There are two packaging options - Create Obfuscated Package and Create Package.
When the Create Package action is run, it will deploy the JAD file and JAR file into the deployment directory specified in the Preferences. The deployed JAR file will contain the verified classes and resources.
When the Create Obfuscated Package action is run, it will deploy the JAD file and JAR file into the deployment directory specified in the Preferences. The deployed JAR file will be obfuscated by the using the Proguard Java Tool as specified in the Preferences.
Obfuscated packages are useful in providing a small level of security for your deployed MIDlets. More importantly, obfuscation generally leads to smaller deployed JAR file sizes.
In order to produce obfuscated packages, the Proguard Java obfuscation tools must be installed and the root of the Proguard installation must be configured in the Obfuscation Preferences. Proguard is a free open-source library that is available for download from http://proguard.sourceforge.net/.
It is possible that there will be warnings or errors during the obfuscation process. When this occurs, a prompt will be opened to allow packaging to continue or be cancelled.
If the warning or error can be safely ignored, you may select Continue and MTJ will attempt to continue creating the obfuscated package. Depending on the type and severity of the problems encountered the package may not be able to be created.