实验15：职责链模式

本次实验属于模仿型实验，通过本次实验学生将掌握以下内容： 

1、理解职责链模式的动机，掌握该模式的结构；

2、能够利用职责链模式解决实际问题。

[实验任务]：财务审批

某物资管理系统中物资采购需要分级审批，主任可以审批1万元及以下的采购单，部门经理可以审批5万元及以下的采购单，副总经理可以审批10万元及以下的采购单，总经理可以审批20万元及以下的采购单，20万元以上的采购单需要开职工大会确定。现用职责链模式设计该系统。

类图

 

源代码

public abstract class Leader
{protected String name;protected Leader successor;public Leader(String name){this.name = name;}public void setSuccessor(Leader successor){this.successor = successor;}public abstract void handleRequest(PurchaseRequest request);
}public class DepartmentManager extends Leader
{public DepartmentManager(String name){super(name);}@Overridepublic void handleRequest(PurchaseRequest request){if (request.getMoney() <= 50000){System.out.println("部门经理" + name + "审批采购单，采购单单号为：" + request.getId() + ",金额为：" + request.getMoney() + "元");} else{if (this.successor != null){this.successor.handleRequest(request);}}}
}public class Director extends Leader
{public Director(String name){super(name);}@Overridepublic void handleRequest(PurchaseRequest request){if (request.getMoney() <= 10000){System.out.println("主任" + name + "审批采购单，采购单单号为：" + request.getId() + ",金额为：" + request.getMoney() + "元");} else{if (this.successor != null){this.successor.handleRequest(request);}}}
}public class GeneralManager extends Leader
{public GeneralManager(String name){super(name);}@Overridepublic void handleRequest(PurchaseRequest request){if (request.getMoney() <= 200000){System.out.println("总经理" + name + "审批采购单，采购单单号为：" + request.getId() + ",金额为：" + request.getMoney() + "元");} else{System.out.println("采购单单号为：" + request.getId() + ",金额为：" +request.getMoney() + "元，金额太大，需开职工大会确定是否审批通过");}}
}public class Manager extends Leader
{public Manager(String name){super(name);}@Overridepublic void handleRequest(PurchaseRequest request){if (request.getMoney() <= 100000){System.out.println("副总经理" + name + "审批采购单，采购单单号为：" + request.getId() + ",金额为：" + request.getMoney() + "元");} else{if (this.successor != null){this.successor.handleRequest(request);}}}
}public class PurchaseRequest
{private int money;private int id;public PurchaseRequest(int id, int money){this.id = id;this.money = money;}public int getMoney(){return money;}public void setMoney(int money){this.money = money;}public int getId(){return id;}public void setId(int id){this.id = id;}
}public class Client
{public static void main(String[] args){Leader objDirector, objDepartmentManager, objManager, objGeneralManager;objDirector = new Director("张三");objDepartmentManager = new DepartmentManager("李四");objManager = new Manager("王五");objGeneralManager = new GeneralManager("赵六");objDirector.setSuccessor(objDepartmentManager);objDepartmentManager.setSuccessor(objManager);objManager.setSuccessor(objGeneralManager);PurchaseRequest pr1=new PurchaseRequest(1001,10000);objDirector.handleRequest(pr1);PurchaseRequest pr2=new PurchaseRequest(1002,50000);objDirector.handleRequest(pr2);PurchaseRequest pr3=new PurchaseRequest(1003,100000);objDirector.handleRequest(pr3);PurchaseRequest pr4=new PurchaseRequest(1004,200000);objDirector.handleRequest(pr4);PurchaseRequest pr5=new PurchaseRequest(1005,200001);objDirector.handleRequest(pr5);}
}

运行效果