装饰者模式--Java篇
装饰者模式(Decorator):动态地给一个对象添加一些额外的职责,就增加功能来说,装饰者模式比生成子类更为灵活。
1.定义接口,可以动态的给对象添加职责。
1 package com.lujie; 2 3 public interface SuperPerson { 4 //定义一个接口,可以动态的给对象添加职责 5 public abstract void show() ; 6 }
2.实现这个接口
1 package com.lujie; 2 3 public class Person implements SuperPerson{ 4 private String name; 5 public Person() { 6 // TODO Auto-generated constructor stub 7 } 8 public Person(String name) { 9 this.name=name; 10 } 11 //具体对象的操作 12 public void show() { 13 System.out.println("装饰者:"+name); 14 } 15 }
3.装饰类
1 package com.lujie; 2 3 public class Finery extends Person{ 4 protected Person component; 5 //设置component 6 public void Decorate(Person component) { 7 this.component=component; 8 } 9 //重写show(),实际执行的是component的show()操作 10 public void show() { 11 if(component!=null){ 12 component.show(); 13 } 14 } 15 16 }
4.具体实现的装饰类
1 package com.lujie; 2 3 public class Shoes extends Finery{ 4 //首先执行本类的功能,再运行原Component的show(),相当于对原Component进行了装饰 5 public void show() { 6 System.out.println("皮鞋"); 7 super.show(); 8 } 9 }
1 package com.lujie; 2 3 public class Suit extends Finery{ 4 //首先执行本类的功能,再运行原Component的show(),相当于对原Component进行了装饰 5 public void show() { 6 System.out.println("西装"); 7 super.show(); 8 } 9 }
package com.lujie; //具体服饰类 public class TShirts extends Finery{ //首先执行本类的功能,再运行原Component的show(),相当于对原Component进行了装饰 public void show() { System.out.println("大体恤"); super.show(); } }
1 package com.lujie; 2 3 public class WearSneakers extends Finery{ 4 public void show() { 5 System.out.println("破球鞋"); 6 super.show(); 7 } 8 }
5.测试用例:
1 package com.lujie; 2 3 public class PersonShowMain { 4 5 public static void main(String[] args) { 6 // TODO Auto-generated method stub 7 Person person=new Person("小明"); 8 System.out.println("第一种装扮:"); 9 WearSneakers wSneakers=new WearSneakers(); 10 BigTrouser bigTrouser=new BigTrouser(); 11 TShirts tShirts=new TShirts(); 12 //装饰过程 13 wSneakers.Decorate(person); 14 bigTrouser.Decorate(wSneakers); 15 tShirts.Decorate(bigTrouser); 16 tShirts.show(); 17 //装饰过程二 18 System.out.println("第二种装扮:"); 19 Suit suit=new Suit(); 20 wSneakers.Decorate(person); 21 bigTrouser.Decorate(wSneakers); 22 suit.Decorate(bigTrouser); 23 suit.show(); 24 } 25 26 }
6.运行结果: