职责链模式ChainOfResponsibility

  职责链模式（ChainOfResponsibility）：使多个对象都有机会处理请求，从而避免请求的
发送者和接受者之间的耦合关系。将这个对象连成一条链，并沿着这条链传递该请求，直到
有一个对象处理它为止。

 下面是类结构图：

 

  Handler.java

  package com.china_chenglong; public abstract class Handler { protected Handler successor; public void SetSuccessor(Handler successor){ this.successor = successor; } public abstract void HandlerRequest(int request); }

 

  ConcreateHandler1.java

  package com.china_chenglong; public class ConcreteHandler1 extends Handler { public void HandlerRequest(int request) { if(request >=0 && request <10){ System.out.println("ConcreteHandler1处理请求"+request); } else if(successor!=null){ successor.HandlerRequest(request); } } } 

 

  ConcreteHandler2.java

  package com.china_chenglong; public class ConcreteHandler2 extends Handler { public void HandlerRequest(int request) { if(request>=10 && request<20){ System.out.println("ConcreteHandler2处理请求"+request); } else if(successor!=null){ successor.HandlerRequest(request); } } } 

 

  ConcreteHandler3.java

  package com.china_chenglong; public class ConcreteHandler3 extends Handler { public void HandlerRequest(int request) { if(request>=20 && request<30){ System.out.println("ConcreteHandler3处理请求"+request); } else if(successor!=null){ successor.HandlerRequest(request); } } } 

 

  Main.java

  package com.china_chenglong; public class Main { public static void main(String[] args) { Handler h1 = new ConcreteHandler1(); Handler h2 = new ConcreteHandler2(); Handler h3 = new ConcreteHandler3(); //设置职责链 h1.SetSuccessor(h2); h2.SetSuccessor(h3); int[] requests={2,5,14,22,18,3,27,20}; for(int i =0;i<requests.length;i++){ h1.HandlerRequest(requests[i]); } } }