软件设计职责链模式

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

java

package rjsj.no15;

public abstract class Leader {
    protected String name;

    //上级领导
    protected Leader successor;

    public Leader(String name) {
        this.name = name;
    }

    public void setSuccessor(Leader successor) {
        this.successor = successor;
    }

    protected abstract void handleRequest(ShoppingRequest request);
}

package rjsj.no15;

public class ShoppingRequest {
    private String shoppingReason;
    private double billMoney;

    public ShoppingRequest(String shoppingReason,double billMoney){
        this.shoppingReason = shoppingReason;
        this.billMoney = billMoney;
    }

    public String getShoppingReason() {
        return shoppingReason;
    }

    public void setShoppingReason(String shoppingReason) {
        this.shoppingReason = shoppingReason;
    }

    public double getBillMoney() {
        return billMoney;
    }

    public void setBillMoney(double billMoney) {
        this.billMoney = billMoney;
    }
}

package rjsj.no15;

public class Client {
    public static void main(String[] args) {
        Leader objDirector,objDepartmentManager,objViceManager,objGeneralManager;
        objDirector = new Director("张主任");
        objDepartmentManager = new DepartmentManager("刘部门经理");
        objViceManager = new ViceManager("王副经理");
        objGeneralManager = new GeneralManager("赵经理");

        //设置上级
        objDirector.setSuccessor(objDepartmentManager);
        objDepartmentManager.setSuccessor(objViceManager);
        objViceManager.setSuccessor(objGeneralManager);

        ShoppingRequest shoppingRequest1 = new ShoppingRequest("买打印纸",1000);
        ShoppingRequest shoppingRequest2 = new ShoppingRequest("购置电脑",20000);
        ShoppingRequest shoppingRequest3 = new ShoppingRequest("购置空调",80000);
        ShoppingRequest shoppingRequest4 = new ShoppingRequest("办公室装修",160000);
        ShoppingRequest shoppingRequest5 = new ShoppingRequest("收购XX公司",1000000);

        objDirector.handleRequest(shoppingRequest1);
        System.out.println("****************************************");
        objDirector.handleRequest(shoppingRequest2);
        System.out.println("****************************************");
        objDirector.handleRequest(shoppingRequest3);
        System.out.println("****************************************");
        objDirector.handleRequest(shoppingRequest4);
        System.out.println("****************************************");
        objDirector.handleRequest(shoppingRequest5);
        System.out.println("****************************************");
    }
}

package rjsj.no15;

//主任
class Director extends Leader{
    public Director(String name) {
        super(name);
    }

    public void handleRequest(ShoppingRequest request){
        if (request.getBillMoney()<10000.00){
            System.out.println(name + "主任处理物资采购" + request.getShoppingReason() + "采购资金为" + request.getBillMoney() + "元");
        } else {
            if (this.successor != null){
                this.successor.handleRequest(request);
            }
        }
    }
}

//部门经理
class DepartmentManager extends Leader{
    public DepartmentManager(String name) {
        super(name);
    }

    protected void handleRequest(ShoppingRequest request) {
        if (request.getBillMoney()<50000.00){
            System.out.println(name + "部门经理处理物资采购" + request.getShoppingReason() + "采购资金为" + request.getBillMoney() + "元");
        } else {
            if (this.successor != null){
                this.successor.handleRequest(request);
            }
        }
    }
}

//副经理
class ViceManager extends Leader{
    public ViceManager(String name) {
        super(name);
    }

    @Override
    protected void handleRequest(ShoppingRequest request) {
        if (request.getBillMoney()<100000.00){
            System.out.println(name + "副经理处理物资采购" + request.getShoppingReason() + "采购资金为" + request.getBillMoney() + "元");
        } else {
            if (this.successor != null){
                this.successor.handleRequest(request);
            }
        }
    }
}

//总经理
class GeneralManager extends Leader{
    public GeneralManager(String name) {
        super(name);
    }

    @Override
    protected void handleRequest(ShoppingRequest request) {
        if (request.getBillMoney()<200000.00){
            System.out.println(name + "总经理处理物资采购" + request.getShoppingReason() + "采购资金为" + request.getBillMoney() + "元");
        } else {
            System.out.println("董事会将开会处理物资采购" + request.getShoppingReason() + "采购资金为" + request.getBillMoney() + "元");
        }
    }
}

C++

#include<iostream>
using namespace std;
class PurchaseRequest {
private:
    int money;
public:
    PurchaseRequest(int money) {
        this->money=money;
    }
    void setMoney(int money) {
        this->money=money;
    }
    int getMoney(){
        return this->money;
    }
};
class Leader {
protected:
    string name;
    Leader *successor;
public:
    Leader(string name) {
        this->name=name;
    }
    void setSuccessor(Leader *successor) {
        this->successor=successor;
    }
    virtual void handleRequest(PurchaseRequest *request)=0;
};
class Director:public Leader{
private:
    string name;
public:
    Director(string name):Leader(name){}
    void handleRequest(PurchaseRequest *request) {
        // TODO Auto-generated method stub
        if(request->getMoney()<=1) {
            cout<<"主任"<<this->name<<"审批"<<request->getMoney()<<"万元的采购单"<<endl;
        }
        else {
            if(this->successor!=NULL) {
                this->successor->handleRequest(request);
            }
        }
    }
};
class Manager : public Leader{
private:
    string name;
public:
    Manager(string name):Leader(name){}
    void handleRequest(PurchaseRequest *request) {
        if(request->getMoney()<=5) {
            cout<<"部门经理"<<name<<"审批"<<request->getMoney()<<"万元的采购单"<<endl;
        }
        else {
            if(this->successor!=NULL) {
                this->successor->handleRequest(request);
            }
        }
    }
};
class DeputyGeneralManager: public Leader{
private:
    string name;
public:
    DeputyGeneralManager(string name):Leader(name){}
    void handleRequest(PurchaseRequest *request) {
        if(request->getMoney()<=10) {
            cout<<"副总经理"<<name<<"审批"<<request->getMoney()<<"万元的采购单"<<endl;
        }
        else {
            if(this->successor!=NULL) {
                this->successor->handleRequest(request);
            }
        }
    }
};
class GeneralManager: public Leader{
private:
    string name;
public:
    GeneralManager(string name):Leader(name){}
    void handleRequest(PurchaseRequest *request) {
        if(request->getMoney()<=20) {
            cout<<"总经理"<<name<<"审批"<<request->getMoney()<<"万元的采购单"<<endl;
        }
        else if(request->getMoney()>20) {
            cout<<"总经理"<<name<<"召开职工大会审批"<<request->getMoney()<<"万元的采购单"<<endl;
        }
        else {
            if(this->successor!=NULL) {
                this->successor->handleRequest(request);
            }
        }
    }
};
int main(){
        Leader *objDirector,*objManager,*objDeputyGeneralManager,*objGeneralManager;

        objDirector=new Director("张三");
        objManager=new Manager("李四");
        objDeputyGeneralManager=new DeputyGeneralManager("王五");
        objGeneralManager=new GeneralManager("赵六");

        objDirector->setSuccessor(objManager);
        objManager->setSuccessor(objDeputyGeneralManager);
        objDeputyGeneralManager->setSuccessor(objGeneralManager);

        PurchaseRequest *pr1=new PurchaseRequest(1);
        objDirector->handleRequest(pr1);
        PurchaseRequest *pr2=new PurchaseRequest(3);
        objDirector->handleRequest(pr2);
        PurchaseRequest *pr3=new PurchaseRequest(8);
        objDirector->handleRequest(pr3);
        PurchaseRequest *pr4=new PurchaseRequest(12);
        objDirector->handleRequest(pr4);
        PurchaseRequest *pr5=new PurchaseRequest(22);
        objDirector->handleRequest(pr5);
    return 0;
}

运行结果