(no subject)

[Ravi Chandra-3]

hi,

I am trying hard to get a solution to this problem since last 4 days.. but no luck; the issue is as below:

I have java classes of this form

public class UserAttributes implements Interceptable {
    private List<String>        alias;
   
    private void someMethod(){
           alias = new ArrayList(); // point 1
           .... etc etc
    }
}

Now the problem is :

When ever a variable is assigned to new ArrayList() i want it to be changed to new MyArrayList() instead

i.e..: the point 1 above changes to an eqvivalent of

alias = new MYArrayList();

I am able to get this done

aspect abc {
    pointcut listCut(Interceptable m, IN in):target(m) && set(java.util.List+ *);
    after(Interceptable m, IN in):listCut(m,in){
          UserAttributes.setAlias( new MyArrayList());
    }
}

but the point cut is getting very class specific. I have abt 1000 classes which have to be modified this way where ever the ArrayList is being used, now with this approach i need to write 1000 files; isnt there a generic way to do this?

Any pointers/ help ? please suggest.

regards,
ravi


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[Simone Gianni-2]

Hi Ravi,
you can declare a pointcut around the creation of any ArrayList,
returning MyArrayList as long as they are assign-compatible.

That means that as long as :

public class MyArrayList extends ArrayList { ...

you can write :

ArrayList around() : call(* ArrayList.new()) {
  return new MyArrayList();
}

This will replace do the trick. You can narrow it down to some classes
using within, withincode etc..

ArrayList around() : call(* ArrayList.new()) && within(com.mycompany.*) {
   return new MyArrayList();
}

And you can add other advice to add parameters  :

ArrayList around(int size) : call(* ArrayList.new(int)) && args(size) {
   return new MyArrayList(size);
}

etc...

In my Apache Magma Lab I use this kind of advice extensively to offer a
simpler alternative to the factory pattern/dependency injection/context
pollution.

Hope this helps,
Simone





Ravi Chandra wrote:

> hi,
>
> I am trying hard to get a solution to this problem since last 4 days..
> but no luck; the issue is as below:
>
> I have java classes of this form
>
> public class UserAttributes implements Interceptable {
>     private List<String>        alias;
>    
>     private void someMethod(){
>            *alias = new ArrayList(); // point 1*
>            .... etc etc
>     }
> }
>
> Now the problem is :
>
> When ever a variable is assigned to new ArrayList() i want it to be
> changed to new MyArrayList() instead
>
> i.e..: the point 1 above changes to an eqvivalent of
>
> *alias = new MYArrayList();*
>
> I am able to get this done
>
> aspect abc {
>     pointcut listCut(Interceptable m, IN in):target(m) &&
> set(java.util.List+ *);
>     after(Interceptable m, IN in):listCut(m,in){
>           *UserAttributes.setAlias( new MyArrayList());*
>     }
> }
>
> *but the point cut is getting very class specific. *I have abt 1000
> classes which have to be modified this way where ever the ArrayList is
> being used, now with this approach i need to write 1000 files; isnt
> there a generic way to do this?
>
> Any pointers/ help ? please suggest.
>
> regards,
> ravi
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> aspectj-users mailing list
> aspectj-users@...
> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>  

--
Simone Gianni            CEO Semeru s.r.l.           Apache Committer
http://www.simonegianni.it/

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[Ravi Chandra-3]

hi,

That was an intelligent soln.

But, I have annotations on each of the fields( i didnt mention this previously) and during the interception by AOP i would like to access the annotated info also.

Original Class:
public class UserAttributes implements Interceptable {
    @IN(3)
    private List<String> alias;
 
   public int getAge() {
        return age;
    }

    public static void main(String[] argv) {
        UserAttributes u = new UserAttributes();
        u.alias = new ArrayList();
        u.children = new HashMap<String, String>();
    }
}

and i tried:

    pointcut annCut(Interceptable m, IN in):target(m) && set(@IN* (*) * ) && @annotation(in);

    pointcut annListCut(Interceptable m, IN in) : cflow(annCut(m,in)) && cflow(listCut()) && target(Interceptable+);

    after/ Around (Interceptable m, IN in): annListCut(m,in){
        //here i should be able to get the fields annotation + return MYList object
        System.out.println("point cut + annotation is.." + in.value());
    }

But this is cutting off

    public int getAge() {
        return age;
    }

method also, which is not intended.

Any ideas please..

regards,
ravi

On Sun, Jun 21, 2009 at 3:40 PM, Simone Gianni <simoneg@...> wrote:

Hi Ravi,
you can declare a pointcut around the creation of any ArrayList, returning MyArrayList as long as they are assign-compatible.

That means that as long as :

public class MyArrayList extends ArrayList { ...

you can write :

ArrayList around() : call(* ArrayList.new()) {
 return new MyArrayList();
}

This will replace do the trick. You can narrow it down to some classes using within, withincode etc..

ArrayList around() : call(* ArrayList.new()) && within(com.mycompany.*) {
 return new MyArrayList();
}

And you can add other advice to add parameters  :

ArrayList around(int size) : call(* ArrayList.new(int)) && args(size) {
 return new MyArrayList(size);
}

etc...

In my Apache Magma Lab I use this kind of advice extensively to offer a simpler alternative to the factory pattern/dependency injection/context pollution.

Hope this helps,
Simone





Ravi Chandra wrote:

hi,

I am trying hard to get a solution to this problem since last 4 days.. but no luck; the issue is as below:

I have java classes of this form

public class UserAttributes implements Interceptable {
   private List<String>        alias;
     private void someMethod(){
          *alias = new ArrayList(); // point 1*
          .... etc etc
   }
}

Now the problem is :

When ever a variable is assigned to new ArrayList() i want it to be changed to new MyArrayList() instead

i.e..: the point 1 above changes to an eqvivalent of

*alias = new MYArrayList();*

I am able to get this done

aspect abc {
   pointcut listCut(Interceptable m, IN in):target(m) && set(java.util.List+ *);
   after(Interceptable m, IN in):listCut(m,in){
         *UserAttributes.setAlias( new MyArrayList());*
   }
}

*but the point cut is getting very class specific. *I have abt 1000 classes which have to be modified this way where ever the ArrayList is being used, now with this approach i need to write 1000 files; isnt there a generic way to do this?

Any pointers/ help ? please suggest.

regards,
ravi

------------------------------------------------------------------------

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aspectj-users@...
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--
Simone Gianni            CEO Semeru s.r.l.           Apache Committer
http://www.simonegianni.it/

_______________________________________________
aspectj-users mailing list
aspectj-users@...
https://dev.eclipse.org/mailman/listinfo/aspectj-users

_______________________________________________
aspectj-users mailing list
aspectj-users@...
https://dev.eclipse.org/mailman/listinfo/aspectj-users