J2ME Development on OSX

This follows the tutorial on java.net, which shows how to compile and package J2ME apps manually via the command-line.

First, a wireless toolkit (J2ME SDK) is needed. The mpowerplayer toolkit supports OSX and it comes with a preverifier. The MicroEmulator toolkit has a better emulator than mpowerplayer though.

Once a source file is provided, it is compiled by:
javac -bootclasspath /path/cldc-1.1.jar:/path/midp-2.0.jar /package/path/Source.java

The bootclasspath option uses the specified library files for the compilation, instead of the normal Java environment.

The next step is to preverify the class:
mpowerplayer-folder/osx/preverify/preverify -classpath /path/cldc-1.1.jar:/path/midp-2.0.jar package.name.Source

The preverifier default is to create a folder called output with the same package structure in the current directory. The preverified file is placed there.

In the output folder, create a Manifest.mf with the following:

MIDlet-Name: Source
MIDlet-Version: 1.0.0
MIDlet-Vendor: NameMe


Also in the output folder, create a jar file:

jar cvfm Source.jar Manifest.mf ./com


The penultimate step is to create a jad file descriptor, Source.jad, with the following:

MIDlet-1: Source, , package.name.Source
MIDlet-Name: Source
MIDlet-Version: 1.0.0
MIDlet-Vendor: NameMe
MIDlet-Jar-URL: Source.jar
MIDlet-Jar-Size:
MicroEdition-Profile: MIDP-2.0
MicroEdition-Configuration: CLDC-1.1


The last step is to fill in MIDlet-Jar-Size with the actual number of bytes the jar file takes up. This completes compiling and packaging.

Testing the packaged app in an emulator:
java -jar microemulator-folder/microemulator.jar Source.jad

Allowing the default behaviour of downloading the jad file, which then installs the jar file, set the MIDlet-Jar-URL to:
http://domain/url/Source.jar

Sites of Interest:

J2ME Development on OS X

J2ME Development on OS X, revisited