The jarg reduces the size of a jar file in which java class files are stored. "Size curtailment can be carried out simply" is the 1st target. However, as a result of processing by jarg, since a Java class file is optimized, it becomes quicker, and since it is renamed, it becomes that it is harder to be analyzed. That is, jarg is 'Java Optimizer', and it is 'Java Obfuscator' and is also 'Java Shrinker' or 'Java Reducer'.
Finally, jarg is 100% Pure Java, and an open source, and you can use it for free.URL: http://jarg.sourceforge.net/
Licence: BSD License