package btp.oneP;

import java.lang.reflect.InvocationHandler;

import java.lang.reflect.Method;

import java.lang.reflect.Proxy;

import java.util.HashMap;

import java.util.Map;

public class DynamicProxyMixin {

public static void main(String[] args) {

}

}

class MixinProxy implements InvocationHandler{

Map<String,Object> delegatesByMethod;

public MixinProxy(TwoTuple<Object,Class<?>>...pairs){

this.delegatesByMethod = new HashMap<String,Object>();

for(TwoTuple<Object,Class<?>> pair:pairs){

for(Method m : pair.second.getMethods()){

String methodName = m.getName();

if(!this.delegatesByMethod.containsKey(methodName)){

this.delegatesByMethod.put(methodName, pair.first);

}

}

}

}

@Override

public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

String methodName = method.getName();

Object delegate = this.delegatesByMethod.get(methodName);

return method.invoke(delegate, args);

}

public static Object newInstance(TwoTuple...pairs){

Class[] interfaces = new Class[pairs.length];

for(int i=0;i<pairs.length;i++){

interfaces[i] = (Class) pairs[i].second;

}

ClassLoader cl = pairs[0].first.getClass().getClassLoader();

return Proxy.newProxyInstance(cl, interfaces, new MixinProxy(pairs));

}

}

class TwoTuple<K,V>{

K first;

V second;

public TwoTuple(K k,V v){

this.first = k;

this.second = v;

}

}