Nothing. No obfuscation either really. Heavy obfuscation could hurt performance, and light obfuscation can break reflection that might be used by plugins.
There isn't much value in trying to protect their source code. IDEs are evolving rapidly in response to languages, any decompilation you prepare would be outdated immediately. And nearly all JVM programs can be trivially cracked anyways, even if heavily obfuscated/guarded.
There isn't much value in trying to protect their source code. IDEs are evolving rapidly in response to languages, any decompilation you prepare would be outdated immediately. And nearly all JVM programs can be trivially cracked anyways, even if heavily obfuscated/guarded.