15.职责链模式

[实验任务一]：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

代码

java代码

package test15;

public class AllStaff extends Leader{
    public AllStaff(String name) {
        super(name);
    }

    @Override
    public void handleRequest(GoodsBuy buy) {
        if (buy.getYuan()>20){
            System.out.println("召开职工大会确定采购"+buy.getYuan()+"万元的采购单");
        }
    }
}

package test15;

public class Client {

    public static void main(String[] args) {
        Leader a1,a2,a3,a4,a5;
        a1 = new Director("a1");
        a2 = new DepartmentManager("a2");
        a3 = new FuManager("a3");
        a4 = new ZongManager("a4");
        a5 = new AllStaff("a5");

        a1.setSuccessor(a2);
        a2.setSuccessor(a3);
        a3.setSuccessor(a4);
        a4.setSuccessor(a5);

        GoodsBuy goodsBuy = new GoodsBuy(12);

        a1.handleRequest(goodsBuy);
    }

}

package test15;

public class DepartmentManager extends Leader{

    public DepartmentManager(String name) {
        super(name);
    }

    @Override
    public void handleRequest(GoodsBuy buy) {
        if(buy.getYuan()<5){
            System.out.println("部门经理"+name+"审批"+buy.getYuan()+"万元的采购单");
        }else {
            if(this.successor!=null){
                this.successor.handleRequest(buy);
            }
        }
    }
}

package test15;

public class Director extends Leader{

    public Director(String name) {
        super(name);
    }

    @Override
    public void handleRequest(GoodsBuy buy) {
        if(buy.getYuan()<1){
            System.out.println("主任"+name+"审批"+buy.getYuan()+"万元的采购单");
        }else {
            if(this.successor!=null){
                this.successor.handleRequest(buy);
            }
        }
    }
}

package test15;

public class FuManager extends Leader{
    public FuManager(String name) {
        super(name);
    }

    @Override
    public void handleRequest(GoodsBuy buy) {
        if (buy.getYuan()<10){
            System.out.println("副总经理"+name+"审批"+buy.getYuan()+"万元的订单");
        }else {
            if (this.successor!=null){
                this.successor.handleRequest(buy);
            }
        }
    }
}

package test15;

public class GoodsBuy {

    private int yuan;

    public GoodsBuy(int yuan){
        this.yuan = yuan;
    }

    public void setYuan(int yuan) {
        this.yuan = yuan;
    }

    public int getYuan() {
        return yuan;
    }
}

package test15;

public abstract class Leader {

    protected String name;
    /*
    ==关键类==
    这个Leader就像C++中的指针一样
     */
    protected Leader successor;

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

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

    public abstract void handleRequest(GoodsBuy buy);
}

package test15;

public class ZongManager extends Leader{
    public ZongManager(String name) {
        super(name);
    }

    @Override
    public void handleRequest(GoodsBuy buy) {
        if (buy.getYuan()<20){
            System.out.println("总经理"+name+"审批"+buy.getYuan()+"万元的采购单");
        }else {
            if (this.successor!=null){
                successor.handleRequest(buy);
            }
        }
    }
}

c++代码

#include <iostream>
using namespace std;

class GoodsBuy{
private:
    int yuan;
public:
    GoodsBuy(int yuan){ this->yuan = yuan;}
    int getYuan(){return this->yuan;}
};

class Leader{
protected:
    string name;
    Leader* leader;
public:
    Leader(string name){
        this->name = name;
    }
    void setSuccessor(Leader* leader){
        this->leader = leader;
    }
    virtual void handleRequest(GoodsBuy goodsBuy){}
};

class DepartmentManager:public Leader{
public:
    DepartmentManager(string name):Leader(name){}
    void handleRequest(GoodsBuy goodsBuy){
        if(goodsBuy.getYuan()<5){
            cout<<"部门经理"+name+"审批";
            cout<<goodsBuy.getYuan();
            cout<<"万元的采购单";
        } else{
            leader->handleRequest(goodsBuy);
        }
    }
};

class Director:public Leader{
public:
    Director(string name):Leader(name){}
    void handleRequest(GoodsBuy goodsBuy){
        if(goodsBuy.getYuan()<1){
            cout<<"主任"+name+"审批";
            cout<<goodsBuy.getYuan();
            cout<<"万元的采购单";
        } else{
            leader->handleRequest(goodsBuy);
        }
    }
};

class FuManager:public Leader{
public:
    FuManager(string name):Leader(name){}
    void handleRequest(GoodsBuy goodsBuy){
        if(goodsBuy.getYuan()<10){
            cout<<"主任"+name+"审批";
            cout<<goodsBuy.getYuan();
            cout<<"万元的采购单";
        } else{
            leader->handleRequest(goodsBuy);
        }
    }
};

class ZongManager:public Leader{
public:
    ZongManager(string name):Leader(name){}
    void handleRequest(GoodsBuy goodsBuy){
        if(goodsBuy.getYuan()<20){
            cout<<"总经理"+name+"审批";
            cout<<goodsBuy.getYuan();
            cout<<"万元的采购单";
        } else{
            leader->handleRequest(goodsBuy);
        }
    }
};

class AllStaff: public Leader{
public:
    AllStaff(string name):Leader(name){}
    void handleRequest(GoodsBuy goodsBuy){
        if(goodsBuy.getYuan()>20){
            cout<<"召开职工大会确定采购";
            cout<<goodsBuy.getYuan();
            cout<<"万元的采购单";
        } else{
            leader->handleRequest(goodsBuy);
        }
    }
};

int main(){
    Director a1("a1");
    DepartmentManager a2("a2");
    FuManager a3("a3");
    ZongManager a4("a4");
    AllStaff a5("a5");

    a1.setSuccessor(&a2);
    a2.setSuccessor(&a3);
    a3.setSuccessor(&a4);
    a4.setSuccessor(&a5);

    GoodsBuy goodsBuy(12);

    a1.handleRequest(goodsBuy);
}