java 动态代理

先贴代码 ，有空再写说明

package com.pattern.structure.proxy;

/**
 * 信息接口
 */
public interface Message {

    public void sendMessage(String value);

}

package com.pattern.structure.proxy;
/**
 * 邮箱实现类
 */
public class EmailMessage implements Message {

    @Override
    public void sendMessage(String value) {
        System.out.println(value);
    }

}

package com.pattern.structure.proxy;

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

/**
 * 动态代理
 */
public class DynamicProxy implements InvocationHandler {

    private Object target;

    /**
     * 绑定委托对象并返回一个代理类
     * @param target
     * @return
     */
    public Object bind(Object target) {
        this.target = target;
        // 取得代理对象 ,要绑定接口(这是一个缺陷，cglib弥补了这一缺陷)
        return Proxy.newProxyInstance(target.getClass().getClassLoader(),target.getClass().getInterfaces(), this);
    }

    @Override
    public Object invoke(Object obj, Method method, Object[] aobj)
            throws Throwable {        
        Object result = null;
        if(checkSendMessage(aobj[0])){
            result = method.invoke(target, aobj);
        }else{
            System.out.println("发送的短信为空，发不出去");
        }        
        return result;
    }    

    public boolean checkSendMessage(Object value){
        return value == null ? false : true;
    }

}

package com.pattern.structure.proxy;

public class Test {

    /**
     * @param args
     */
    public static void main(String[] args) {        
        /**************动态代理******************/
        DynamicProxy dynamicProxy =  new DynamicProxy();
        Message emailMessageProxy = (Message)dynamicProxy.bind(new EmailMessage());
        emailMessageProxy.sendMessage(null);
        emailMessageProxy.sendMessage("动态代理成功发送");
    }

}