[
Date Prev][
Date Next][
Thread Prev][
Thread Next][
Date Index][
Thread Index]
[
List Home]
|
Re: [aspectj-users] staticinitialization and target class
|
no error - so did your advice actually apply? Were there any markers
in eclipse or weavinfo messages (if you built on the command line, Ant
or load time weaving)?
I suggested registering by name so you could drive the load of the
class outside of the bean in your registration handling mechanism.
Andy
On 28 April 2010 10:44, Mohammad Norouzi <mnrz57@xxxxxxxxx> wrote:
> No Andy there is no error, actually the list of registered classes are
> empty... it means no class has been registered itself. I need its Class
> object because I want to read the @Observer(events = "SOME_EVENT") so I can
> extract which events is binded to which classes (Session bean) and then I
> can look them up when an event has been fired
>
> On 4/28/10, Andy Clement <andrew.clement@xxxxxxxxx> wrote:
>>
>> Although AspectJ tries to create code that decompiles cleanly, there
>> are some situations where it does not. The code is fine (otherwise
>> you'd get a verifyerror), it is just the decompiler that cannot cope -
>> I don't use them, I just read the bytecode :) Decompilers usually
>> match on patterns and if you stray from a common pattern produced by
>> javac, the decompiler will not understand.
>>
>> You still didn't mention how it fails.... do you get an error or is
>> it just not running the advice?
>>
>> You could register the type by name rather than class reference if
>> that makes any difference...
>>
>>
>> Andy
>>
>>
>> On 28 April 2010 10:14, Mohammad Norouzi <mnrz57@xxxxxxxxx> wrote:
>> > Thank you Simone and Andy
>> > Both pointcut and advice are exactly the same you suggested, at first I
>> > thought there is a problem in advice which makes static block so, and
>> > yes I
>> > am using JD to decompile the code and as you found perhaps that
>> > //ERROR// is
>> > decompiler issue, if it is so, then my static block doesn't work...
>> >
>> > Well... As I understand you mean that if I load the class manually say
>> > using
>> > Class.forName() it will be ok however I will give it a try tomorrow but
>> > I
>> > think there are some issues.... first, this class is a EJB session bean
>> > and
>> > since it is a managed object by app server I am not sure if I can load
>> > it
>> > manually second... at deploy time, app server will load it, isn't that
>> > enough?
>> >
>> > thank you for spending your time
>> >
>> > On 4/28/10, Simone Gianni <simoneg@xxxxxxxxxx> wrote:
>> >>
>> >> Hi Mohammad,
>> >> I've found this page : http://java.decompiler.free.fr/?q=node/118 , it
>> >> seems that JD produces the raw bytecode commented when it is not able
>> >> to
>> >> decompile it properly, which means that it is JD giving the error, not
>> >> the
>> >> code itself in error. I haven't been using JD lately, so I can't
>> >> remember
>> >> how to configure it properly, but the bytecode seems correct, so the
>> >> problem
>> >> must be somewhere else.
>> >> Simone
>> >>
>> >> 2010/4/28 Simone Gianni <simoneg@xxxxxxxxxx>
>> >>>
>> >>> Hi Mohammad,
>> >>> mmm ... the decompiled bytecode seems correct : it creates a joinpoint
>> >>> static part, then executes the previous static initializer (which is
>> >>> empty),
>> >>> and then calls the after advice both when an exception is raised and
>> >>> when no
>> >>> exception is raised.
>> >>> Bytecode, AFAIK, cannot be commented out, is that the output of javap,
>> >>> dj
>> >>> or which other tool?
>> >>> Obviously, static initializer is executed only when the class is
>> >>> loaded
>> >>> for the first time in the JVM, if it is not loaded it will not be
>> >>> called and
>> >>> the class not be registered. Java lacks a serious "service discovery"
>> >>> system, cause for backward compatibility with applets classloaders
>> >>> does not
>> >>> have a method for "listing" the classpath, not to mention to list
>> >>> which
>> >>> classes are annotated with a specific annotations. Apt is the tool
>> >>> that can
>> >>> ease this pain, creating a text file from classes annotated with a
>> >>> specific
>> >>> annotation, but unfortunately it works at compile time, not at
>> >>> runtime,
>> >>> that's why there is still the need for files like persistence.xml in
>> >>> JPA and
>> >>> web.xml in jars.
>> >>> To make a long story short, as Andy did in his code, somewhere you
>> >>> must
>> >>> still call "new ClassUnderObservation()" or at least
>> >>> Class.forName("com.foo.ClassUnderObservation") or access a static
>> >>> field or
>> >>> method of that class to get it loaded by the jvm, otherwise no static
>> >>> init,
>> >>> no registration in the aspect.
>> >>> Simone
>> >>>
>> >>> 2010/4/28 Andy Clement <andrew.clement@xxxxxxxxx>
>> >>>>
>> >>>> You didn't mention how it fails?? Here is Simones code in a real
>> >>>> program, appears to work. What is different about your code or that
>> >>>> particular type? Perhaps narrow your pointcut to a specific type to
>> >>>> test the registration logic is working before expanding it to cover
>> >>>> more types?
>> >>>>
>> >>>> === A.aj ===
>> >>>> package com.foo;
>> >>>>
>> >>>> import java.lang.annotation.Retention;
>> >>>> import java.lang.annotation.RetentionPolicy;
>> >>>> import java.util.*;
>> >>>>
>> >>>> import org.aspectj.lang.reflect.InitializerSignature;
>> >>>>
>> >>>> @Retention(RetentionPolicy.RUNTIME)
>> >>>> @interface Observer {}
>> >>>>
>> >>>> aspect A {
>> >>>> public static void main(String[] args) {
>> >>>> new C();new D(); new E();
>> >>>> }
>> >>>>
>> >>>> static List<Class> registry = new ArrayList<Class>();
>> >>>>
>> >>>> pointcut observerKlasses(): staticinitialization(@Observer com..*);
>> >>>>
>> >>>> after(): observerKlasses() {
>> >>>> InitializerSignature initsig =
>> >>>> (InitializerSignature)thisJoinPointStaticPart.getSignature();
>> >>>> Class klass = initsig.getDeclaringType();
>> >>>> registry.add(klass);
>> >>>> System.out.println("Registering "+klass);
>> >>>> }
>> >>>>
>> >>>> }
>> >>>>
>> >>>> @Observer
>> >>>> class C {}
>> >>>>
>> >>>> class D{}
>> >>>>
>> >>>> @Observer
>> >>>> class E {}
>> >>>> ===
>> >>>> ajc A.aj
>> >>>> java A
>> >>>> Registering class com.foo.C
>> >>>> Registering class com.foo.E
>> >>>>
>> >>>> cheers,
>> >>>> Andy
>> >>>>
>> >>>> On 28 April 2010 00:30, Mohammad Norouzi <mnrz57@xxxxxxxxx> wrote:
>> >>>> > Hi Simone,
>> >>>> > Thanks... I did what you said but there is a problem. During the
>> >>>> > compile
>> >>>> > there is no error but it seems the static block doesn't work. I
>> >>>> > tried
>> >>>> > to
>> >>>> > decompile the target class to see what changes AspectJ has applied
>> >>>> > and
>> >>>> > I can
>> >>>> > see a static block has been created but it is commented as follow:
>> >>>> >
>> >>>> >
>> >>>> > // ERROR //
>> >>>> > static
>> >>>> > {
>> >>>> > // Byte code:
>> >>>> > // 0: new 87 org/aspectj/runtime/reflect/Factory
>> >>>> > // 3: dup
>> >>>> > // 4: ldc 88
>> >>>> > // 6: ldc 90
>> >>>> > // 8: invokestatic 96 java/lang/Class:forName
>> >>>> > (Ljava/lang/String;)Ljava/lang/Class;
>> >>>> > // 11: invokespecial 99
>> >>>> > org/aspectj/runtime/reflect/Factory:<init>
>> >>>> > (Ljava/lang/String;Ljava/lang/Class;)V
>> >>>> > // 14: astore_0
>> >>>> > // 15: aload_0
>> >>>> > // 16: ldc 101
>> >>>> > // 18: aload_0
>> >>>> > // 19: ldc 103
>> >>>> > // 21: ldc 90
>> >>>> > // 23: invokevirtual 107
>> >>>> > org/aspectj/runtime/reflect/Factory:makeInitializerSig
>> >>>> >
>> >>>> >
>> >>>> > (Ljava/lang/String;Ljava/lang/String;)Lorg/aspectj/lang/reflect/InitializerSignature;
>> >>>> > // 26: iconst_0
>> >>>> > // 27: invokevirtual 111
>> >>>> > org/aspectj/runtime/reflect/Factory:makeSJP
>> >>>> >
>> >>>> >
>> >>>> > (Ljava/lang/String;Lorg/aspectj/lang/Signature;I)Lorg/aspectj/lang/JoinPoint$StaticPart;
>> >>>> > // 30: putstatic 79 com/foo/listener/MyListener1:ajc$tjp_0
>> >>>> > Lorg/aspectj/lang/JoinPoint$StaticPart;
>> >>>> > // 33: goto +28 -> 61
>> >>>> > // 36: astore_0
>> >>>> > // 37: aload_0
>> >>>> > // 38: instanceof 71
>> >>>> > // 41: ifeq +8 -> 49
>> >>>> > // 44: aload_0
>> >>>> > // 45: checkcast 71 java/lang/ExceptionInInitializerError
>> >>>> > // 48: athrow
>> >>>> > // 49: nop
>> >>>> > // 50: invokestatic 77
>> >>>> > com/foo/aspect/EventDispatcherAspect:aspectOf
>> >>>> > ()Lcom/foo/aspect/EventDispatcherAspect;
>> >>>> > // 53: getstatic 79 com/foo/listener/MyListener1:ajc$tjp_0
>> >>>> > Lorg/aspectj/lang/JoinPoint$StaticPart;
>> >>>> > // 56: invokevirtual 83
>> >>>> >
>> >>>> >
>> >>>> > com/foo/aspect/EventDispatcherAspect:ajc$after$com_foo_aspect_EventDispatcherAspect$1$5b3bc9fd
>> >>>> > (Lorg/aspectj/lang/JoinPoint$StaticPart;)V
>> >>>> > // 59: aload_0
>> >>>> > // 60: athrow
>> >>>> > // 61: invokestatic 77
>> >>>> > com/foo/aspect/EventDispatcherAspect:aspectOf
>> >>>> > ()Lcom/foo/aspect/EventDispatcherAspect;
>> >>>> > // 64: getstatic 79 com/foo/listener/MyListener1:ajc$tjp_0
>> >>>> > Lorg/aspectj/lang/JoinPoint$StaticPart;
>> >>>> > // 67: invokevirtual 83
>> >>>> >
>> >>>> >
>> >>>> > com/foo/aspect/EventDispatcherAspect:ajc$after$com_foo_aspect_EventDispatcherAspect$1$5b3bc9fd
>> >>>> > (Lorg/aspectj/lang/JoinPoint$StaticPart;)V
>> >>>> > // 70: return
>> >>>> > //
>> >>>> > // Exception table:
>> >>>> > // from to target type
>> >>>> > // 33 36 36 java/lang/Throwable
>> >>>> > }
>> >>>> >
>> >>>> > Regards,
>> >>>> > Mohammad
>> >>>> > --------------------------
>> >>>> > Sun Certified Web Developer
>> >>>> > ExpertsExchange Certified, Master:
>> >>>> > http://www.experts-exchange.com/M_1938796.html
>> >>>> > Have a look at some pictures @ http://pixelshot.wordpress.com/
>> >>>> > Do you like to read, see http://brainable.blogspot.com/
>> >>>> > For the Persians see http://fekre-motefavet.blogspot.com/
>> >>>> > English
>> >>>> >
>> >>>> >
>> >>>> > Forum:http://n2.nabble.com/English-Phrase-Finder-For-Persians-f3274251.html
>> >>>> >
>> >>>> >
>> >>>> >
>> >>>> >
>> >>>> > On Tue, Apr 27, 2010 at 7:33 PM, Simone Gianni <simoneg@xxxxxxxxxx>
>> >>>> > wrote:
>> >>>> >>
>> >>>> >> Hi Mohammad,
>> >>>> >> staticinitialization has no target object because when a class is
>> >>>> >> initialized there is no instance yet. Probably you can obtain the
>> >>>> >> class and
>> >>>> >> other informations using ThisJoinPointStaticPart inside your
>> >>>> >> advice.
>> >>>> >>
>> >>>> >> pointcut observerMethods():
>> >>>> >> staticinitialization(@Observer com..*);
>> >>>> >>
>> >>>> >> after(): observerMethods() {
>> >>>> >> InitializerSignature initsig =
>> >>>> >> (InitializerSignature)ThisJoinPointStaticPart.getSignature();
>> >>>> >> Class klass = initsig.getDeclaringType();
>> >>>> >> // adding 'klass' into Registry
>> >>>> >> }
>> >>>> >>
>> >>>> >> See
>> >>>> >> http://www.eclipse.org/aspectj/doc/released/runtime-api/index.html
>> >>>> >> for
>> >>>> >> more info.
>> >>>> >>
>> >>>> >> Simone
>> >>>> >>
>> >>>> >> 2010/4/27 Mohammad Norouzi <mnrz57@xxxxxxxxx>
>> >>>> >>>
>> >>>> >>> Hello
>> >>>> >>> I want to register those classes annotated with @Observer in a
>> >>>> >>> Registry
>> >>>> >>> class... I want this occurs in a static block of such classes:
>> >>>> >>>
>> >>>> >>> pointcut observerMethods(Class klass):
>> >>>> >>> staticinitialization(@Observer com..*)
>> >>>> >>> && target(klass);
>> >>>> >>>
>> >>>> >>> after(Class klass): observerMethods(klass) {
>> >>>> >>> // adding 'klass' into Registry
>> >>>> >>>
>> >>>> >>> }
>> >>>> >>>
>> >>>> >>> but as I read in manual it is said staticinitialization has no
>> >>>> >>> target
>> >>>> >>> object... is this right? if yes, how can I obtain the Class of
>> >>>> >>> those
>> >>>> >>> classes. Can I declare a static-block for matching classes?
>> >>>> >>>
>> >>>> >>> thanks
>> >>>> >>>
>> >>>> >>> Regards,
>> >>>> >>> Mohammad
>> >>>> >>> --------------------------
>> >>>> >>> Sun Certified Web Developer
>> >>>> >>> Have a look at some pictures @ http://pixelshot.wordpress.com/
>> >>>> >>>
>> >>>> >>>
>> >>>> >>>
>> >>>> >>> _______________________________________________
>> >>>> >>> aspectj-users mailing list
>> >>>> >>> aspectj-users@xxxxxxxxxxx
>> >>>> >>> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>> >>>> >>>
>> >>>> >>
>> >>>> >>
>> >>>> >> _______________________________________________
>> >>>> >> aspectj-users mailing list
>> >>>> >> aspectj-users@xxxxxxxxxxx
>> >>>> >> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>> >>>> >>
>> >>>> >
>> >>>> >
>> >>>> > _______________________________________________
>> >>>> > aspectj-users mailing list
>> >>>> > aspectj-users@xxxxxxxxxxx
>> >>>> > https://dev.eclipse.org/mailman/listinfo/aspectj-users
>> >>>> >
>> >>>> >
>> >>>> _______________________________________________
>> >>>> aspectj-users mailing list
>> >>>> aspectj-users@xxxxxxxxxxx
>> >>>> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>> >>>
>> >>
>> >>
>> >> _______________________________________________
>> >> aspectj-users mailing list
>> >> aspectj-users@xxxxxxxxxxx
>> >> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>> >>
>> >
>> >
>> >
>> > --
>> > Regards,
>> > Mohammad
>> > --------------------------
>> > Sun Certified Web Developer
>> > ExpertsExchange Certified, Master:
>> > http://www.experts-exchange.com/M_1938796.html
>> > Have a look at some pictures @ http://pixelshot.wordpress.com/
>> > Do you like to read, see http://brainable.blogspot.com/
>> > For the Persians see http://fekre-motefavet.blogspot.com/
>> > English
>> >
>> > Forum:http://n2.nabble.com/English-Phrase-Finder-For-Persians-f3274251.html
>> >
>> >
>> > _______________________________________________
>> > aspectj-users mailing list
>> > aspectj-users@xxxxxxxxxxx
>> > https://dev.eclipse.org/mailman/listinfo/aspectj-users
>> >
>> >
>> _______________________________________________
>> aspectj-users mailing list
>> aspectj-users@xxxxxxxxxxx
>> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>
>
>
> --
> Regards,
> Mohammad
> --------------------------
> Sun Certified Web Developer
> ExpertsExchange Certified, Master:
> http://www.experts-exchange.com/M_1938796.html
> Have a look at some pictures @ http://pixelshot.wordpress.com/
> Do you like to read, see http://brainable.blogspot.com/
> For the Persians see http://fekre-motefavet.blogspot.com/
> English
> Forum:http://n2.nabble.com/English-Phrase-Finder-For-Persians-f3274251.html
>
>
> _______________________________________________
> aspectj-users mailing list
> aspectj-users@xxxxxxxxxxx
> https://dev.eclipse.org/mailman/listinfo/aspectj-users
>
>
