接口类UserDao：

package com.ant.jdk8.proxy;public interface UserDao {    void save();}

接口类EmployeeDao：

package com.ant.jdk8.proxy;public interface EmployeeDao {    void add();}

目标类UserDaoImpl：

package com.ant.jdk8.proxy;public class UserDaoImpl implements UserDao {    @Override    public void save() {        System.out.println("保存用户");    }}

目标类EmployeeDaoImpl：

package com.ant.jdk8.proxy;public class EmployeeDaoImpl implements EmployeeDao {    @Override    public void add() {        System.out.println("添加雇员信息");    }}

代理类ProxyFactory：

package com.ant.jdk8.proxy;import java.lang.reflect.InvocationHandler;import java.lang.reflect.Method;import java.lang.reflect.Proxy;public class ProxyFactory {    //维护一个目标对象    private Object target;    public ProxyFactory(Object target){        this.target = target;    }    //生成目标对象的代理对象    public Object getProxyInstance(){        return Proxy.newProxyInstance(                target.getClass().getClassLoader(),                target.getClass().getInterfaces(),                new InvocationHandler(){                    @Override                    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {                        System.out.println("---开始事务---");                        Object object = method.invoke(target, args);                        System.out.println("---提交事务---");                        return object;                    }                });    }}

测试类APP：

package com.ant.jdk8.proxy;public class App {    public static void main(String[] args) {        //目标对象        UserDao target = new UserDaoImpl();        //代理对象        UserDao proxy = (UserDao) new ProxyFactory(target).getProxyInstance();        proxy.save();        System.out.println("==========================");        //目标对象        EmployeeDao target2 = new EmployeeDaoImpl();        //代理对象        EmployeeDao proxy2 = (EmployeeDao)new ProxyFactory(target2).getProxyInstance();        proxy2.add();    }}

JDK动态代理总结：

代理对象不需要实现接口，但是目标对象一定要实现接口，否则不能用动态代理。