责任链模式

Posted on | In |

责任链模式要达到的目的：责任链模式是一种对象的行为模式。在责任链模式里，很多对象由每一个对象对其下家的引用而连接起来形成一条链。请求在这个链上传递，直到链上的某一个对象决定处理此请求

具体实例


Application
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package zherenlian;

/**
 * Created by 15581 on 2017/11/8.
 */ // Application.java
public class Application{
    private Handler beijing,shanghai,tianjin;    //责任链上的对象
    public void createChain(){       //建立责任链
       beijing=new Beijing();
       shanghai=new Shanghai();
       tianjin=new Tianjin();
       beijing.setNextHandler(shanghai);
       shanghai.setNextHandler(tianjin);
    }
    public void reponseClient(String number){  //响应用户的请求
       beijing.handleRequest(number);
    }
    public static void main(String args[]){
       Application  application=new  Application();
       application.createChain();
       application.reponseClient("77720810340930632");;
    }
}

Beijing

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package zherenlian;

import java.util.ArrayList;

/**
 * Created by 15581 on 2017/11/8.
 */
public class Beijing implements Handler{
     private Handler handler;      //存放当前处理者后继的Hander接口变量
     private ArrayList<String> numberList; //存放身份证号码的数组线性表
     Beijing(){
        numberList=new ArrayList<String>();
        numberList.add("11129812340930034"); //这里使用模拟的身份证号码
        numberList.add("10120810340930632");
        numberList.add("22029812340930034");
        numberList.add("32620810340930632");
     }
     public void handleRequest(String number){
        if(numberList.contains(number))
           System.out.println("该人在北京居住");
        else{
           System.out.println("该人不在北京居住");
           if(handler!=null)
             handler.handleRequest(number);      //将请求传递给下一个处理者
        }
     }
     public void setNextHandler(Handler handler){
        this.handler=handler;
     }
}

Handler

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package zherenlian;

// Handler.java
public interface Handler{
   public abstract void handleRequest(String number);
   public abstract void setNextHandler(Handler handler);
}

Shanghai

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package zherenlian;

import java.util.ArrayList;

/**
 * Created by 15581 on 2017/11/8.
 */
public class Shanghai implements Handler{
     private Handler handler;              //存放当前处理者后继的Hander接口变量
     private ArrayList<String> numberList; //存放身份证号码的数组线性表
     Shanghai(){
        numberList=new ArrayList<String>();
        numberList.add("34529812340930034"); //这里使用模拟的身份证号码
        numberList.add("98720810340430632");
        numberList.add("36529812340930034");
        numberList.add("77720810340930632");
     }
     public void handleRequest(String number){
        if(numberList.contains(number))
           System.out.println("该人在上海居住");
        else{
           System.out.println("该人不在上海居住");
           if(handler!=null)
              handler.handleRequest(number);      //将请求传递给下一个处理者
        }
     }
     public void setNextHandler(Handler handler){
        this.handler=handler;
     }
}

Tianjin

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package zherenlian;

import java.util.ArrayList;

/**
 * Created by 15581 on 2017/11/8.
 */
public class Tianjin implements Handler{
     private Handler handler;              //存放当前处理者后继的Hander接口变量
     private ArrayList<String> numberList; //存放身份证号码的数组线性表
     Tianjin(){
        numberList=new ArrayList<String>();
        numberList.add("10029812340930034"); //这里使用模拟的身份证号码
        numberList.add("20020810340430632");
        numberList.add("30029812340930034");
        numberList.add("50020810340930632");
     }
     public void handleRequest(String number){
        if(numberList.contains(number))
           System.out.println("该人在天津居住");
        else{
           System.out.println("该人不在天津居住");
           if(handler!=null)
              handler.handleRequest(number);      //将请求传递给下一个处理者
        }
     }
     public void setNextHandler(Handler handler){
        this.handler=handler;
     }
}