[aspectj-users] Using AspectJ and mock objects

["SADER, KEITH D (Contractor)" <KEITH.D.SADER@xxxxxxxx>]

Hi, I'm trying to use aspects to mock 'on the fly' a domain layer class.  I've tried to follow Nicholas Leseicki's great article at http://www-106.ibm.com/developmerworks/java/library/j-aspect2.  I've had some luck, but I'm getting  some unexpected behavior.

My aspect looks like this - real names replaced to protect the innocent.

import java.util.Collection;
// import other stuff

public aspect DAOAspect
{
    pointcut inTest() : execution(public void MyTestCase.*());
    pointcut findThings(String searchStr) :
        cflow(inTest()) &&
        call(Collection MyDAO.find*(*)) && // MyDAO is a concrete class, not an interface.
        !call(Collection MockMyDAO.find*(*)) &&
        args(searchStr);

    Collection around(String searchStr) : findThings(searchStr)
    {
        System.out.println("In the aspect");
        System.out.println("searchStr is : " + searchStr);
        return new MockMyDAO().findStuff(searchStr);
    }
}

First bit of unexpected behavior: 
I see that my aspect is called twice via the System.out.println()s
"In the aspect"
"search"
"In the aspect"
"search"
...

Why would this happen?  I believe I'm only calling into the mocked DAO once.
// test case
public void testFind()
{
    assertTrue(0 < daoCollaborator.find("search"));
}

// code under test in DAOCollaborator
public Collection find(String searchStr)
{
    return new MyDAO().findStuff(searchStr);
}

// MyMockDAO over-ride
public Collection findStuff(String searchStr)
{
   return mockStuff;
}

Second question/behavior.
Is it possible for me to just return the MockDAO whenever the DAO is invoked/used?  It would make it easier for me to just return the mock object reference instead of having the aspect return method level items.  I'm not clear on the syntax/advice I need to  use to do this.

thanks,
---
Keith Sader
Nash Resources Group sub-contracting for Computer Sciences Corporation
IAD:TFAS
Email:keith.d.sader@xxxxxxxx
We've got a blind date with destiny, and it looks like she ordered the lobster.