I'm using the asm library to perform some Java bytecode modification - specifically to modify my classes to implement a new interface and associated methods. My current approach is using the core asm API via a javaagent. I'd like to keep this dynamic approach as opposed to statically modifying .class files.

At a higher level, my problem is that if I choose to modify class A, which extends from B, I also need to modify B. (Given my understanding of how classes are loaded in the JVM, I believe that class B will always be handed to a transformer before class A. (Please correct me if I'm wrong). Given that assumption, I'm thinking that I then need to go back and retransform B. My approach is captured in this bit of code:

public byte[] transform(ClassLoader l, String name, Class<?> clazz, ProtectionDomain d, byte[] b) {
      throws IllegalClassFormatException {
    // **1**
    System.out.println("--->>> " + name);

    if (interestingClass(name)) {
        try {
            ClassReader cr = new ClassReader(b);
            ClassWriter cw = new ClassWriter(cr, ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);
            PyClassVisitorAdapter pv = new PyClassVisitorAdapter(cw, name);
            cr.accept(pv, 0);

            // **2** Retrieve the superclass and try to transform that
            if (! "Ljava/lang/Object;".equals(pv.getSuperName())) {
                String cName = classJvmToCanonical(pv.getSuperName());
                Class[] classes = inst.getAllLoadedClasses();
                for (Class c : classes) {
                    if (c.getName().equals(cName)) {
                        inst.retransformClasses(c);
                        break;
                    }
                }
            }

            // Dump the transformed class
            ClassReader cr2 = new ClassReader(cw.toByteArray());
            ClassWriter cw2 = new ClassWriter(cr2, 0);
            TraceClassVisitor tcv = new TraceCl
java bytecode java-bytecode-asm
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