity is being destroyed otherwise there will occur an error once the AsyncTask attempts to access the GUI thread 8 2 3 Service Services like activities hold own context but they are running outside the GUI thread They are primarily meant for performing operations independent of the rest of application s flow like downloading of large files which can run independently of the rest of the application Because Services are not used in this thesis application its methods will not be further discussed 8 3 Manifest File An Android manifest is a file gathering essential information about an application through its properties and components It is a specifically formatted XML file into which develope
73. ource but unlike WP is used only on Apple s devices no other hardware manufacturer but Apple creates iOS powered mobile devices Although iOS devices do not belong among the cheapest ones thanks to them Apple nowadays competes with Google s Android operation system for majority in mobile devices market iOS is an operation system derived from OS X which is an Apple s operation system for their computers and laptops As a primary programming language for application development an Objective C is used in which is also created Cocoa Touch API 14 an UI framework for building software applications for iOS platform Current devices are equipped with iOS 5 released in 2011 and iOS 6 released in 2012 Strengths e Loyal user base almost no piracy users tend to buy applications e Clear application guidelines a developer can learn best practices from a reliable source e Support Apple provides thorough support in return to annual payments Drawbacks e Necessity to comply to the application guidelines if not conforming to them application is refused to App store e Annual payments developer not willing to pay is not able to develop applications 17 Chapter 7 Mobile Platforms 7 3 BlackBerry BlackBerry devices were for a long time a clear choice for a corporate segment of market Their creator the BlackBerry company former Research in Motion RIM have lost in past four years 20 many of its former c
74. pecial Spring context file is required This context file initializes database connection and other vital Spring components beans transaction manager The context loading is managed by code shown in Listing 14 which is placed above the class body 1 RunWith SpringJUnit4ClassRunner class 2 ContextConfiguration locations classpath test context xml Listing 14 Class annotations for loading Spring context Creating a new record was tested in unit test methods as well as checking its presence in the output of getter methods CR In case of getter methods was checked if content of service core method matches the data available through DAO objects R Table 16 1 Data type Test cases Results Artifact CR OK Data File CR OK Digitization CR OK Disease CR OK Electrode Location CR OK Electrode Fix CR OK Experiment CR R public records R user s records OK OK OK Person R login R all records OK OK Research groups R public records R user s records OK OK Scenario CR R public records R user s records OK OK OK Table 16 1 Unit tests in accordance to data types and their results 62 Chapter 16 Testing Table 16 1 represents a brief summary of performed unit tests and their results Tests themselves are represented by methods annotated with the Test annotation over them However in some test cases a logged user was required It was resolved by manual loggi
75. r as the XML definitions is the annotation way of implementation used in this thesis unless the XML variant would significantly benefit us over the annotations 12 Chapter 6 Java technologies 6 2 JAXB XML manipulation is one of the most performed operations nowadays more importantly due to web services whose communication is basically built on XML technology Java Architecture for XML Binding is a framework for simple manipulation with XML in Java and can be simply described as ORM for XML The framework does most of the XML heavy lifting for user in a way that the user does not need to know anything about differences between SAX and DOM parsing 19 With JAXB technology the user defines or specifies a XML schema by which is performed so called binding It means that for specified XML schema are generated Java classes which are afterwards used for reading existing XML files in a process called unmarshalling The opposite process when we store initialized objects of binded classes is called marshalling Basic usage assumes a XML schema defined in a XSD file for which are generated Java classes using JAXB libraries The libraries are available either in JDK 6 and higher or stand alone for separate download and usage Another option is to define the XML schema in a Java code by a developer using annotations Marshalling and unmarshalling is by default handled by a developer s code but with technologies like Spring it is simp
76. r declares an Android SDK version permissions used activities services content providers etc It is necessary that developers define all possible information into the manifest Using the Android Manifest devices check whether they are capable to run the application and request proper rights from user Also without records about used Android application components i e Activities Services Resource providers and Broadcast Receivers application cannot run properly An error is raised if application tries to access a component not mentioned in Manifest file 24 9 Architecture In the following chapters we will focus on a server side and a client side implementation of the RESTful web service But first let us take a look on architecture of such implementation Data which are needed on client side are already available in the EEG Base they only need to be handed over to the client on request Therefore we implement controllers which handle HTTP requests Spring Controllers and a component which will fetch data from the existing data layer Data Access Objects into a transferable format and which will be available through the controllers Spring Services All components on the server must use existing technologies Using Spring IoC and MVC is an ideal choice which also define its architecture due to dependency injection On the client side we implement logic for client server communication Such logic will be present in Com
77. re application enhancement and submits the thesis conclusion 2 EEG and ERP In matter of recording brain activity there are two possible approaches A first approach is obtaining a record using an electroencephalogram in an diagnostic procedure called Electroencephalography EEG This method provides non invasive and relatively cheap way to measure an active electric potential of brain cells Even though this method is usable for diagnosing diseases like epilepsy or recognize brain death its drawback is that the record is a mixture of hundreds different neural signals in which might be difficult to recognize specific neuro cognitive processes A second possibility is a derivative of EEG measurement ERP measurement in which we seek for Event Related Potentials Event related potentials are measurable electric potentials created in reaction to a stimulus of sensory origin like touch smell or sight Stimuli might be both of conscious or unconscious type while the stimuli response might be usually more distinctive to observe in the recording when a tested subject does not expect the stimuli to come Such fact is often used when measuring stimuli response called P3 or also P300 Such potential has positive voltage deviation and occurs right about 300 milliseconds after stimulus Also ERP potentials are measured locally at desired brain cortex while EEG itself represents a global method of measuring the brain activity 3 EEG Base EEG
78. researchers gather files which need to be uploaded we must be abble to provide such logic File upload takes place in two places in ScenarioAddActivity class and DataFileUploadFragment class In case of scenarios we upload files only when creating a new scenario record In case of data files we can upload them only to existing experiments from 59 Chapter 15 Client Side V EEG Base for Android Specifics the NavigationActivity In both cases we need to select a file to be uploaded Because Android does not provide any file browsing component a FileChooser Activity was created for these purposes It is a list view which fills FileInfo instances as its rows On an item click event we return to caller activity The process of uploading a data file is visible in Figure 15 5 Inflating layout Ul ready File selected vai Control selected File selection Starting FileChooserActivity Displaying dialog with errors Upload Input validations Yes Errors V NS Starting upload Commonservice gt Figure 15 5 Activity diagram of DataFileUploadFragment 15 5 6 Settings Settings are simple custom implementation of SaveDiscardActivity which serves for making changes in credentials shared preferences It provides means to edit username password and web service URL Moreover there is a feature that enables to set Monday as a first day of week It is useful for choosing a date in DatePicker component on t
79. researchers produce large amount of recordings and related meta data during their experiments like specific measuring scenario details description of a measured subject etc The EEG Base is a web portal created in order to provide a complex database for gathering such information while extending researchers possibilities in manner of sharing stored information between each other inside the scope of the EEG Base The functionality of the EEG Base has been incrementally improved and extended Besides storing data and meta data the EEG Base now provides methods for processing stored experimental data and disposes of SOAP web services for third party application access Also each user of the EEG Base is affected by rights that are assigned to his her account that ensures user can access data which are either public or to which user participates Technologically the EEG Base is a Java Enterprise Edition application which uses frameworks as Spring Hibernate Apache CXF etc The portal is being developed under supervision of Roman Mou ek Petr Je ek and Petr Br ha in cooperation with students who may gain useful knowledge of current software development technologies by participating on the development process The portal identifies itself with an INCF International Neuroinformatics Coordinating Facility effort in the development and standardization of neuroinformatical databases 4 Requirement Analysis An experimenter uses a per
80. resent here an implementation example for the Parcelable interface The Parcelable interface was designed specially for Android and should be more efficient In an parcelable class a developer must implement its own serializing during which we work with a Parcel instance which works similar to a Bundle The important thing is to keep the same order of reading from a Parcel instance as it was in case of writing to the Parcel otherwise the serializing will not work Also in order to keep Android designs we must create a public static Parcelable Creator which is used for recreation of the data contained in other parcelable containers An example can be seen in Appendix B 42 13 Client Side 111 RestTemplate 13 1 Communication Using HTTP SSL In order to provide secure connection with server the HTTPS protocol must be used with SSL encryption But once such combination is used a client application must be edited so that it would be capable to communicate with the server over the secured communication channel Our application will discuss the case when the application will accept all certificates used for communication The reason for such implementation might be various from creating a functional prototype to simply not having an official certificate for communication encryption while this should be a temporary solution like it is in the case of the EEG Base While many examples use in Rest Template for the communication
81. ription Figure D 4 Filtering fetched records The record s details may contain list of secondary information like a list of electrode locations If there is such a list any item can be clicked on in order to display a dialog window with further information Now let us focus on creating new records Both in scenarios and experiments section there is a related button in action bar for creating a new record It has an icon with plus symbol and it opens a new activity screen Inside this new screen we must fill all the required fields otherwise application will show dialog with error message describing what is missing 85 Appendix D EEG Base for Android User Manual In case of a scenario type a file from the device s file system must be selected In order to select the file we must click on a button with a directory icon a file browser is opened Figure D 5a When a file is selected the file browser is closed and user may save the record An example of filled information with the selected file for upload can be seen in Figure D 5b The record is saved by clicking the Save button or discarded by the Discard button a File browser b New scenario creation screen Figure D 5 Creating new scenario In case of experiments we must first wait till required data are fetched from the server Creating a new experiment is a complex operation which requires a lot of additional information Figure D 6a W
82. rviceState which holds enumeration of possible CommonService states and Values which serves as a container of various constants and values like RESTful web service endpoints flags and keys for activity results etc Other classes are in the following sub packages 15 3 1 Container Simple data containers were created in order to contain available data The containers are Parcelable and they can be used for XML marshalling and unmarshalling in Rest Template thanks to Simple Framework annotations The matter of Parcelable was discussed in Section 12 3 and an example of such parcelable and marshallable container can be seen in Appendix B Such containers are created for all required data types e g artifacts experiments electrode locations etc The mentioned containers are placed into a xml sub package since there is an exception in FileInfo container This class is a simple decoration of a Java File class which provides file s size string in human readable form and it is used in application s file system browser The FileInfo class is not marshallable nor parcelable since it is limited to local files and the objects are not passed to Bundles 93 Chapter 15 Client Side V EEG Base for Android Specifics 15 3 2 Adapter Since the EEG Base for Android requires a custom behaviour of spinners list views and other similar components there must be created custom ArrayAdapters as well These adapters are located in the adapter data
83. sers with tablets so there would be extended date pick dialog which are used to such calendar layout 89 Appendix D EEG Base for Android User Manual JX DISCARD Username petrmiko students zcu cz rd URL https 192 168 88 138 8443 rest Monday as first day in week Figure D 9 Settings 90
84. setup process is described in the Tomcat server manual In web application it is necessary to define a security constraint over a URL pattern within the web xml as in Listing 7 lt security constraint gt lt web resource collection gt lt web resource name gt Spring REST SSL lt web resource name gt lt url pattern gt rest lt url pattern gt lt web resource collection gt lt user data constraint gt lt transport guarantee gt CONFIDENTIAL lt transport guarantee gt lt user data constraint gt lt security constraint gt Listing 7 Forcing secure channel for RESTful web services in web xml 34 Chapter 10 Server Side RESTful WS With these settings each time a request to http app domain rest is created it will be redirected to https app domain secured port rest It is thanks to a transport guarantee parameter which enforces usage of protected transport layer connection HTTPS and its CONFIDENTIAL parameter which requires communication encryption 18 35 11 Client side I Creating a New Project Throughout this chapter we will focus on creating an Android application and on implementation parts which are generally applicable to other applications However the examples will be applied to the EEG Base for Android which is official name for the Android based client application on device named as the EEG Database which was created for resolving needs mentioned in Chapter 4 11 1 Creating Andro
85. sonal computer for his her work with special hardware peripheries like EEG caps or Brain Vision recorder There must be clearly defined scenario and described a set of used hardware for experiment itself in order to repeat such experiment Also information about a tested subject is required besides usual information of name and surname is relevant if the subject is left handed currently suffering from some disease etc Environment in which the experiment is conducted is relevant too Its description must be made and preserved All these pieces of information and even more must be stored as well as the experiment recording itself EEG Base mentioned in the previous chapter serves for this purpose Most of the time might be sufficient to use the very same personal computer as for conducting the experiment but there are at least two valid situations when using a computer is not a viable option 1 Computer is not connected to the Internet Computer dedicated for conducting experiments may not dispose of internet connection Assuming that other members of research group are depending on experiment results and are not currently present there arises a problem with delivering the data towards them 2 Need of quick access to existing information Researchers may be out of reach to computers in need to quickly access some specific basic information about their experiments and scenarios e g during a conference If there is no viable alternat
86. splay them in a component meant for such purposes a list view A ListView by default displays only a string per view item which is not enough for reasonable display of a complex type record In order to change the way the ListView displays related data we must implement own Adapter 40 Chapter 12 Client side II Working with Data There are multiple provided implementations of Adapters and in our case we use an Array Adapter implementation We must create a custom class which uses the Array Adapter as a parent and inside of class implementation we override desired methods which affect the Adapters behaviour The most likely methods to be overridden are methods get View and getDropDownView The first one is used for usual displaying all items into view elements visible at activity start like the ListView the second one is used in view elements using drop down behaviour like Spinners Since both methods have identical parameters their behaviour can be covered by a common method which initializes view element with requested data and returns it The initializing method reads data from a provided data collection by requested position then initializes a new element s view sets the data to it and returns the prepared element view The common approach for creating an Adapter is creating a reference to a proper row layout which is inflated and then set with data in an initializing method Any Adapter in the EEG Base for Android app
87. sts class This class contains methods methods into which we provide only frame layout and a collection with data the rest is handled by the class s methods 15 5 4 Creating a New Record In all aforementioned sections reservations experiments scenarios we can create new records In general there is a SaveDiscard Activity whose layout contains all required input fields When they are filled user confirms the data proper CommonsService related to the data type is triggered and the record is created These activities also provide created record as a result to previous activity in order to add it into its array adapter From ExperimentAddActivity or ScenarioAddActivity we can also create records of data types which do not have its section for browsing but which are available for purposes of a new complex type creation Such data types are people artifacts digitizations diseases electrode fixes locations and types and weather types All data types have its container which is used in the name of an activity for creation of such record The naming convention for these activities is lt Container gt AddActivity The last creatable record is Reservation which represents booking time to the EEG Lab at the University of West Bohemia The difference against other data types is that these records can be removed from the application if they are owned by user or the user is an administrator 15 5 5 Choosing File for Upload Since EEG
88. sub package and provide view elements in accordance to provided data containers and related row layouts as discussed in Section 12 2 15 4 Web Service Communication All the knowledge about RestTemplate and SSL connection from Chapter 13 is used in CommonService implementations which are located in the cz zcu kiv eeg mobile base ws asynctask package Each CommonService implementation s name consists of an action prefix which tells us what a service does like create or fetch and the related data container It means that CreateWeather class serves for creating a new Weather record on the server while the FetchArtifacts class retrieves from the server a list of all existing artifacts As every Async Task CommonService is an AsyncTask with decorations these classes operate both with the GUI thread and on background without it see Section 8 2 2 All the client server interaction takes place in the doInBackground method where we initialize a RestTemplate instance and perform a required operation like shown in Listing 8 Almost all CommonServices are fairly simple to understand to since they exchange only one instance of marshallable container at the time This does not apply to the CreateScenario and UploadDataFile classes which must upload an existing file from device s file system as well as required meta data Since we use Spring MVC on the server and Spring s Rest Template on the client the solution is simple as well On the cl
89. tch Figure 8 1 Resource selection flowchart 12 8 1 1 Application Localization When writing an Android application it is most recommended to avoid using hard coded strings and use Android s references to string resources instead These resources are located in values directories in strings xml files The plural is used intentionally because it can be easily distinguished which strings should be used by specifying locale qualifier in values directory name 23 Chapter 8 Android Specifics The locale is distinguished by a two letter language code ISO 639 1 which might be optionally followed by a dash and two letter region code ISO 3166 1 alpha 2 like de for German ja for Japanese etc It means that texts in German should be located in resource file values de strings xml The same logic applies to other languages Each string in strings XML resource file is an application string resource String of an application name could be stored like in Figure 8 2 and then referenced in a code by its name app name resources string name app_name gt EEG Base lt string gt lt resources gt Figure 8 2 Example of strings xml structure 8 1 2 Application Layouts With Android devices supporting a large scale of devices with various screen resolutions and densities developers must adapt their applications so they work correctly on all of them Obviously an adapting application layout is inevitable in order to provide
90. urce XML file with menu items defined in it 9 Both activities and fragments can present own options menu items which are merged into one common menu All items are hidden in menu by default If we want to see them on the ActionBar we must set the item s showAsAction attribute Possible values for this attribute are e always will be visible under all circumstances recommended max for 2 menu items e ifRoom visible on the ActionBar only if there is a free space e withText shows item s title even if there is an icon set e never item will be always inside the options menu and not in the ActionBar e collapseAction View when a menu item is clicked on its view expands all over the ActionBar This behaviour is quite useful for implementing a search text box like in List AllExperimentsFragment class in the EEG Base for Android 46 Chapter 14 Client side IV Navigation Now let us see how implement option menus in activities and fragments 14 1 1 Activities Implementing option menus in activities is fairly simple the only things need to do are inflating the menu and handling item selection events The menu is being inflated in the method onCreateOptionsMenu Here we obtain a MenuInflater instance and inflate proper menu XML resource into provided menu instance It is crucial to return true after the job is done otherwise activity will ignore our menu settings 1 QO0verride 2 public boolean onCreateOptionsMenu Me
91. ustomers due to far too long development process of new BlackBerry 10 OS BlackBerry 10 OS was finally released in early 2013 and hopes to regain its slice of mobile device market A new BlackBerry platform provides the largest scale of available development languages and frameworks A developer can use native C C SDK with Qt for a user interface or he she can develop applications using Adobe AIR HTML5 or even repackage existing Android application 1 While BlackBerry now seems to be as a perfect choice for power users and developers who want to try a new technology its market share is so unsignificant that probably only the corporate segment can make Blackberry significant once more Strengths e Many ways to develop an application C C with Qt or QML HTMLS Adobe AIR e Corporate customers based on BlackBerry s past and sofisticated security could be expected that the BlackBerry platform will be vastly used in the corporate segment once again This strength could be applied to applications primarily developed for corporate environment Drawbacks e Market share BlackBerry had significantly dropped its market share in past few years and BlackBerry 10 OS is a brand new platform e Number of devices only few devices using new BlackBerry OS so far 7 A Android Android is an open sourced platform using Linux operation system inside of which a Dalvik process virtual machine a Java based sandbox for Android
92. vices Description Language XAML Extensible Application Markup Language 71 List of listings XML Extensible Markup Language XSD XML Schema Definition 12 Bibliography 1 BlackBerry Develop with blackberry http developer blackberry com develop 2013 Online accessed 28 April 2013 2 Dieter Bohn Android device diversity and fragmentation charted in minute detail http www theverge com 2012 5 15 3023119 android device diversity fragmentation chart May 2012 Online accessed 29 April 2013 3 Peter Brittenham An overview of the web services inspection language http www ibm com developerworks webservices library ws wsilover June 2002 Online accessed 16 April 2013 4 Roy Thomas Fielding Architectural styles and the design of network based software architectures http www ics uci edu fielding pubs dissertation top htm 2000 Online accessed 16 April 2013 5 The Apache Software Foundation Apache maven website http maven apache org unknown Online accessed 25 April 2013 6 Google Platform versions http developer android com about dashboards index html April 2013 Online accessed 7 April 2013 7 Google Fragment documentation http developer android com reference android app Fragment html unknown Online accessed 27 April 2013 8 Google Layouts http developer android com guide topics ui declaring layout html unknown Online access
93. vider A hardware or software unit providing the web service itself accessible by endpoint URL e Service Requestor A subject requesting a specified web service gt a client application which uses a code generated from WSDL 5 2 RESTful Web Services Representational state transfer is a architectural style for developing applications which is specific by a set of constraints as mentioned in 4 Chapter 5 Web services SOAP and REST e Client server separation of concerns a server does not need to handle GUI or an application state In combination with a uniform interface this results in platform independence allows better client scalability and server side itself is much simpler e Stateless client server communication is in REST stateless so every request from client to server must contain all necessary information Keeping of state belongs to the client side e Cachable data within responses must be labeled whether they are cacheable or not so client application could reuse them by saving them into a cache for further use It lowers a necessary number of interactions and bandwidth usage overall e Layered system a client does not need to obtain data precisely from the requested location the requested location might be an intermediary which works as a client itself upon other nodes in the network This may if well designed improve scalability due to possible load balancing while using previously mentioned cac
94. with the server a CommonsClientHttpRequestFactory class this class has a huge drawback it cannot send a file without buffering it into memory first In case of large files it leads to out of memory errors which makes this class not usable for our web service client Instead we create own HTTP request factory class which will accept all SSL certificates and will be also useful for RestTemplate It will extend a SimpleClientHttpRequestFactory class from the Spring Framework http client package An instance of this class can disable the content buffering prior send by setting a false value into setBufferRequestBody method This class should be available in project since we have a dependency of the Rest Template defined in project s POM file In this new class we have to override the method openConnection which will decorate the parent s method by setting the HostnameVerifier instance which accepts all hosts simple interface implementation which returns true in its only method and setting a custom SSL Socket factory to a HttpUrlConnection instance which was first casted to a HttpsUrlConnection instance The custom SSL Socket factory is obtained by a getter from a SSLContext TLS instance which was initialized with parameters lez zcu kiv eeg mobile base ws ssl SSLSimpleClientHttpRequestFactory 43 Chapter 13 Client Side III RestTemplate e KeyManager null e TrustManager implementation returning a X509TrustMa
95. you can either install the application as described in Section C 2 or the install application using Maven In order to install the application using Maven enable USB debugging in System settings gt Developer options When set type and confirm following snippet in console It installs the application and starts it once it is installed mvn android deploy android run C 2 Install from APK In order to the install application directly from the APK file we need to enable the Unknown sources item in System settings gt Security Now there are two possible ways to install the file Either copy APK file into device MTP protocol mount phone as USB storage or just send it to yourself by a mail and start it or enable USB debugging and use ADB application from Android SDK if you have it on your computer adb install eeg base apk 8l D EEG Base for Android User Manual The application is started by clicking on EEG Database icon in device s main menu If the application is started for the first time a log in activity screen will be presented to user Figure D 1 O EEG Database toc EEG Database students zcu cz https Figure D 1 Log in screen When the user successfully logs into the application with own EEG Base 82 Appendix D EEG Base for Android User Manual credentials and proper service URL testing server https 147 228 64 172 8443 was used during the thesis implementation the welco

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