BrainDeadProxyFactory.java

/*
 * Copyright 2010-2011 Ning, Inc.
 *
 * Ning licenses this file to you under the Apache License, version 2.0
 * (the "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at:
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package com.ning.billing.mock;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.HashMap;
import java.util.Map;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class BrainDeadProxyFactory {
	private static final Logger log = LoggerFactory.getLogger(BrainDeadProxyFactory.class);

	public static interface ZombieControl {
		
		public ZombieControl addResult(String method, Object result);
		
		public ZombieControl clearResults();
		
	}

	@SuppressWarnings("unchecked")
	public static <T> T createBrainDeadProxyFor(final Class<T> clazz) {
		return (T) Proxy.newProxyInstance(clazz.getClassLoader(),
                new Class[] { clazz , ZombieControl.class},
                new InvocationHandler() {
					private Map<String,Object> results = new HashMap<String,Object>();
			
					@Override
					public Object invoke(Object proxy, Method method, Object[] args)
							throws Throwable {
						
						if(method.getDeclaringClass().equals(ZombieControl.class)) {
							if(method.getName().equals("addResult")) {
								results.put((String) args[0], args[1]);
								return proxy;
							} else if(method.getName().equals("clearResults")) {
								results.clear();
								return proxy;
							}

						} else {
							
							Object result = results.get(method.getName());
							if (result != null) {
								return result;
							} else {
								log.error(String.format("No result for Method: '%s' on Class '%s'",method.getName(), method.getDeclaringClass().getName()));
								throw new UnsupportedOperationException();
							}
						}
						return (Void) null;
					}
				});
	}
}