Midlet

Mobile Computing MIDP

Midlets are the java classes used (similar to applets) to establish java code executing on small mobile devices, such as mobile phones.
Search for information on CLDC, MIDP, J2ME to get information about this or check the J2ME Device List.

Sun's J2ME class library set is a reduced set from the J2SE and holds additional javax classes for the small devices. Suns's Java sites have plenty to start with http://java.sun.com/j2me .

I recommend using IMB DeviceDeveloper as IDE for developing (know as WSDD) This is based on the eclipse platform as other IBM products.

Since Nov04 I have switched to using the skd provided from Nokia supporting eclipse 2.1 and 3.0 and other IDEs, but my favourite is still eclipse and integration was pretty easy.

For Eclipse 3.1/3,2 plugins for Sun's WTK and other SDKs such as Nokias are offered. There is also support for obfuscating (which I was missing, since size does matter). So see EclipseME and ProGuard. For building the final midelt, I tried antenna, but also had to face some issues (see eclipseME and Antenna).

Development using MacOS is supported by mpowerplayer and the WTK2.2. The WTK2.2 actually does not ship for MacOS, but I used the preverifier from mpowerplayer to get my build file working. During development time, it is recommended to use the MicroEmulator. See MicroEmulator for MacOS j2me development.

Midlets featured here

• WorkingTime - Register Working hours to control time account
• ShoppingList - Simple Shopping List (or ToDo List)
• MobileControl - Basic suite to remote control pc applications via bluetooth mobile
• 5ud0ku - A Sudoku Game with Generator and Solver
• just1 - A Hitori Game
• k4kur0 - A Kakuro Game with Generator and Solver

Issues with J2ME development

Issues J2ME

Midlets using Fullscreen

Since MIDP 2.0 midlets supports the fullscreen mode. There is also a specific Nokia fullscreen implementation. Check out FullscreenCanvasExample to see how to build a midlet which supports fullscreen mode with just one single JAR which will run on MIDP 1.0 and MIDP 2.0 devices.

More Free midlets

You will find some free midlets at http://midlet.org/index2.jsp

Information about mobile device performance

http://www.club-java.com/TastePhone/J2ME/MIDP_Benchmark.jsp

Information about known issues

http://www.j2mepolish.org/devices/issues.html