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A pure Java library that provides many tools, utils, and functions.

There is a newer version: 1.2.6

/**
 * Copyright Sp42 [email protected]
 *
 * Licensed 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.ajaxjs.ioc.aop;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Objects;

/**
 * AOP 抽象类
 * 
 * @author sp42 [email protected]
 * @param  T 必须是目标对象的其中一个接口类型
 */
public class Aop implements InvocationHandler {
	/**
	 * 原目标对象，未被 AOP 包装过的
	 */
	private T target;

	private AopHandler[] handlers;

	/**
	 * 对目标对象进行 AOP 处理，AOP所在的模块，就是本类！
	 * 
	 * @param target 目标对象，被 AOP 接管的对象
	 * @return AOP 代理对象，已经不是原来目标对象了，但是同一接口的
	 */
	
	/**
	 * 
	 * @param target
	 * @param handlers 绑定多个代理处理器
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public T bind(T target, AopHandler... handlers) {
		Objects.toString(target, "proxy 对象不能为空！");

		this.target = target;
		this.handlers = handlers;

		Object obj = Proxy.newProxyInstance(target.getClass().getClassLoader(), target.getClass().getInterfaces(),
				this);
		return (T) obj;
	}

	@Override
	public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
		for (AopHandler handler : handlers) {
			Object beforeReturn = handler.before(target, method, method == null ? null : method.getName(), args);

			if (beforeReturn instanceof ReturnBefore)
				return ((ReturnBefore) beforeReturn).getReturnValue(); // 中止运行 aop
			// 如果作为参数
			boolean isBeforeReturn = beforeReturn != null && beforeReturn instanceof ReturnAsArg;

			if (isBeforeReturn)
				args = ((ReturnAsArg) beforeReturn).getArgs();
		}

		Object returnObj = method.invoke(target, args);
		String methodName = method == null ? null : method.getName();

		for (AopHandler handler : handlers)
			handler.after(target, method, methodName, args, returnObj);

		return returnObj;
	}
}