设计模式——职责链模式

一、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。

二、类图

 

三、代码

1、Java代码

package tutorial15;


import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Scanner;
 
public class Client {
    public static void main(String args[]) {
        Leader director = new Director("Tom"),
        partmentManager = new PartmentManager("Jack"),
        generalManager = new GeneralManager("Rose"),
        vic = new VicManager("Wang");
 
        director.setSuccessor(partmentManager);
        partmentManager.setSuccessor(generalManager);
        generalManager.setSuccessor(vic);
        System.out.println("请输入要采购的金额：");
        Scanner in =new Scanner(System.in);
        int m=in.nextInt();
 
        Request request=new Request(new BigDecimal(m));
        
        director.handlerRequest(request);
        
        System.out.println("请输入要采购的金额：");
        int n=in.nextInt();
        Request request1=new Request(new BigDecimal(n));
        
        director.handlerRequest(request1);
       
        
    }
}

package tutorial15;

import java.math.BigDecimal;



abstract public class Leader {
    protected String name;
    protected Leader successor;
 
    public void setSuccessor(Leader successor){
        this.successor=successor;
    }
 
    public  Leader(String name){
        this.name=name;
    }
    abstract public void handlerRequest(Request request);


}

package tutorial15;

import java.math.BigDecimal;



public class Director extends Leader {
    public Director(String name){
        super(name);
    }
    public void handlerRequest(Request request){
       BigDecimal bigDecimal=new BigDecimal(10000.00);
        if(request.getCost().compareTo(bigDecimal)==-1||request.getCost().compareTo(bigDecimal)==0){
            System.out.println("主任"+name+"审批，采购金额为："+request.getCost());
        }
        else {
            this.successor.handlerRequest(request);
        }
    }



}

package tutorial15;

import java.math.BigDecimal;

//副总经理
public class GeneralManager extends Leader{
    public GeneralManager(String name){
        super(name);
    }
    public void handlerRequest(Request request){
        BigDecimal bigDecimal=new BigDecimal(100000.00);
        if(request.getCost().compareTo(bigDecimal)==-1||request.getCost().compareTo(bigDecimal)==0){
            System.out.println("副总经理"+name+"审批，采购金额为："+request.getCost());
        }
        else {
            this.successor.handlerRequest(request);
        }
    }



}

package tutorial15;

import java.math.BigDecimal;

//部门经理
public class PartmentManager extends Leader{
    public PartmentManager(String name){
        super(name);
    }
    public void handlerRequest(Request request){
        BigDecimal bigDecimal=new BigDecimal(50000.00);
        if(request.getCost().compareTo(bigDecimal)==-1||request.getCost().compareTo(bigDecimal)==0){
            System.out.println("部门经理"+name+"审批，采购金额为："+request.getCost());
        }
        else {
            this.successor.handlerRequest(request);
        }
    }


}

package tutorial15;

import java.math.BigDecimal;

//总经理
public class VicManager extends Leader{
    public VicManager(String name){
        super(name);
    }
    public void handlerRequest(Request request){
        BigDecimal bigDecimal=new BigDecimal(200000.00);
        if(request.getCost().compareTo(bigDecimal)==-1||request.getCost().compareTo(bigDecimal)==0){
            System.out.println("总经理"+name+"审批，采购金额为："+request.getCost());
        }
        else {
            System.out.println("采购金额为："+request.getCost()+"   "+"数额过大，需开会决定！");
        }
    }


}

package tutorial15;

import java.math.BigDecimal;

public class Request {
     private BigDecimal cost;
        public Request(BigDecimal bigDecimal){
            this.cost=bigDecimal;
        }
        public BigDecimal getCost(){
            return cost;
        }
        public void setCost(BigDecimal bigDecimal){
            this.cost=bigDecimal;
        }


}

2、C++代码

#include<iostream>
using namespace std;
//抽象管理者
class Manager
{
protected:
    Manager* m_manager;
    string m_name;
public:
    Manager(Manager* manager, string name) :m_manager(manager), m_name(name) {}
    virtual void DealWithRequest(string name, int num) {}
};
//部门经理
class Director : public Manager
{
public:
    Director(Manager* manager, string name) :Manager(manager, name) {}

    void DealWithRequest(string name, int num)
    {
        if (num < 10000) //经理职权之内
        {
            cout << "主任" << m_name << "审批" << name << "采购金额：" << num << "元" << endl << endl;
        }
        else
        {
            cout << "主任" << m_name << "无法处理，交由部门经理处理" << endl;
            m_manager->DealWithRequest(name, num);
        }
    }
};
//部门经理
class DepartmentManager : public Manager
{
public:
    DepartmentManager(Manager* manager, string name) :Manager(manager, name) {}
    void DealWithRequest(string name, int num)
    {
        if (num < 50000) //经理职权之内
        {
            cout << "部门经理" << m_name << "审批" << name << "采购金额：" << num << "元" << endl << endl;
        }
        else
        {
            cout << "部门经理" << m_name << "无法处理，交由副总经理处理" << endl;
            m_manager->DealWithRequest(name, num);
        }
    }
};
//副总经理
class DeputyManager : public Manager
{
public:
    DeputyManager(Manager* manager, string name) :Manager(manager, name) {}
    void DealWithRequest(string name, int num)
    {
        if (num < 100000) //总监职权之内
        {
            cout << "副总经理" << m_name << "审批" << name << "采购金额：" << num << "元" << endl << endl;
        }
        else
        {
            cout << "副总经理" << m_name << "无法处理，交由总经理处理" << endl;
            m_manager->DealWithRequest(name, num);
        }
    }
};
//总经理
class GeneralManager : public Manager
{
public:
    GeneralManager(Manager* manager, string name) :Manager(manager, name) {}
    void DealWithRequest(string name, int num)  //总经理可以处理所有请求
    {
        if (num < 200000) {
            cout << "副总经理" << m_name << "审批" << name << "采购金额：" << num << "元" << endl << endl;
        }
        else {
            cout << "采购金额为：" << num << "元，采购金额过大，需开职工大会决定！" << endl;
        }
    }
};
int main()
{
    Manager* general = new GeneralManager(NULL, "A"); //设置上级，总经理没有上级
    Manager* deputyManager = new DeputyManager(general, "B"); //设置副总经理上级为总经理
    Manager* departmentManager = new DepartmentManager(deputyManager, "C"); //设置部门经理上级为副总经理
    Manager* director = new Director(departmentManager, "D"); //设置部门经理上级为副总经理
    cout << "请输入采购金额：";
    int m;
    cin >> m;
    director->DealWithRequest("采购员", m);


    delete director;
    delete departmentManager; 
    delete deputyManager;
    delete general;
    return 0;
}

四、结果

1、Java结果截图：

 

2、C++结果截图：