Sorry I'm so late getting back to you,
J1 swamped me :-)
I can try it out late in the week.
I'll keep the list informed of how it goes.
TTFN,
Bill Dudney
MyFaces - http://myfaces.apache.org
Cayenne - http://incubator.apache.org/projects/cayenne.html
On May 18, 2006, at 4:28 PM, Andrus Adamchik wrote:
Bill,
I had an idea of how we can go about it, although I got a little
backed up to try it now. Do you have time to play with it?
IIRC ASM bytecode reader uses callback mechanism to notify the
writer when a certain piece of code (such as method) is parsed. In
a non-transforming case the writer simply outputs everything the
reader gives it. So how about this - when a callback is invoked for
a method that we want to intercept, our transformer writes it into
a method with a different name, at the same time generating a
method with the original name that invokes the interceptor code and
the newly created method. This way we can treat the method body as
a black box, and still wrap it with custom code:
Original:
public void setX(Object x) {
... some code ...
}
Transformer output:
public void setX(Object x) {
beforeSetX();
___setX(x);
afterSetX();
}
private void ____setX(Object x) {
... some code ...
}
Andrus
On May 17, 2006, at 10:43 AM, Andrus Adamchik wrote:
Hi Bill,
I will be working on the B3 release today. Once this is done, I'll
take a look at how we can do it with ASM.
Andrus
On May 16, 2006, at 11:40 PM, Bill Dudney wrote:
Hey Andrus,
I spent the bulk of my time investigating ASM route and I don't
see a straightforward way to do the injection. Creating new
methods is straightforward but injecting method calls around the
original method is not so straightforward.
Any ideas how that might work?
Thanks,
-bd-
On May 16, 2006, at 10:22 AM, Andrus Adamchik wrote:
Bill,
This confirms my suspicion that CGlib was not designed for such
use. Probably we may need to try using ASM directly. But of
course if anyone can get in touch with CGlib folks, it would be
nice to doublecheck with them.
Andrus
On May 16, 2006, at 1:50 AM, Bill Dudney wrote:
Hi Andrus,
Sorry I'm still not done.
I've been searching and hacking for way to long now to try to
get this code in. The basic problem is that like you I could
not find a way to wrap the original implementation of the
method using the CGLib implementation path that exists in the
rest of the code. It appears to be easy with the Enhancer API.
I prefer your approach to the Enhancer but I'm at a loss as to
how to make it work. I'll try to get some more time tomorrow to
look at it but I'm going to be very busy doing J1 stuff.
Does anyone know if the CGLib folks are on IRC anywhere?
TTFN,
-bd-
On May 4, 2006, at 7:15 PM, Andrus Adamchik wrote:
I need some help with CGLib. It is great for proxies, but our
enhancer changes the actual class instead of making a proxied
subclass. Such scenario is a pain... Maybe Jeff or someone
else has an idea how to implement the enhancing code below?
Basically I am trying to inject code calling a static delegate
method in three places:
1. Property getter start: DataObjectDelegate.beforeGetProperty
2. Property setter start: DataObjectDelegate.beforeSetProperty
3. Property setter end: DataObjectDelegate.afterSetProperty
I was able to implement a simpler case of creating synthetic
properties with getters and setters (InterfaceMethodInjector),
but got stuck with this one (see TODO's on the
DataObjectAccessorInjector). I suspect we'll have to use ASM
for that, but if anyone can figure a CGlib solution, please
let me know.
Andrus
