If you have got the requirement to demonstrate your tool built using Java on client machine (third party computers) by deploying your entire tool, and you are worried if your critical application jar files consisting of Java classes could get decompiled and seen by others, you could use some of the following tools:
- Proguard could be used to obfuscate the class files. ProGuard is a free Java class file shrinker, optimizer, obfuscator, and preverifier. In the process of obfuscation, it renames the remaining classes, fields, and methods using short meaningless names.
- JBCO (Java ByteCode Obfuscator) could transform code to be more complex, esoteric, or otherwise obscure in order to hinder reverse-engineering nad decompilation attacks. JBCO is able to operate on Java class files or source and produces obfuscated class files.