Radon is a Java bytecode obfuscator that I conceptualized in my freshman year of high school. I use Radon to experiment with obfuscation and to learn various parts of Java bytecode.
This project is not likely to be production-safe nor bug free. If you would like some pointers to production-safe (more or less) and less buggy Java bytecode obfuscators, I would suggest one of these:
Additionally, here are some other obfuscators for Java that you could check out for fun:
GNU General Public License v3.0 (The cancer license)