设计模式08 桥接模式

桥接模式(Bridge)定义：将抽象与实现分离，使它们可以独立变化。它是用组合关系代替继承关系来实现，从而降低了抽象和实现这两个可变维度的耦合度。

如上图所示，平直的那条"聚合关系"就像一座桥一样。

实现部分：

 1 public interface Implementor {
 2     public void OperationImpl();
 3 }
 4 
 5 public class ConcreteImplementorA implements Implementor {
 6     @Override
 7     public void OperationImpl() {
 8         // TODO Auto-generated method stub
 9         System.out.println("形状：方形");
10     }
11 }
12 
13 public class ConcreteImplementorB implements Implementor {
14     @Override
15     public void OperationImpl() {
16         // TODO Auto-generated method stub
17         System.out.println("形状：圆形");
18     }
19 }

抽象部分：

 1 public abstract class Abstraction {
 2     protected Implementor implementor;
 3 
 4     protected Abstraction(Implementor implementor) {
 5         this.implementor = implementor;
 6     }
 7     
 8     public abstract void Operation();
 9 }
10 
11 public class RefinedAbstractionA extends Abstraction {
12     protected RefinedAbstractionA(Implementor implementor) {
13         super(implementor);
14         // TODO Auto-generated constructor stub
15     }
16 
17     @Override
18     public void Operation() {
19         // TODO Auto-generated method stub
20         System.out.println("颜色：红色");
21         implementor.OperationImpl();
22     }
23 }
24 
25 public class RefinedAbstractionB extends Abstraction {
26     protected RefinedAbstractionB(Implementor implementor) {
27         super(implementor);
28         // TODO Auto-generated constructor stub
29     }
30 
31     @Override
32     public void Operation() {
33         // TODO Auto-generated method stub
34         System.out.println("颜色：黄色");
35         implementor.OperationImpl();
36     }
37 }
38 
39 public class RefinedAbstractionC extends Abstraction {
40     protected RefinedAbstractionC(Implementor implementor) {
41         super(implementor);
42         // TODO Auto-generated constructor stub
43     }
44 
45     @Override
46     public void Operation() {
47         // TODO Auto-generated method stub
48         System.out.println("颜色：蓝色");
49         implementor.OperationImpl();
50     }
51 }

调用方式：

 1 public class Client {
 2     public static void main(String[] args) {
 3         //以这两个抽象类型(接口)声明的对象，是稳定的。根据其子类的不同，会有不同的表现。
 4         Implementor imple;
 5         Abstraction abs;
 6         
 7         //双重扩展点
 8         //方形+红色
 9         imple = new ConcreteImplementorA();//方形
10         abs = new RefinedAbstractionA(imple);//将"方形"送入"红色"
11         
12         ////圆形+蓝色
13         //imple = new ConcreteImplementorB();//圆形
14         //abs = new RefinedAbstractionC(imple);//将"圆形"送入"蓝色"
15                 
16         abs.Operation();
17     }
18 }

执行结果：

posted on 2019-12-28 11:06 Sempron2800+ 阅读(142) 评论(0) 编辑收藏举报