12、设计模式(结构型)之代理模式

深藏阁楼爱情的钟 2022-05-11 07:44 199阅读 0赞

### 作用 ###

*  为其他对象提供一种代理以控制对这个对象的访问

### 何时使用 ###

*  想在访问一个类时做一些控制

### 优点 ###

1.  职责清晰
2.  高扩展性
3.  智能化

### 实例 ###

1.  动态代理
    
        /**
         * @Author: create_By: chenxin
         * @Data:Created in 2018/8/28 10:18
         * @Version:
         * @Acton:  明星接口
         */
        public interface Star {
        
            void confer();              //面谈
            void signContract();        //签合同
            void bookTicket();          //订票
            void sing();                //唱歌
            void collectMoney();        //结尾款
        }
    
     
    
        /**
         * @Author: create_By: chenxin
         * @Data:Created in 2018/8/28 10:22
         * @Version:
         * @Acton:  明星本人
         */
        public class RealStar implements Star {
        
            @Override
            public void confer() {
                System.out.println("RealStar.confer()");
            }
        
            @Override
            public void signContract() {
                System.out.println("RealStar.signContract()");
            }
        
            @Override
            public void bookTicket() {
                System.out.println("RealStar.bookTicket()");
            }
        
            @Override
            public void sing() {
                System.out.println("RealStar(周杰伦本人).sing()");
            }
        
            @Override
            public void collectMoney() {
                System.out.println("RealStar.collectMoney()");
            }
        }
    
        /**
         * @Author: create_By: chenxin
         * @Data:Created in 2018/8/28 10:56
         * @Version:
         * @Acton:
         */
        public class StarHandler implements InvocationHandler {
        
            Star star;
        
            public StarHandler(Star star) {
                this.star = star;
            }
        
            @Override
            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                Object o = null;
                System.out.println("商谈");
                if(method.getName().equals("sing")){
                    o = method.invoke(star,args);
                }
                System.out.println("结款");
                return o;
            }
        }
    
        public static void test1(){
                Star realStar = new RealStar();
                Star proxyStar = new ProxyStar(realStar);
                proxyStar.confer();
                proxyStar.signContract();
                proxyStar.bookTicket();
                proxyStar.sing();
                proxyStar.collectMoney();
            }
    
     
2.  静态代理
    
        /**
         * @Author: create_By: chenxin
         * @Data:Created in 2018/8/28 10:18
         * @Version:
         * @Acton:  明星接口
         */
        public interface Star {
        
            void confer();              //面谈
            void signContract();        //签合同
            void bookTicket();          //订票
            void sing();                //唱歌
            void collectMoney();        //结尾款
        }
    
        /**
         * @Author: create_By: chenxin
         * @Data:Created in 2018/8/28 10:22
         * @Version:
         * @Acton:  明星本人
         */
        public class RealStar implements Star {
        
            @Override
            public void confer() {
                System.out.println("RealStar.confer()");
            }
        
            @Override
            public void signContract() {
                System.out.println("RealStar.signContract()");
            }
        
            @Override
            public void bookTicket() {
                System.out.println("RealStar.bookTicket()");
            }
        
            @Override
            public void sing() {
                System.out.println("RealStar(周杰伦本人).sing()");
            }
        
            @Override
            public void collectMoney() {
                System.out.println("RealStar.collectMoney()");
            }
        }
    
        /**
         * @Author: create_By: chenxin
         * @Data:Created in 2018/8/28 10:24
         * @Version:
         * @Acton:  代理人
         */
        public class ProxyStar  implements Star{
        
            private Star star;
        
            public ProxyStar(Star star) {
                this.star = star;
            }
        
            @Override
            public void confer() {
                System.out.println("ProxyStar.confer()");
            }
        
            @Override
            public void signContract() {
                System.out.println("ProxyStar.signContract()");
            }
        
            @Override
            public void bookTicket() {
                System.out.println("ProxyStar.bookTicket()");
            }
        
            @Override
            public void sing() {
                star.sing();
            }
        
            @Override
            public void collectMoney() {
                System.out.println("ProxyStar.collectMoney()");
            }
        }
    
        /* 测试静态代理 */
            public static void test2(){
                xin.chen.structural_type.proxy.dynamicProxy.Star realStar = new xin.chen.structural_type.proxy.dynamicProxy.RealStar();
                StarHandler handler = new StarHandler(realStar);
                xin.chen.structural_type.proxy.dynamicProxy.Star proxy = (xin.chen.structural_type.proxy.dynamicProxy.Star) Proxy.newProxyInstance(ClassLoader.getSystemClassLoader(), new Class[]{xin.chen.structural_type.proxy.dynamicProxy.Star.class}, handler);
                proxy.sing();
        
            }

### 关系图 ###

1.  静态代理  
    ![70][]
2.  动态代理  
    ![70 1][]

[70]: /images/20220511/f676a86329ab442db0fa62a7c72a1d3e.png
[70 1]: /images/20220511/c69f443ad1ce487caa05a25316a5d9ee.png