java 动态代理简单实现

java 动态代理简单实现

Java  /  管理员 发布于 2020-03-08 13:33:15   53

dynamicproxy.service.HelloService

package dynamicproxy.service;public interface HelloService {public void sayHello();}

 

dynamicproxy.service.impl.HelloServiceImpl

package dynamicproxy.service.impl;import dynamicproxy.service.HelloService;public class HelloServiceImpl implements HelloService {@Overridepublic void sayHello() {System.out.println("hello everyone ... ");}}

 

dynamicproxy.handler.LogHandler

package dynamicproxy.handler;import java.lang.reflect.InvocationHandler;import java.lang.reflect.Method;public class LogHandler implements InvocationHandler {private Object target = null;public LogHandler(Object target) {this.target = target;}private void doBefore(){System.out.println("do before ... ");}private void doAfter(){System.out.println("do after ... ");}@Overridepublic Object invoke(Object proxy, Method method, Object[] args)throws Throwable {doBefore();Object res = method.invoke(target, args);doAfter();return res;}}

 

dynamicproxy.test.Main

package dynamicproxy.test;import java.lang.reflect.InvocationHandler;import java.lang.reflect.Proxy;import dynamicproxy.handler.LogHandler;import dynamicproxy.service.HelloService;import dynamicproxy.service.impl.HelloServiceImpl;public class Main {public static void main(String[] args) {HelloService target = new HelloServiceImpl();InvocationHandler handler = new LogHandler(target);HelloService helloService = (HelloService) Proxy.newProxyInstance(target.getClass().getClassLoader(), target.getClass().getInterfaces(), handler);helloService.sayHello();}}