Re: [aspectj-users] Serialization aspect problem

["Bhaskar Maddala" <maddalab@xxxxxxxxx>]

>> I think there must be a simpler way to do this where I don't have to access
the attributes and copy them one by one...  In the OO example I was messing
around with I didn't have to make new references or copy attributes.

Why did'nt you say so.... (just do not call proceed)


Object around() : call(Foo.new(..)) && !within(SerializationAspect)
   {
       try  {
           Foo f1 = (Foo) SerializeObject.load(filename);
           return f1;
       }
       catch(Exception e)  {
           System.out.println("File not found "+ e);
           return new Foo();
       }
   }

On Dec 19, 2007 2:11 PM, neil loughran <loughran@xxxxxxxxxxxxxxxx> wrote:
> Thanks for that Dean,
>
> I suspected as much…
>
> I'll give it a go…
>
> Cheers
> Neil
>
> ________________________________________
> From: aspectj-users-bounces@xxxxxxxxxxx
> [mailto:aspectj-users-bounces@xxxxxxxxxxx] On Behalf Of Dean Wampler
> Sent: 19 December 2007 19:05
>
> To: aspectj-users@xxxxxxxxxxx
> Subject: Re: [aspectj-users] Serialization aspect problem
>
> I'm not positive, but I suspect you need to use around advice, instead of
> after advice. Make sure it returns the newly constructed object.
>
> dean
>
> On Dec 19, 2007, at 1:01 PM, neil loughran wrote:
>
>
> Thanks Bhaskar,
>
> I think there must be a simpler way to do this where I don't have to access
> the attributes and copy them one by one... In the OO example I was messing
> around with I didn't have to make new references or copy attributes.
>
> So I think it may have something to do with the joinpoint/advice type?
>
> Cheers
> Neil
>
>
>
> -----Original Message-----
> From: aspectj-users-bounces@xxxxxxxxxxx [mailto:aspectj-users-
> bounces@xxxxxxxxxxx] On Behalf Of Bhaskar Maddala
> Sent: 19 December 2007 18:33
> To: aspectj-users@xxxxxxxxxxx
> Subject: Re: [aspectj-users] Serialization aspect problem
>
> A modified aspect that works
>
> public aspect SerializationAspect
> {
> declare parents: Foo implements Serializable;
> String filename = "Foo.ser";
>
> // problematic advice? - no longer problematic
> after(Foo f): this(f) && execution(Foo.new()) {
> try {
> Foo f1 = (Foo) SerializeObject.load(filename);
> System.out.println("[MyAspect] x = "+f1.getX()); // works fine
> here!
> f.setX(f1.getX()); // it's all about the references.....
> }
>
> catch(Exception e) {
> System.out.println("File not found "+ e);
> }
> }
>
> after(Foo f): this(f) && execution(public void Foo.setX(String)) &&
> !within(SerializationAspect) {
> System.out.println("Setting");
> try {
> SerializeObject.save(f,filename);
> }
>
> catch(IOException e) {
> System.out.println("File not found "+ e);
> }
> }
> }
>
> Thanks
> Bhaskar
>
> On Dec 19, 2007 10:59 AM, neil loughran <loughran@xxxxxxxxxxxxxxxx> wrote:
> Hi all
>
> I'm trying to figure out what exactly is wrong with my pointcut/advice
> for a
> serialisation aspect.
>
> The code below is fairly simple but captures the problem I have.
> Basically
> I create an object of type Foo and set Foo.x to Foobar. My aspect has
> two
> advice.. one for capturing instantiation of Foo and the other for
> capturing
> setX on Foo objects.
>
> On instantiation of Foo, I attempt to load a serialised file (Foo.ser).
> If
> it doesn't exist then an exception is thrown but the program carries on
> as
> usual. When I setX the second advice serializes the Foo object as file
> Foo.ser.
>
> Therefore when I run the program a second time I expect the Foo.ser file
> to
> load and the contents loaded to the Foo object. However, for some
> reason I
> can't seem to show the loaded value in FooDriver only in the aspect.
> Therefore, I am assuming my first advice is incorrectly written and the
> loaded content is lost outside of the aspect. I have tried a few
> different
> varieties of around/after returning advice to no avail.
>
> Can anyone spot the mistake in the first advice... it's driving me nuts!
>
> Many thanks
> Neil Loughran
>
>
>
> import java.io.*;
>
> class FooDriver {
> public static void main(String args[]) {
> Foo f = new Foo();
> System.out.println("[FooDriver] x = "+f.getX()); // always
> null!!?
>
> f.setX("Foobar");
> }
> }
>
> class Foo {
> public String x;
> public void setX(String _x) {
> x = _x;
> }
>
> public String getX() {
> return x;
> }
> }
>
> aspect MyAspect {
> declare parents: Foo implements Serializable;
> String filename = "Foo.ser";
>
> // problematic advice?
> after(Foo f): this(f) && execution (Foo.new()) {
> try {
> f = (Foo) SerializeObject.load(filename);
> System.out.println("[MyAspect] x = "+f.getX()); // works
> fine
> here!
> }
>
> catch(Exception e) {
> System.out.println("File not found "+ e);
> }
> }
>
> after(Foo f): this(f) && execution(public void Foo.setX(String)) {
> System.out.println("Setting");
> try {
> SerializeObject.save(f,filename);
> }
>
> catch(IOException e) {
> System.out.println("File not found "+ e);
> }
> }
> }
>
> class SerializeObject {
> public static void save(Object obj, String filename) throws
> IOException
> {
> System.out.println("Saving file: "+filename);
> ObjectOutputStream objstream = new ObjectOutputStream(new
> FileOutputStream(filename));
> objstream.writeObject(obj);
> objstream.close();
> }
>
> public static Object load(String filename) throws Exception {
> System.out.println("Loading file: "+filename);
> ObjectInputStream objstream = new ObjectInputStream(new
> FileInputStream(filename));
> Object obj = objstream.readObject();
> objstream.close();
> return obj;
> }
> }
>
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> _______________________________________________
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>
> _______________________________________________
> aspectj-users mailing list
> aspectj-users@xxxxxxxxxxx
> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>
> Dean Wampler, Ph.D.
> dean at objectmentor.com
> http://www.objectmentor.com
> See also:
> http://www.aspectprogramming.com AOP advocacy site
> http://aquarium.rubyforge.org AOP for Ruby
> http://www.contract4j.org Design by Contract for Java5
>
>
>
>
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>