Java 動態代理實現

實現流程

1、代理對象
2、介面
3、目標對象 源碼 代理對象

package com.test;import java.lang.reflect.InvocationHandler;import java.lang.reflect.Method;import java.lang.reflect.Proxy;public class Main {    public static void main(String[] args) {        // 目標對象（委派物件）        final UserServiceImpl target = new UserServiceImpl();        // UserService 介面        UserService service = (UserService) Proxy.newProxyInstance(Main.class.getClassLoader(), new Class[]{UserService.class}, new InvocationHandler() {            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {                System.out.println("執行前");                Object result = method.invoke(target, args);                System.out.println("執行後");                return result;            }        });        System.out.println(service.getAge());    }}

UserService 介面

package com.test;public interface UserService {    Boolean isAdult();    Integer getAge();}

UserServiceImpl 介面實作類別

package com.test;public class UserServiceImpl implements UserService {    public Boolean isAdult() {        return false;    }    public Integer getAge() {        return 18;    }}