null returned

[oberon777]

I am using invocation.invokeNext() for caller invocations to capture the return result of the method being intercepted. However, it appears that that value is null.

The pointcut in question is

 <bind pointcut="call(* java.lang.Class->newInstance(..))">
 <interceptor class="CallerInterceptor"/>
 </bind>

I don't think exceptions are being thrown. Any thoughts?

[kabirkhan]

I am sure we have tests in our testsuite for this. In any case I gave it a go, and it worked for me.

public class ConstructorInterceptor implements Interceptor
{
 public String getName() { return "ConstructorInterceptor"; }

 public Object invoke(Invocation invocation) throws Throwable
 {
 try
 {
 System.out.println("<<< Doing it");
 Object o = invocation.invokeNext();
 System.out.println("Got o " + (o != null));
 return o;
 }
 finally
 {
 System.out.println(">>> Leaving ConstructorInterceptor");
 }
 }
}

<aop>

 <bind pointcut="call(* java.lang.Class->newInstance(..))">
 <interceptor class="ConstructorInterceptor"/>
 </bind>

</aop>

public class Driver
{
 public static void main(String[] args) throws Exception
 {
 Class clazz = POJO.class;
 System.out.println("--- new POJO(); ---");
 POJO pojo = (POJO)clazz.newInstance();
 System.out.println("Got pojo " + (pojo != null));
 }
}

<?xml version="1.0" encoding="UTF-8"?>
<aop>

 <bind pointcut="call(* java.lang.Class->newInstance(..))">
 <interceptor class="ConstructorInterceptor"/>
 </bind>

</aop>

Output:

 [java] --- new POJO(); ---
 [java] <<< Doing it
 [java] empty constructor
 [java] Got o true
 [java] >>> Leaving ConstructorInterceptor
 [java] Got pojo true

[oberon777]

Hmm.. thanks for such a detailed reply. I'll experiment some more to see what was causing this issue.