final MethodVisitor mv = cw.visitMethod(modifier, method.getName(), getMethodSignatureAsString(returnType, parameterTypes), null, null);
mv.visitCode();
// push try/catch block, to catch declared exceptions, and to catch java.lang.Throwable
final Label l0 = new Label();
final Label l1 = new Label();
final Label l2 = new Label();
if (exceptionTypes.length > 0) {
mv.visitTryCatchBlock(l0, l1, l2, "java/lang/reflect/InvocationTargetException");
}
// push try code
mv.visitLabel(l0);
final String classNameToOverride = method.getDeclaringClass().getName().replace('.', '/');
mv.visitLdcInsn(Type.getType("L" + classNameToOverride + ";"));
// the following code generates the bytecode for this line of Java:
// Method method = <proxy>.class.getMethod("add", new Class[] { <array of function argument classes> });
// get the method name to invoke, and push to stack
mv.visitLdcInsn(method.getName());
// create the Class[]
createArrayDefinition(mv, parameterTypes.length, Class.class);
int length = 1;
// push parameters into array
for (int i = 0; i < parameterTypes.length; i++) {
// keep copy of array on stack
mv.visitInsn(DUP);
final Class<?> parameterType = parameterTypes[i];
// push number onto stack
pushIntOntoStack(mv, i);
if (parameterType.isPrimitive()) {
final String wrapperType = getWrapperType(parameterType);
mv.visitFieldInsn(GETSTATIC, wrapperType, "TYPE", "Ljava/lang/Class;");
} else {
mv.visitLdcInsn(Type.getType(getAsmTypeAsString(parameterType, true)));
}
mv.visitInsn(AASTORE);
if (Long.TYPE.equals(parameterType) || Double.TYPE.equals(parameterType)) {
length += 2;
} else {
length++;
}
}
// invoke getMethod() with the method name and the array of types
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Class", "getDeclaredMethod", "(Ljava/lang/String;[Ljava/lang/Class;)Ljava/lang/reflect/Method;", false);
// store the returned method for later
mv.visitVarInsn(ASTORE, length);
// the following code generates bytecode equivalent to:
// return ((<returntype>) invocationHandler.invoke(this, method, new Object[] { <function arguments }))[.<primitive>Value()];
final Label l4 = new Label();
mv.visitLabel(l4);
mv.visitVarInsn(ALOAD, 0);
// get the invocationHandler field from this class
mv.visitFieldInsn(GETFIELD, proxyName, handlerName, "Ljava/lang/reflect/InvocationHandler;");
// we want to pass "this" in as the first parameter
mv.visitVarInsn(ALOAD, 0);
// and the method we fetched earlier
mv.visitVarInsn(ALOAD, length);
// need to construct the array of objects passed in
// create the Object[]
createArrayDefinition(mv, parameterTypes.length, Object.class);
int index = 1;
// push parameters into array
for (int i = 0; i < parameterTypes.length; i++) {
// keep copy of array on stack
mv.visitInsn(DUP);
final Class<?> parameterType = parameterTypes[i];
// push number onto stack
pushIntOntoStack(mv, i);
if (parameterType.isPrimitive()) {
final String wrapperType = getWrapperType(parameterType);
mv.visitVarInsn(getVarInsn(parameterType), index);
mv.visitMethodInsn(INVOKESTATIC, wrapperType, "valueOf", "(" + getPrimitiveLetter(parameterType) + ")L" + wrapperType + ";", false);
mv.visitInsn(AASTORE);
if (Long.TYPE.equals(parameterType) || Double.TYPE.equals(parameterType)) {
index += 2;
} else {
index++;
}
} else {
mv.visitVarInsn(ALOAD, index);
mv.visitInsn(AASTORE);
index++;
}
}
// invoke the invocationHandler
mv.visitMethodInsn(INVOKEINTERFACE, "java/lang/reflect/InvocationHandler", "invoke", "(Ljava/lang/Object;Ljava/lang/reflect/Method;[Ljava/lang/Object;)Ljava/lang/Object;", true);
// cast the result
mv.visitTypeInsn(CHECKCAST, getCastType(returnType));
if (returnType.isPrimitive() && !Void.TYPE.equals(returnType)) {
// get the primitive value
mv.visitMethodInsn(INVOKEVIRTUAL, getWrapperType(returnType), getPrimitiveMethod(returnType), "()" + getPrimitiveLetter(returnType), false);
}
// push return
mv.visitLabel(l1);
if (!Void.TYPE.equals(returnType)) {
mv.visitInsn(getReturnInsn(returnType));
} else {
mv.visitInsn(POP);
mv.visitInsn(RETURN);
}
// catch InvocationTargetException
if (exceptionTypes.length > 0) {
mv.visitLabel(l2);
mv.visitVarInsn(ASTORE, length);
final Label l5 = new Label();
mv.visitLabel(l5);
for (int i = 0; i < exceptionTypes.length; i++) {
final Class<?> exceptionType = exceptionTypes[i];
mv.visitLdcInsn(Type.getType("L" + exceptionType.getName().replace('.', '/') + ";"));
mv.visitVarInsn(ALOAD, length);
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/reflect/InvocationTargetException", "getCause", "()Ljava/lang/Throwable;", false);
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Object", "getClass", "()Ljava/lang/Class;", false);
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/Object", "equals", "(Ljava/lang/Object;)Z", false);
final Label l6 = new Label();
mv.visitJumpInsn(IFEQ, l6);
final Label l7 = new Label();
mv.visitLabel(l7);
mv.visitVarInsn(ALOAD, length);
mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/reflect/InvocationTargetException", "getCause", "()Ljava/lang/Throwable;", false);
mv.visitTypeInsn(CHECKCAST, exceptionType.getName().replace('.', '/'));