[jboss-user] [Javassist user questions] - Re: javassist as a profiler in jboss

[cry4dawn]

here is my transform method:

  | public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
  | 		byte[] transformed = null;
  | 		System.out.println("Loading class: " + className);
  | 		if (!className.startsWith("org/jboss")) {
  | 	        ClassPool pool = ClassPool.getDefault();
  | 	        Loader cl = new Loader(pool);
  | 	        ClassPool child = new ClassPool(pool);
  | 	        child.appendClassPath(new ClassClassPath(classBeingRedefined));
  | 	        try {
  | 		        CtClass c = child.get(className.replaceAll("/", "."));
  | 		        if (!c.isModified()) {
  | 			        CtMethod[] x = c.getMethods();
  | 			        for (CtMethod meth : x) {
  | 				        if (meth.getName().equals("finalize")) {
  | 					        try {
  | 						        meth = c.getDeclaredMethod(meth.getName());
  | 					        } catch (NotFoundException e) {
  | 						        System.out.println("finalize not found creating it");
  | 						        CtMethod m = CtNewMethod.make("public void finalize() throws Throwable { super.finalize();System.out.println(\"calling finalize\"); } ", c);
  | 						        c.addMethod(m);
  | 						        break;
  | 					        }
  | 					        System.out.println("modifing " + c.getName() + "'s finalize method");
  | 					        meth.insertBefore("{ System.out.println(\"calling finalize\"); }");
  | 				        }
  | 			        }
  | 			        return c.toBytecode();
  | 		        }
  | 	        } catch (Exception e) {
  | 		        e.printStackTrace();
  | 	        }
  |         }
  | 		return transformed;
  | 	}
  | 

which throws:



  | Loading class: java/io/ObjectStreamClass$FieldReflector
  | finalize not found creating it
  | Loading class: sun/reflect/GeneratedSerializationConstructorAccessor2
  | java.lang.NullPointerException
  |         at javassist.ClassClassPath.find(ClassClassPath.java:84)
  |         at javassist.ClassPoolTail.find(ClassPoolTail.java:317)
  |         at javassist.ClassPool.find(ClassPool.java:495)
  |         at javassist.ClassPool.createCtClass(ClassPool.java:479)
  |         at javassist.ClassPool.get0(ClassPool.java:445)
  |         at javassist.ClassPool.get(ClassPool.java:414)
  |         at com.healthmarkets.profiler.Xformer.transform(Xformer.java:37)
  |         at sun.instrument.TransformerManager.transform(TransformerManager.java:122)
  |         at sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:155)
  |         at sun.misc.Unsafe.defineClass(Native Method)
  |         at sun.reflect.ClassDefiner.defineClass(ClassDefiner.java:45)
  |         at sun.reflect.MethodAccessorGenerator$1.run(MethodAccessorGenerator.java:381)
  |         at java.security.AccessController.doPrivileged(Native Method)
  |         at sun.reflect.MethodAccessorGenerator.generate(MethodAccessorGenerator.java:377)
  |         at sun.reflect.MethodAccessorGenerator.generateSerializationConstructor(MethodAccessorGenerat
  | or.java:95)
  |         at sun.reflect.ReflectionFactory.newConstructorForSerialization(ReflectionFactory.java:313)
  |         at java.io.ObjectStreamClass.getSerializableConstructor(ObjectStreamClass.java:1272)
  |         at java.io.ObjectStreamClass.access$1400(ObjectStreamClass.java:47)
  |         at java.io.ObjectStreamClass$2.run(ObjectStreamClass.java:393)
  |         at java.security.AccessController.doPrivileged(Native Method)
  |         at java.io.ObjectStreamClass.<init>(ObjectStreamClass.java:373)
  |         at java.io.ObjectStreamClass.lookup(ObjectStreamClass.java:268)
  |         at java.io.ObjectStreamClass.<init>(ObjectStreamClass.java:369)
  |         at java.io.ObjectStreamClass.lookup(ObjectStreamClass.java:268)
  |         at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1029)
  |         at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:291)
  |         at javax.management.remote.rmi.RMIConnectorServer.encodeJRMPStub(RMIConnectorServer.java:715)
  | 
  |         at javax.management.remote.rmi.RMIConnectorServer.encodeStub(RMIConnectorServer.java:708)
  |         at javax.management.remote.rmi.RMIConnectorServer.encodeStubInAddress(RMIConnectorServer.java
  | :680)
  |         at javax.management.remote.rmi.RMIConnectorServer.start(RMIConnectorServer.java:438)
  |         at sun.management.jmxremote.ConnectorBootstrap.startLocalConnectorServer(ConnectorBootstrap.j
  | ava:390)
  |         at sun.management.Agent.premain(Agent.java:92)
  |         at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  |         at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  |         at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  |         at java.lang.reflect.Method.invoke(Method.java:585)
  |         at sun.management.Agent.startAgent(Agent.java:197)
  | Loading class: sun/reflect/GeneratedSerializationConstructorAccessor3
  | java.lang.NullPointerException
  |         at javassist.ClassClassPath.find(ClassClassPath.java:84)
  |         at javassist.ClassPoolTail.find(ClassPoolTail.java:317)
  |         at javassist.ClassPool.find(ClassPool.java:495)
  |         at javassist.ClassPool.createCtClass(ClassPool.java:479)
  |         at javassist.ClassPool.get0(ClassPool.java:445)
  |         at javassist.ClassPool.get(ClassPool.java:414)
  |         at com.healthmarkets.profiler.Xformer.transform(Xformer.java:37)
  |         at sun.instrument.TransformerManager.transform(TransformerManager.java:122)
  |         at sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:155)
  |         at sun.misc.Unsafe.defineClass(Native Method)
  |         at sun.reflect.ClassDefiner.defineClass(ClassDefiner.java:45)
  |         at sun.reflect.MethodAccessorGenerator$1.run(MethodAccessorGenerator.java:381)
  | 

any help would really be appreciated

View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4099277#4099277

Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4099277