设计模式14-责任链模式

1. 概念

    使多个对象都有机会处理请求，从而避免请求的送发者和接收者之间的耦合关系  

2. 案例

  

package org.demo.chainofresponsibility.demo;
/**
 * 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收者之间的耦合关系。将这些对象连成一条链，
        并沿着这条链传递该请求，直到有一个对象处理它为止
 * Function : 
 * @author : Liaokailin
 * CreateDate : 2014-3-7
 * version : 1.0
 */

interface Request{
    void myRequest() ;
}

class DimissionRequest implements Request{

    @Override
    public void myRequest() {
        System.out.println("离职请求") ;
    }
}

class AddMoneyRequest implements Request{
    public void myRequest(){
        System.out.println("加薪请求") ;
    }
}

interface RequestHandler{
    public void handle(Request request) ;
}

class HRRequestHandler implements RequestHandler{
    @Override
    public void handle(Request request) {
        if(request instanceof DimissionRequest){
            System.out.println("人力资源审批中..") ;
        }
        System.out.println("人力资源审批结束") ;
    }
}

class PMRequestHandler implements RequestHandler{
    RequestHandler rh ; 
    public PMRequestHandler(RequestHandler rh){
        this.rh = rh ;
    }
    @Override
    public void handle(Request request) {
        boolean result = false ;
        if(request instanceof AddMoneyRequest){
            System.out.println("项目经理审批中...") ;
            result = true ;
        }
        if(result){ //转交到部门经理
            rh.handle(request) ;
        }
    }
    
}

class DMRequestHandler implements RequestHandler{
    /*RequestHandler rh  ;
    public DMRequestHandler(RequestHandler rh){
        this.rh = rh ;
    }*/
    @Override
    public void handle(Request request) {
        if(request instanceof AddMoneyRequest){
            System.out.println("部门经理审批中...") ;
        }
        System.out.println("部门经理审批结束 加薪一万块.") ;
    }
}
public class Demo01 {
    public static void main(String args[]){
        Request dimissionRequest = new DimissionRequest() ;
        RequestHandler rh01 = new HRRequestHandler() ;
        rh01.handle(dimissionRequest) ;
        
        Request addMoenyRequest = new AddMoneyRequest() ;
        RequestHandler rh02 = new PMRequestHandler(new DMRequestHandler()) ;
        rh02.handle(addMoenyRequest) ;
        
        
    }
}