MethodCreator

private void generateMethodHeader(int access, String name, String desc, String signature, String[] exceptions, List<AnnotationDescriptor> annotations, Map<Integer, List<AnnotationDescriptor>> paramAnnotations) {
        GeneratorAdapter mv = new GeneratorAdapter(cv.visitMethod(access, name, desc, signature, exceptions), access, name, desc);


        mv.visitCode();

        Type returnType = Type.getReturnType(desc);

        // Compute result and exception stack location
        // We also compute the actual Thread stack, when it requires the returned object.
        int result = -1;
        List<Object> stack = new ArrayList<Object>();
        stack.add(m_owner);
        if (returnType.getSort() != Type.VOID) {
            // The method returns something
            result = mv.newLocal(returnType);
            switch (returnType.getSort()) {
                case Type.INT:
                case Type.CHAR:
                case Type.BOOLEAN:
                case Type.BYTE:
                    stack.add(Opcodes.INTEGER);
                    break;
                case Type.DOUBLE:
                    stack.add(Opcodes.DOUBLE);
                    break;
                case Type.FLOAT:
                    stack.add(Opcodes.FLOAT);
                    break;
                case Type.LONG:
                    stack.add(Opcodes.LONG);
                    break;
                case Type.OBJECT:
                case Type.ARRAY:
                    stack.add(returnType.getInternalName().toString());
                    break;
            }
        }
        int exception = mv.newLocal(Type.getType(Throwable.class));

        Label l0 = new Label();
        Label l1 = new Label();
        Label l2 = new Label();

        mv.visitTryCatchBlock(l0, l1, l2, "java/lang/Throwable");

        // Not intercepted method:
        mv.visitFrame(Opcodes.F_NEW, 1, new Object[]{m_owner}, 0, new Object[]{});
        mv.visitVarInsn(ALOAD, 0);
        mv.visitFieldInsn(GETFIELD, m_owner, generateMethodFlag(name, desc), "Z");
        mv.visitJumpInsn(IFNE, l0);

        mv.visitVarInsn(ALOAD, 0);
        mv.loadArgs();
        mv.visitMethodInsn(INVOKESPECIAL, m_owner, PREFIX + name, desc);
        mv.visitInsn(returnType.getOpcode(IRETURN));
        // end of the non intercepted method invocation.

        // Beginning of the try / catch clause
        mv.visitLabel(l0);

        mv.visitFrame(Opcodes.F_NEW, 1, new Object[]{m_owner}, 0, new Object[]{});

        // onEntry call
        mv.visitVarInsn(ALOAD, 0);
        mv.visitFieldInsn(GETFIELD, m_owner, IM_FIELD, "Lorg/apache/felix/ipojo/InstanceManager;");
        mv.visitVarInsn(ALOAD, 0);
        mv.visitLdcInsn(generateMethodId(name, desc));
        mv.loadArgArray();
        mv.visitMethodInsn(INVOKEVIRTUAL, "org/apache/felix/ipojo/InstanceManager", ENTRY, "(Ljava/lang/Object;Ljava/lang/String;[Ljava/lang/Object;)V");
        // End of onEntry call
        mv.visitVarInsn(ALOAD, 0);

        // Actual call of the method
        // Do not allow argument modification : just reload arguments.
        mv.loadArgs();
        mv.visitMethodInsn(INVOKESPECIAL, m_owner, PREFIX + name, desc);

        if (returnType.getSort() != Type.VOID) {
            mv.visitVarInsn(returnType.getOpcode(ISTORE), result);
        }
        // End of the actual call of the method

        // onExit call
        mv.visitVarInsn(ALOAD, 0);
        mv.visitFieldInsn(GETFIELD, m_owner, IM_FIELD, "Lorg/apache/felix/ipojo/InstanceManager;");
        mv.visitVarInsn(ALOAD, 0);
        mv.visitLdcInsn(generateMethodId(name, desc));
        if (returnType.getSort() != Type.VOID) {
            mv.visitVarInsn(returnType.getOpcode(ILOAD), result);
            mv.box(returnType);
        } else {
            mv.visitInsn(ACONST_NULL);
        }
        mv.visitMethodInsn(INVOKEVIRTUAL, "org/apache/felix/ipojo/InstanceManager", EXIT, "(Ljava/lang/Object;Ljava/lang/String;Ljava/lang/Object;)V");
        // enf of the onExit call
        mv.visitLabel(l1);
        Label l7 = new Label();
        mv.visitJumpInsn(GOTO, l7);

        // Catch clause
        mv.visitLabel(l2);
        mv.visitFrame(Opcodes.F_NEW, stack.size(), stack.toArray(new Object[0]), 1, new Object[]{"java/lang/Throwable"});

        mv.visitVarInsn(ASTORE, exception);
        mv.visitVarInsn(ALOAD, 0);
        mv.visitFieldInsn(GETFIELD, m_owner, IM_FIELD, "Lorg/apache/felix/ipojo/InstanceManager;");
        mv.visitVarInsn(ALOAD, 0);
        mv.visitLdcInsn(generateMethodId(name, desc));
        mv.visitVarInsn(ALOAD, exception);
        mv.visitMethodInsn(INVOKEVIRTUAL, "org/apache/felix/ipojo/InstanceManager", ERROR, "(Ljava/lang/Object;Ljava/lang/String;Ljava/lang/Throwable;)V");
        mv.visitVarInsn(ALOAD, exception);
        mv.visitInsn(ATHROW);
        // Enf ot the catch clause.

        // End of the method (just return)
        mv.visitLabel(l7);

        if (returnType.getSort() != Type.VOID) {
            mv.visitFrame(Opcodes.F_NEW, stack.size(), stack.toArray(new Object[0]), 0, new Object[]{});
            mv.visitVarInsn(returnType.getOpcode(ILOAD), result);
        } else {
            mv.visitFrame(Opcodes.F_NEW, 1, new Object[]{m_owner}, 0, new Object[]{});
        }
        mv.visitInsn(returnType.getOpcode(IRETURN));

        // ----- Move Annotations ---

        // Move annotations
        if (annotations != null) {
            for (int i = 0; i < annotations.size(); i++) {
                AnnotationDescriptor ad = annotations.get(i);
                ad.visitAnnotation(mv);
            }
        }

        // Move parameter annotations
        if (paramAnnotations != null && !paramAnnotations.isEmpty()) {
            Iterator<Integer> ids = paramAnnotations.keySet().iterator();
            while (ids.hasNext()) {
                Integer id = ids.next();
                List<AnnotationDescriptor> ads = paramAnnotations.get(id);
                for (int i = 0; i < ads.size(); i++) {
                    AnnotationDescriptor ad = ads.get(i);
                    ad.visitParameterAnnotation(id.intValue(), mv);
                }
            }
        }

        mv.visitMaxs(0, 0);
        mv.visitEnd();
    }