ObjectInput

[slv]

Hello,
I am currently playing around with JBoss AOP, but I can't seem to make my pointcuts work.

This is the xml file:

<aop>
 <aspect class="main.Aspect" />
 <bind pointcut="execution(void $instanceof{java.io.ObjectOutput}->writeObject($instanceof{java.lang.Object}))">
 <around aspect="main.Aspect" name="secureWrite" />
 </bind>
 <bind pointcut="execution($instanceof{java.lang.Object} $instanceof{java.io.ObjectInput}->readObject())">
 <around aspect="main.Aspect" name="secureRead" />
 </bind>
</aop>

My Aspect class is this:

package main;

import org.jboss.aop.joinpoint.MethodInvocation;

public class Aspect {
 private final SecureCommunication secure;

 public Aspect() {
 secure = new SecureCommunicationRSA();
 }

 public Object secureWrite(MethodInvocation invocation) throws Throwable {
 System.out.println("Writing secure");
 Object[] args = invocation.getArguments();
 for (int i = 0; i < args.length; i++) {
 args = secure.encrypt(args);
 }
 return invocation.invokeNext();
 }

 public Object secureRead(MethodInvocation invocation) throws Throwable {
 System.out.println("Reading secure");
 return secure.decrypt(invocation.invokeNext());
 }
}

And the class I want to instrument is this:

package main;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.ObjectOutputStream;

public class Main {

 /**
 * @param args
 */
 public static void main(String[] args) throws IOException,
 ClassNotFoundException {
 ObjectOutput out = new ObjectOutputStream(new FileOutputStream(
 new File("test")));
 out.writeObject("this");
 out.writeObject("is");
 out.writeObject("a test");
 out.close();

 ObjectInput in = new ObjectInputStream(new FileInputStream(new File(
 "test")));
 System.out.println(in.readObject());
 System.out.println(in.readObject());
 System.out.println(in.readObject());

 }

}

When I try to apply the aspects, I get the following message

[aop-debug] org.jboss.aop.instrument.Instrumentor trying to transform main.Main
[aop-debug] org.jboss.aop.instrument.CallerTransformer There are no caller pointcuts!
[aop-debug] org.jboss.aop.instrument.JoinpointSimpleClassifier javassist.CtMethod@44a4fe33[public static main ([Ljava/lang/String;)V] matches no pointcuts
[aop-debug] org.jboss.aop.instrument.JoinpointSimpleClassifier javassist.CtConstructor@176e552[public Main ()V] matches no pointcuts
[aop-debug] org.jboss.aop.instrument.Instrumentor was main.Main converted: false
[no comp needed] /home/slv/Desktop/EncryptionTest/classes/main/Main.class

Can you please help me? I tried so many things and I can't make it work.

Thank you,
Silviu

[kabirkhan]

You cannot weave java system classes
http://www.jboss.org/jbossaop/docs/2.0.0.GA/docs/aspect-framework/examples/caller/caller.html
This example also exists in the JBoss AOP download

[slv]

Thanks for the reply!
I still have one question:
Accord to this (http://www.jboss.org/jbossaop/docs/2.0.0.GA/docs/aspect-framework/examples/method-execution/methodexecution.html) I should be able to access the arguments and change them, but I cannot.

When an AOP'ed method is called, JBoss will break up the method into its parts: a java.lang.reflect.Method object and an

Object[]

array representing the arguments of the method. These parts are encapsulated in an org.jboss.aop.joinpoint.Invocation object. SimpleInterceptor.java is a simple implementation of an interceptor.

Any idea on how to do that?

Thanks so much,
Silviu

[kabirkhan]

interceptor method:

public Object invoke(Invocation inv) throws Exception
{
 MethodInvocation mi = (MethodInvocation)inv;
 Object[] args = mi.getArguments();
 args[0] = "Changed"; //Must be of the same type as the original parameter
 mi.setArguments(args);
}