4 Replies Latest reply on Dec 3, 2006 8:28 AM by flavia.rainone.old

Pls help with a simple Mixin problem

guava Dec 1, 2006 8:13 PM

Hi,

I'm started to use the Introduction feature of JBossAOP and can not seem to get the Mixin working. Any help will be appreciated. I have one Pojo, one Aspect, one Mixin, and an interface the mixin implements. I'm running these in the same directory as the examples provided by JbossAOP. Following are the classes:

//------ MyPojo
public class MyPojo {
}

//------ MyInf
public interface MyInf {
String hello(String h);
}

//-----MyMixin
public class MyMixin implements MyInf {
public String hello(String h) {
return "Hello " + h;
}
}

//---- MyAspect
import org.jboss.aop.Aspect;
import org.jboss.aop.Mixin;
import org.jboss.aop.Introduction;

@Aspect
public class MyAspect
{
@Mixin (target=MyPojo.class, interfaces={MyInf.class})
public static MyMixin createMyMixin() {
return new MyMixin();
}
}

I'm getting a javassist.NotFoundException: LMyMixin when I run aop compiler.

Following are the build file and the stack trace:

//--------- stack trace
[aopc] [debug] Passed in instrumentor: null
[aopc] [debug] Defaulting instrumentor to: org.jboss.aop.instrument.Classic
Instrumentor
[aopc] [debug] jboss.aop.class.path: C:\tools\jboss-aop_1.5.2.GA\docs\aspec
t-framework\examples\temp1
[aopc] [debug] Looking for aspects in: MyAspect
[aopc] [debug] Found @Aspect in: MyAspect
[aopc] [debug] Looking for aspects in: MyInf
[aopc] [debug] Looking for aspects in: MyMixin
[aopc] [debug] Looking for aspects in: MyPojo
[aopc] [debug] jboss.aop.search.classpath: 'null' true
[aopc] [debug] jboss.aop.path: null
[aopc] [trying to transform] MyMixin
[aopc] [debug] There are no caller pointcuts!
[aopc] [debug] javassist.CtMethod@ca717109[public hello (Ljava/lang/String;
)Ljava/lang/String;] matches no pointcuts
[aopc] [debug] javassist.CtConstructor@fec107[public MyMixin ()V] matches n
o pointcuts
[aopc] [debug] was MyMixin converted: false
[aopc] [no comp needed] C:\tools\jboss-aop_1.5.2.GA\docs\aspect-framework\e
xamples\temp1\MyMixin.class
[aopc] [cannot compile] isInterface: MyInf
[aopc] [no comp needed] C:\tools\jboss-aop_1.5.2.GA\docs\aspect-framework\e
xamples\temp1\MyInf.class
[aopc] [trying to transform] MyAspect
[aopc] [debug] There are no caller pointcuts!
[aopc] [debug] javassist.CtMethod@8676605a[public static createMyMixin ()LM
yMixin;] matches no pointcuts
[aopc] [debug] javassist.CtConstructor@64f6cd[public MyAspect ()V] matches
no pointcuts
[aopc] [debug] was MyAspect converted: false
[aopc] [no comp needed] C:\tools\jboss-aop_1.5.2.GA\docs\aspect-framework\e
xamples\temp1\MyAspect.class
[aopc] [trying to transform] MyPojo
[aopc] [debug] There are no caller pointcuts!
[aopc] [debug] javassist.CtConstructor@5e5a50[public MyPojo ()V] matches no
pointcuts
[aopc] javassist.NotFoundException: LMyMixin
[aopc] at javassist.ClassPool.get(ClassPool.java:416)
[aopc] at org.jboss.aop.instrument.Instrumentor.addMixin(Instrumentor.j
ava:250)
[aopc] at org.jboss.aop.instrument.Instrumentor.instrumentIntroductions
(Instrumentor.java:336)
[aopc] at org.jboss.aop.instrument.Instrumentor.transform(Instrumentor.
java:672)
[aopc] at org.jboss.aop.AspectManager.translate(AspectManager.java:908)

[aopc] at org.jboss.aop.AspectManager.transform(AspectManager.java:820)

[aopc] at org.jboss.aop.standalone.Compiler.compileFile(Compiler.java:3
45)
[aopc] at org.jboss.aop.standalone.Compiler.compile(Compiler.java:234)
[aopc] at org.jboss.aop.standalone.Compiler.main(Compiler.java:90)
[aopc] java.lang.RuntimeException: failed to transform: MyPojo
[aopc] at org.jboss.aop.instrument.Instrumentor.transform(Instrumentor.
java:732)
[aopc] at org.jboss.aop.AspectManager.translate(AspectManager.java:908)

[aopc] at org.jboss.aop.AspectManager.transform(AspectManager.java:820)

[aopc] at org.jboss.aop.standalone.Compiler.compileFile(Compiler.java:3
45)
[aopc] at org.jboss.aop.standalone.Compiler.compile(Compiler.java:234)
[aopc] at org.jboss.aop.standalone.Compiler.main(Compiler.java:90)
[aopc] Caused by: javassist.NotFoundException: LMyMixin
[aopc] at javassist.ClassPool.get(ClassPool.java:416)
[aopc] at org.jboss.aop.instrument.Instrumentor.addMixin(Instrumentor.j
ava:250)
[aopc] at org.jboss.aop.instrument.Instrumentor.instrumentIntroductions
(Instrumentor.java:336)
[aopc] at org.jboss.aop.instrument.Instrumentor.transform(Instrumentor.
java:672)
[aopc] ... 5 more
[aopc] Exception in thread "main" java.lang.RuntimeException: failed to tra
nsform: MyPojo
[aopc] at org.jboss.aop.instrument.Instrumentor.transform(Instrumentor.
java:732)
[aopc] at org.jboss.aop.AspectManager.translate(AspectManager.java:908)

[aopc] at org.jboss.aop.AspectManager.transform(AspectManager.java:820)

[aopc] at org.jboss.aop.standalone.Compiler.compileFile(Compiler.java:3
45)
[aopc] at org.jboss.aop.standalone.Compiler.compile(Compiler.java:234)
[aopc] at org.jboss.aop.standalone.Compiler.main(Compiler.java:90)
[aopc] Caused by: javassist.NotFoundException: LMyMixin
[aopc] at javassist.ClassPool.get(ClassPool.java:416)
[aopc] at org.jboss.aop.instrument.Instrumentor.addMixin(Instrumentor.j
ava:250)
[aopc] at org.jboss.aop.instrument.Instrumentor.instrumentIntroductions
(Instrumentor.java:336)
[aopc] at org.jboss.aop.instrument.Instrumentor.transform(Instrumentor.
java:672)
[aopc] ... 5 more

BUILD FAILED
C:\tools\jboss-aop_1.5.2.GA\docs\aspect-framework\examples\temp1\build.xml:33: J
ava returned: 1

//----- build.xml (identical to JBossAOP example jboss-aop_1.5.2.GA\docs\aspect-framework\examples\annotated-introduction)
<?xml version="1.0" encoding="UTF-8"?>

1. Re: Pls help with a simple Mixin problem

fabiocsilva Dec 2, 2006 8:14 AM (in response to guava)

You can remove the archives .class before compiling the sources. I use a modified version of build file. Try:

<?xml version="1.0" encoding="UTF-8"?>

<project default="run" name="JBossAOP">
 <property name="jboss.aop.root" value="/opt/project/library/jboss-aop"/>
 <property name="jboss.aop.lib50" value="${jboss.aop.root}/lib-50"/>
 <property name="buildpath" value="${basedir}/bin"/>
 <property name="class.main" value="Driver"/>

 <target name="prepare">

 <path id="jboss.aop.classpath50">
 <fileset dir="${jboss.aop.lib50}">
 <include name="*.jar"/>
 </fileset>
 </path>

 <path id="classpath">
 <path refid="jboss.aop.classpath50"/>
 <pathelement path="."/>
 </path>

 <property name="aop50jar" value="${jboss.aop.lib50}/jboss-aop-jdk50.jar"/>

 <path id="classpath50">
 <path refid="jboss.aop.classpath50"/>
 <pathelement path="."/>
 </path>

 <taskdef name="aopc" classname="org.jboss.aop.ant.AopC" classpathref="jboss.aop.classpath50"/>
 </target>

 <target name="clean">
 <delete dir="${buildpath}" />
 <mkdir dir="${buildpath}" />
 </target>

 <target name="compile" depends="prepare">
 <javac srcdir="."
 destdir="${buildpath}"
 debug="on"
 deprecation="on"
 optimize="off"
 includes="**">
 <classpath refid="classpath"/>
 </javac>
 <aopc compilerclasspathref="classpath" classpathref="classpath" verbose="true">
 <classpath path="${buildpath}"/>
 <src path="."/>
 <aopclasspath path="."/>
 </aopc>
 </target>

 <target name="run" depends="clean,compile">
 <java fork="yes" failOnError="true" className="${class.main}">
 <sysproperty key="jboss.aop.class.path" value="."/>
 <classpath refid="classpath"/>
 <classpath path="${buildpath}"/>
 </java>
 </target>

 <target name="compile50standalone" depends="prepare">
 <javac srcdir="."
 destdir="."
 debug="on"
 deprecation="on"
 optimize="off"
 includes="**">
 <classpath refid="classpath50"/>
 </javac>
 </target>

 <target name="run.50.instrumented" depends="compile50standalone">
 <java fork="yes" failOnError="true" className="${class.main}">
 <sysproperty key="jboss.aop.class.path" value="."/>
 <jvmarg value="-javaagent:${aop50jar}"/>
 <classpath path="${buildpath}"/>
 <classpath refid="classpath50"/>
 </java>
 </target>

</project>

2. Re: Pls help with a simple Mixin problem

flavia.rainone.old Dec 2, 2006 7:12 PM (in response to guava)
The problem is in your aspect code:

@Aspect public class MyAspect { @Mixin (target=MyPojo.class, interfaces={MyInf.class}) public static MyMixin createMyMixin() { return new MyMixin(); } }

The createMyMixin method must receive the pojo as an argument. Just replace your aspect by this new one.

@Aspect public class MyAspect { @Mixin (target=MyPojo.class, interfaces={MyInf.class}) public static MyMixin createMyMixin(MyPojo pojo) { return new MyMixin(); } }
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3. Re: Pls help with a simple Mixin problem

guava Dec 3, 2006 3:14 AM (in response to guava)

Thanks so much.

Indeed it worked after I changed the Mixin method to take MyPojo as an input argument.

I was wonder why this has to be the case though.

I can not see from the AOP document that the mixin creation method has to take the opriginal pojo as the argument.

From Section 5.6 @Mixin the document only specifies 4 requirements:

* be public
* be static
* contain the logic to create the mixin class
* return an instance of the mixin class

Perhaps they should add one more requirement or someone can explain why this is the case?

Thanks.
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4. Re: Pls help with a simple Mixin problem

flavia.rainone.old Dec 3, 2006 8:28 AM (in response to guava)

Indeed, we forgot to add this requirement to the documentation.
It will be fixed on the next release.
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