Overcoming Device Fragmentation Problems with J2ME Polish
Introduction J2ME Polish
Mobile Technologies Java Technologies
Overview ●
●
There are many different, competing mobile technologies Most widespread technology is mobile Java (Java ME / J2ME)
●
How to overcome problems with J2ME?
●
Introducing J2ME Polish
●
Showcase: mobile Wikipedia
Synyx GmbH & Co. KG ●
Founded 2002
●
Specialized in developing OpenSource Solutions
●
Specialists for Java from EE via SE to ME and FX
●
23 Employees
●
Localized in the center of Karlsruhe
Thomas Kraft ●
Co-Founder of Synyx GmbH & Co KG
●
Worked actively in several mobile technologies
●
Open Source enthusiast
●
Wrote several Articles about J2ME Polish
●
Co-Author of J2ME Polish book
Rainer Steinegger ●
J2ME Specialist at Synyx GmbH & Co. KG since February 2006
●
Teaches Mobile Development at Oberstufe
●
Studies Computer Science at HS Karlsruhe
Introduction J2ME Polish
Mobile Technologies Java Technologies
Mobile Technologies Overview ●
Textmessaging SMS
●
WAP / Web
●
Java
●
BREW
●
Flash Lite, Silverlight, Java FX
●
●
Operating Systems: Symbian, Windows Mobile, Linux, Apple OS X Further Proprietary Technologies (mostly player based)
Mobile Technologies ●
What Technology Should I Use? –
Market Reach
–
Required Interactivity
–
Online / Offline Functionality
–
Availability of Developers
–
Developer Tools
–
Runtime Speed
–
Project Specific Requirements
–
Fragmentation
–
...
Fragmentation ●
Mobile device fragmentation limits mobile application adoption and thereby Carriers’ ARPU growth –
Different hardware
–
Different API Support
–
Different interpretations of standards
–
Device bugs
Mobile Technologies Overview Market Reach SMS WAP/ Web Java BREW Flash Lite Symbian etc
Interactivity
Online/ Offline
Availabil Dev. ity of Tools Dev.
Speed
Fragmen tation
Introduction J2ME Polish
Mobile Technologies Java Technologies
Java Technologies ●
Java EE: Enterprise
●
Java SE: Desktop
●
Java ME: Mobile
●
Java Card: Smart Cards, SIMs
Mobile Java Success Story ●
●
●
More than 500 billion Java enabled mobile handsets used worldwide Approximately 80% of all handsets shipped with mobile Java support in 2007 Open API extensions provide quick adoption rates for new technologies
Mobile Java Technologies ●
Java ME CLDC + MIDP + Optional APIs
●
WIPI
●
DoJa
●
BlackBerry
●
Google Android
Mobile Java Development Life Cycle ●
Idea
●
Conceptual Design
●
Implementation –
programming: NetBeans, Eclipse, J2ME Polish
–
debugging: WTK, Vendor Specific Emulators
–
styling: J2ME Polish
●
Porting: J2ME Polish
●
QA on real handsets
●
Deployment –
OTA
–
Bluetooth
MIDlet Life Cycle ●
MIDlets are the entry points for applications
●
Lifecycle
●
–
Create in the constructor
–
(Re)Launch of application in startApp()
–
Pause of application in pauseApp()
–
End of application in destroyApp()
public class MyMidlet extends MIDlet { public MyMidlet() {} public void startApp() { Display display = Display.getDisplay(this); display.setCurrent( getStartScreen() ); } public void pauseApp() {} public void destroyApp( boolean force) {} public List getStartScreen() { List list = new List("Main", List.IMPLICIT); list.append("Start", null); list.append("Help", null); list.append("Exit", null); } }
Challenges for Mobile Projects ●
Device Fragmentation
●
Resource Limits
●
–
Memory consumption
–
JAR size
–
Speed
Design –
High Level vs. Low Level GUI
–
Adjusting resources / Customization
Introduction J2ME Polish
Mobile Technologies Java Technologies
Structure of J2ME Polish ●
Device Database
●
Build Framework
●
Client API
Build Framework
Client API
Device Database
●
Further Components: –
Tools
–
IDE Integration
Device Database ●
●
Device definitions as the foundation
Build Framework
Client API
Detailed information Device Database about J2ME capable devices - APIs, certificates, screen resolutions, known issues, ...
●
Used by the Build Framework and the Client API
●
XML based: easy extensible, web based
Build Framework ●
● ●
●
Automates necessary steps for creating J2ME apps
Build Framework
Ant based Can be integrated into any IDE
Client API
Device Database
For every target device:
Preprocess
Extensible Compile
Package
Finalize
Emulate
Client API ●
●
GUI: Lush –
Design outside of the application using CSS
–
Non standard screens and items
–
Uses Device Database and Build Framework for adapting and customizing
Device Database
Persistence: Trunk Easy serialization and storage
Server Client Connectivity: Touch –
●
Client API
–
– ●
Build Framework
compatible to MIDP 2.0
RMI, XML-RPC, HTML and RSS support
Utilities –
ArrayList, HashMap, IntHashMap, Locale, RgbImage,
Step 1: Programming the MIDlet ●
Basic MIDlet Structure package de.enough.polish.sample.wikipedia; import javax.microedition.lcdui.*; import de.enough.polish.browser.html.HtmlBrowser; import de.enough.polish.event.ThreadedCommandListener; import de.enough.polish.ui.UiAccess; import de.enough.polish.ui.splash.ApplicationInitializer; import de.enough.polish.ui.splash.InitializerSplashScreen; public class WikipediaMidlet extends MIDlet implements CommandListener, ApplicationInitializer { private static final Command CMD_MAIN_MENU = new Command("Main Menu", Command.BACK, 5 ); private static final Command CMD_BACK = new Command("Back", Command.BACK, 5 ); private static final Command CMD_EXIT = new Command("Exit", Command.EXIT, 10); private static final Command CMD_GO = new Command("Go", Command.OK, 2 ); private Display display; private Form browserScreen; private HtmlBrowser htmlBrowser; private List mainMenu; private String defaultUrl = "http://en.wikipedia.7val.com/j2mepolish?startpage=long"; private Form settingsForm; protected void startApp() throws MIDletStateChangeException { // show splash screen during start up } public Displayable initApp() { // application is initialized here } protected void pauseApp(){ // app is paused } protected void destroyApp(boolean unconditional) throws MIDletStateChangeException { // nothing to clean up } public void commandAction(Command command, Displayable displayable) { // commands are handled here }
}
Step 1: Programming the MIDlet ●
Initialization protected void startApp() throws MIDletStateChangeException { this.display = Display.getDisplay(this); if (this.mainMenu == null) { try { Image splashImage = Image.createImage("/splash.png"); InitializerSplashScreen splashScreen = new InitializerSplashScreen(this.display, splashImage, 0xffffff, null, 0, this ); this.display.setCurrent( splashScreen ); } catch (Exception e) { //#debug error System.out.println("Unable to create splash screen" + e); Displayable disp = initApp(); this.display.setCurrent( disp ); } } } public Displayable initApp() { //#style screenMain List menu = new List("Wikipedia Menu", Choice.IMPLICIT); //#style itemMain menu.append("Quick Launch", null); //#style itemMain menu.append("Search", null); menu.addCommand( CMD_EXIT ); menu.setCommandListener(this); this.mainMenu = menu;
}
//#style htmlBrowserForm this.browserScreen = new Form("Wikipedia"); //#style htmlBrowser this.htmlBrowser = new HtmlBrowser(); this.browserScreen.append( this.htmlBrowser ); this.browserScreen.addCommand(CMD_BACK); this.browserScreen.addCommand(CMD_MAIN_MENU); this.browserScreen.setCommandListener( new ThreadedCommandListener(this) ); return menu;
Step 2: Design ●
Define Design in polish.css backgrounds { mainBackground { type: horizontal-stripes; first-top-color: #ffff66; first-bottom-color: #008000; second-top-color: #ffffff; second-bottom-color: #33ff00; } }
.screenMain { layout: horizontal-center | vertical-center; margin: 0; padding: 10; padding-vertical: 5; background: mainBackground; }
title { layout: horizontal-center | horizontal-expand; font { face: proportional; size: large; style: bold; color: #000000; } //#if polish.midp2 && polish.hasFloatingPoint text-effect: alien-glow; //#endif background-color: #ffffff;
}
Step 3: Build Application ●
Control Build Process in build.xml / Ant
Step 3: Run Application ●
From within the IDE or the command line ant emulator
Step 4: Deploy Application ●
●
Add mea lifecycle manager to build.xml: [....]
Build application and upload it on ota.j2mepolish.org
Contact
Synyx GmbH & Co. KG Karlstraße 68 76137 Karlsruhe Germany Phone: +49 - 721 - 66 24 866 Fax: +49 - 721 - 66 48 877 To Download the Wikipedia Application point your mobile browser to http://m.j2mepolish.org
Web: http://www.synyx.de IRC: irc.synyx.de #synyx eMail:
[email protected]
