J2ME Programming

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J2ME Programming
By Hiroyuki Akimoto
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Contents

• J2ME and its Technologies
• i-appli Programming

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Mobile Java

• We can run the Java program in our mobile device
  (such as mobile phone, PDA).

http//www.nokia.com/phones/9210/demo/intro_and_gu
ide.html
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about J2ME

• Java2 is divided in three platform
• J2EE (Java2 Platform Enterprise Edition)
• Business applications.
• J2SE (Java2 Platform Standard Edition)
• General applications (In this lecture, using this
  platform).
• J2ME (Java2 Platform Micro Edition)
• Small devices such as mobile phone, PDA, car
  navigation.

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about J2ME

• J2ME Platform needs configuration and profile.

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CLDC (Connected Limited Device Configuration)

• Mobile Phone Java use this configuration
• Deleted features
• Floating Point
• Finalize
• Thread Group
• Java Native Interface (JNI)
• Reflection
• Weak References

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Profiles for mobile phone
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DoJa and MIDP

• Differences between DoJa and MIDP

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Detail of i-appli

• DoCoMo 503, 504, FOMA
• Limited capacity
• 503i 10Kbyte
• 504i 30Kbyte
• FOMA 30Kbyte
• Nonvolatile Memory Size
• 503i 10Kbyte
• 504i 100Kbyte
• FOMA 100Kbyte
• Applications can connect to only downloaded server

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How to make i-appli

• API
• JavaTM 2 SDK, Standard Edition Version 1.3.0 or
  later
• CLDC
• Emulator
• J2ME Wireless SDK for the DoJa
• i-jade popular emulator to run i-appli

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How to make i-appli

• Flow of development

Write i-appli Program
Compile
Preverify
gtjavac filename
gtpreverify classfile
Play i-appli with Your ke-tai!!
Make jar archive
Write jam and html
gtjar cfm classfile
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Form of i-appli program

• Need to extend IApplication class.

import com.nttdocomo.ui. public class
ClassName extends IApplication // Called
when this application is started public void
start() // Called when this application is
resumed public void resume()
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Hello World (Source Code)
import com.nttdocomo.ui. public class
HelloWorld extends IApplication public void
start() HelloCanvas canvas new
HelloCanvas() Display.setCurrent(canvas)
public void resume() class HelloCanvas
extends Canvas public void paint(Graphics
g) g.drawString("Hello world",0,20)

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Hello World (Compile)

• Compile
• javac bootclasspath CLDCAPI classpath DoJaAPI
  HelloWorld.java
• Run (in emulator i-jade)
• java jar i-jade.jar
• Preverify
• preverify classpath CLDCAPIDoJaAPI d .
  HelloWorld
• Make jar archive
• jar cfM HelloWorld.jar HelloWorld.class
  HelloCanvas.class

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HelloWorld (Make jam file)

• Sample jam file

AppName My First i-appli PackageURL
HelloWorld.jar AppSize 235 AppClass
HelloWorld LastModified Sun, 9 Jun 2002 164554
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HelloWorld (Make html file)

• Sample html file

lthtmlgt ltOBJECT declare idiappli
dataHelloWorld.jam typeapplication/x-jamgt lt/
OBJECTgt ltA ijamiappli hrefindex.htmgtMy
First i-applilt/Agt lt/htmlgt
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HelloWorld (Download)

• If you have DoCoMos 503i or 504i phone, you can
  visit this url and download this application.

lthtmlgt ltOBJECT declare idiappli
dataHelloWorld.jam typeapplication/x-jamgt lt/
OBJECTgt ltA ijamiappli hrefindex.htmgtMy
First i-applilt/Agt lt/htmlgt
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References

• J2ME Technologies (English)
• http//java.sun.com/j2me/
• Java Technologies for WIRELESS (Japanese)
• http//jdc.sun.co.jp/wireless/
• i-appli Specification (Japanese)
• http//www.nttdocomo.co.jp/p_s/imode/java/index.ht
  ml
• i-jade (Japanese)
• http//www.zentek.com/i-JADE/ja/
• Tutorial to make i-appli (Japanese)
• http//www.kajas.com/tutorial/index.html
• Amateur creaters i-appli search site (Japanese)
• http//www.kajas.com/