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public interface UserService {

    //用于实现业务的方法

    public void save();

}

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public class UserServiceImpl implements UserService{

    @Override

    public void save() {

        System.out.println("save user!!");

    }

}

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public class UserServiceProxy implements UserService{

    //代理角色内部要有真实角色的引用

    private UserServiceImpl realRole = new UserServiceImpl();

    @Override

    public void save() {

        preHandle();

        realRole.save();

        postHandle();

    }

    /**

     * 代理类特有的方法

     */

    private void preHandle(){

        System.out.println("preHandle");

    }

    /**

     * 代理类特有的方法

     */

    private void postHandle(){

        System.out.println("postHandle");

    }

}

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public class ProxyTest {

    public static void main(String[] args) {

        UserService userService = new UserServiceProxy();

        userService.save();

    }

}