ProGuard can be seamlessly integrated in Oracle's Wireless Toolkit (WTK) for Java Micro Edition (JME).

The WTK already comes with a plug-in for ProGuard. Alternatively, ProGuard offers its own plug-in. This latter implementation is recommended, as it more up to date and it solves some problems. It is also somewhat more efficient, invoking the ProGuard engine directly, instead of writing out a configuration file and running ProGuard in a separate virtual machine.

In order to integrate this plug-in in the toolkit, you'll have to put the following lines in the file {j2mewtk.dir}/wtklib/Linux/ktools.properties or {j2mewtk.dir}\wtklib\Windows\ktools.properties (whichever is applicable).

obfuscator.runner.class.name: proguard.wtk.ProGuardObfuscator
obfuscator.runner.classpath: /usr/local/java/proguard/lib/proguard.jar

Please make sure the class path is set correctly for your system.

Once ProGuard has been set up, you can apply it to your projects as part of the build process. The build process is started from the WTK menu bar:

Project → Package → Create Obfuscated Package

This option will compile, shrink, obfuscate, verify, and install your midlets for testing.

Should you ever need to customize your ProGuard configuration for the JME WTK, you can adapt the configuration file proguard/wtk/default.pro that's inside the proguard.jar.