二哈谈设计模式之责任链模式

编程入门行业动态更新时间:2024-10-11 05:20:02

二哈谈设计<a href=https://www.elefans.com/category/jswz/34/1771241.html style= 模式之责任链模式"/>

二哈谈设计模式之责任链模式

责任链模式

文章目录

责任链模式
前言
一、具体实现
- 1.实体类（请假信息）
- 2.抽象处理者角色
- 3.具体处理者角色
- 4.测试类
二、应用场景
总结

前言

定义
将能够处理同一类请求的对象连成一条链，所提交的请求沿着链传递，链上的对象逐个判断是否有能力处理该请求，如果能则处理，如果不能则传递给链上的下一个对象。
场景
– 打牌时，轮流出牌
– 接力赛跑
– 大学中，奖学金审批
– 公司中，公文审批

案例:
在公司中，请假的审批流程为︰
如果请假天数小于3天，主任审批
如果请假天数大于等于3天，小于10天，经理审批
大于等于10天，小于20天的请假，副总经理审批如果大于等于20天，小于30天，总经理审批⑤如果大于等于30天，提示拒绝

一、具体实现

1.实体类（请假信息）

/*** 封装请假的基本信息* @author Administrator**/
public class LeaveRequest {private String empName;private int leaveDays;private String reason;public LeaveRequest(String empName, int leaveDays, String reason) {super();this.empName = empName;this.leaveDays = leaveDays;this.reason = reason;}public String getEmpName() {return empName;}public void setEmpName(String empName) {this.empName = empName;}public int getLeaveDays() {return leaveDays;}public void setLeaveDays(int leaveDays) {this.leaveDays = leaveDays;}public String getReason() {return reason;}public void setReason(String reason) {this.reason = reason;} }

2.抽象处理者角色

/*** 抽象类* @author Administrator**/
public abstract class Leader {protected String name;protected Leader nextLeader; //责任链上的后继对象public Leader(String name) {super();this.name = name;}//设定责任链上的后继对象public void setNextLeader(Leader nextLeader) {this.nextLeader = nextLeader;}/*** 处理请求的核心的业务方法* @param request*/public abstract void handleRequest(LeaveRequest request);}

3.具体处理者角色

package chainOfResponsibility;/*** 主任* @author Administrator**/
public class Director extends Leader {public Director(String name) {super(name);}@Overridepublic void handleRequest(LeaveRequest request) {if(request.getLeaveDays()<3){System.out.println("员工："+request.getEmpName()+"请假，天数："+request.getLeaveDays()+",理由："+request.getReason());System.out.println("主任："+this.name+",审批通过！");}else{if(this.nextLeader!=null){this.nextLeader.handleRequest(request);}}}}

package chainOfResponsibility;/*** 经理* @author Administrator**/
public class Manager extends Leader {public Manager(String name) {super(name);}@Overridepublic void handleRequest(LeaveRequest request) {if(request.getLeaveDays()<10){System.out.println("员工："+request.getEmpName()+"请假，天数："+request.getLeaveDays()+",理由："+request.getReason());System.out.println("经理："+this.name+",审批通过！");}else{if(this.nextLeader!=null){this.nextLeader.handleRequest(request);}}}}

package chainOfResponsibility;/*** 副总经理* @author Administrator**/
public class ViceGeneralManager extends Leader {public ViceGeneralManager(String name) {super(name);}@Overridepublic void handleRequest(LeaveRequest request) {if(request.getLeaveDays()<20){System.out.println("员工："+request.getEmpName()+"请假，天数："+request.getLeaveDays()+",理由："+request.getReason());System.out.println("副总经理："+this.name+",审批通过！");}else{if(this.nextLeader!=null){this.nextLeader.handleRequest(request);}}}}

package chainOfResponsibility;/*** 总经理* @author Administrator**/
public class GeneralManager extends Leader {public GeneralManager(String name) {super(name);}@Overridepublic void handleRequest(LeaveRequest request) {if(request.getLeaveDays()<30){System.out.println("员工："+request.getEmpName()+"请假，天数："+request.getLeaveDays()+",理由："+request.getReason());System.out.println("总经理："+this.name+",审批通过！");}else{System.out.println("莫非"+request.getEmpName()+"想辞职，居然请假"+request.getLeaveDays()+"天！");}}}

4.测试类

package chainOfResponsibility;public class Client {public static void main(String[] args) {Leader a = new Director("张三");Leader b = new Manager("李四");Leader b2 = new ViceGeneralManager("李小四");Leader c = new GeneralManager("王五");//组织责任链对象的关系a.setNextLeader(b);b.setNextLeader(b2);b2.setNextLeader(c);//开始请假操作LeaveRequest req1 = new LeaveRequest("TOM", 15, "回英国老家探亲！");a.handleRequest(req1);}
}

结果：