java在方法返回之前执行钩子代码

Question

I would like to have a post hook that is run before a method return. It should be possible add a hook to any method without modifying existing code. Is there a tool or technology that helps realise this? Is javassist a candidate here? If yes, how to pass parameters to the hook? Ideally whatever the method returns should be passed as parameter to the hook.

Answer 1

Yes, the technique is called byte code engineering. There are several popular tools. The most famous higher level tool is called AspectJ.

However there are lower level tools like CGLIB, Javassiste, BCEL.