How can I intercept execution of all the methods in a Java application using Groovy?

Question

Is it possible to intercept all the methods called in a application? I'd like to do something with them, and then let them execute. I tried to override this behaviour in Object.metaClass.invokeMethod, but it doesn't seem to work.

Is this doable?

Answer 1

Have you looked at Groovy AOP? There's very little documentation, but it allows you to define pointcuts and advice in a conceptually similar way as for AspectJ. Have a look at the unit tests for some more examples

The example below will match all calls to all woven types and apply the advice before proceeding:

// aspect MyAspect
class MyAspect {
  static aspect = {
    //match all calls to all calls to all types in all packages
    def pc = pcall("*.*.*")

    //apply around advice to the matched calls
    around(pc) { ctx ->
      println ctx.args[0]
      println ctx.args.length
      return proceed(ctx.args)
    }
  }
}
// class T
class T {
  def test() {
    println "hello"
  }
}
// Script starts here
weave MyAspect.class
new T().test()
unweave MyAspect.class