Getting a return value or exception from AspectJ?

Question

I am able to get the signature and arguments from advised method calls, but I cannot figure out how to get the return values or exceptions. I'm kind of assuming that it can be done in some way using around and proceed.

Answer 1

You can use after() returning and after() throwing advices as in beginning of the following document. If you're using @AspectJ syntax please refer to @AfterReturning and @AfterThrowing annotations (you can find samples here).

Answer 2

You can also get return value using after returing advice.

package com.eos.poc.test;   

public class AOPDemo {
            public static void main(String[] args) {
                AOPDemo demo = new AOPDemo();
                String result= demo.append("Eclipse", " aspectJ");
           }
            public String append(String s1, String s2) {
                System.out.println("Executing append method..");
                return s1 + s2;
          }

}

The defined aspect for getting return value:

public aspect DemoAspect {
    pointcut callDemoAspectPointCut():
        call(* com.eos.poc.test.AOPDemo.append(*,*));

    after() returning(Object r) :callDemoAspectPointCut(){
        System.out.println("Return value: "+r.toString()); // getting return value

    }