接口

package com.struts2.interceptorDemo;

/**
 * @author Administrator
 *
 */
public interface Dog {
    //两个方法的声明
    public void info();
    public void run();
}

接口的实现类

package com.struts2.interceptorDemo;

/**
 * @author Administrator
 *
 */
public class DogImpl implements Dog{
    public void info() {
        System.out.println("INFO");
    }

    public void run() {
        System.out.println("RUN");
    }
}

拦截器的定义

package com.struts2.interceptorDemo;

public class DogInterceptor {
    //第一个拦截器
    public void method1(){
        System.out.println("模拟方法1");
    }
    //第二个拦截器
    public void method2(){
        System.out.println("模拟方法2");
    }
}

代理工厂

package com.struts2.interceptorDemo;

import java.lang.reflect.Proxy;

public class MyProxyFactory {
    public static Object getProxy(Object o){
        ProxyHandle handle=new ProxyHandle();
        handle.setTarget(o);
        return Proxy.newProxyInstance(DogImpl.class.getClassLoader(), o.getClass().getInterfaces(), handle);
    }
}

handle类

package com.struts2.interceptorDemo;

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

public class ProxyHandle implements InvocationHandler {
    private Object target;
    DogInterceptor dogInterceptor=new DogInterceptor();
    public Object invoke(Object proxy, Method method, Object[] args)
    throws Throwable {
        Object result=null;
        if(method.getName().equals("INFO")){
            dogInterceptor.method1();
            result=method.invoke(target, args);
            dogInterceptor.method2();
        }else{
            result=method.invoke(target, args);
        }
        return result;
    }
    public void setTarget(Object o) {
        this.target = o;
    }
}

测试类

package com.struts2.interceptorDemo;

public class TestDog {
    /**
     * @param args
     */
    public static void main(String[] args) {
        //创建一个实例
        Dog dogProxy=new DogImpl();
        Dog dog=null;
        Object proxy=MyProxyFactory.getProxy(dogProxy);
        if(proxy instanceof Dog){
            dog=(Dog)proxy;
        }
        dog.info();
        dog.run();
    }
}