Introduction to J2ME

1. J2ME

2. Who am I? Lim Chanmann Software Developer Email: chanmannlim@gmail.com Skype: lchanmann Twitter: lchanmann Blog: http://chanmannlim.wordpress.com

3. What is J2ME? Java 2 Micro Edition Is designed to operate in limited resource device (eg. PDAs, mobile, pager)

4. Why? Cross-platform Wide-range support device Easy to start

5. Java Universe

6. J2ME Universe Smaller Larger Pager Mobile PDAs Car Navigation Systems Internet appliance Set-top Box

7. J2ME Basic Configuration: for specifies kind of device Specifies Java Virtual Machine Subset of J2SE Additional APIs Profile: more specific than configuration Based on configuration Add APIs for user interface, persistent storage ,.etc Optional APIs: additional functionality (Bluetooth, Messaging, Media, 3D ,.etc)

8. Specification CLDC: mobile, pager, PDA 160 – 512 kb memory Kilobyte Virtual Machine CLDC 1.0/CLDC 1.1 MIDP 2.0: mobile & pager Min 128 kb RAM (Heap) 8kb for persistent storage Input capacity, network connection

9. J2ME APIs in CLDC 1.1 + MIDP 2.0 MIDP 2.0 javax.microedition.lcdui javax.microedition.lcdui.game javax.microedition.media javax.microedition.media.control javax.microedition.midlet javax.microedition.pki javax.microedition.rms CLDC 1.1 java.lang java.lang.ref java.io java.util java.microedition.io

10. Examples

11. MIDlet & Life clycle MIDP application Life cycle: AMS (Application Management System) destroyApp() Paused pauseApp() startApp() Active Destroyed destroyApp()

12. MIDlet Suite Application package .jar MIDlets + classes + Resources + Manifest information (Version of CLDC & MIDP, name, version, vendor) .jad Same information as Manifest Can be used for installation

13. User Interface with MIDP 2.0 Inherit from MIDlet class Set current displayable object to MIDlet display Displayable: Displayable Screen Canvas Alert TextBox List Form

14. Requirements JDK – J2SE: http://java.sun.com/javase/downloads/index.jsp Wireless Toolkit: http://java.sun.com/products/sjwtoolkit/download.html Editor – Eclipse (Pulsar): http://www.eclipse.org/downloads/

15. See in action Configure development environment Building Helloworld Deployment

16. References Application development with J2ME by EnricoRukzio http://www.j2mesalsa.com http://www.java2s.com http://developers.sun.com/mobility/getstart/ http://www.java-samples.com/j2me/ http://today.java.net/pub/a/today/2005/02/09/j2me1.html