设计模式之职责链模式实例（c++）

最新推荐文章于 2025-01-11 10:45:00 发布

Sincky丶

最新推荐文章于 2025-01-11 10:45:00 发布

阅读量540

点赞数

分类专栏：设计模式(c++) 文章标签：设计模式职责链模式 c++

本文链接：https://blog.youkuaiyun.com/lxq1997/article/details/90613117

版权

设计模式(c++) 专栏收录该内容

25 篇文章

订阅专栏

本文介绍了职责链模式的概念，通过一个审批假条的实例展示了如何在C++中应用该模式。文章详细阐述了如何创建请求类LeaveRequest，以及定义抽象处理者Leader接口和具体处理者Director、Manager、GeneralManager，它们沿职责链传递请求，由能处理的对象进行处理。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

职责链模式

职责链模式避免请求发送者与接收者耦合在一起，让多个对象都有可能接收请求，将这些对象连接成一条链，并且沿着这条链传递请求，直到有对象处理它为止。

职责链模式实例之审批假条

从类图可知，Direcor、Manager、GeneralManager泛化继承并实现了Leader的handleRequest接口，当具体处理者无法处理请求的时候，会传递给下家successor(上级)来处理，谁能处理就交给谁处理，不能处理就将请求传递给上级，从而形成一条职责链。

下面是c++版本的实现

请求类LeaveRequest

//请求类LeaveRequest
class LeaveRequest{
public:
	LeaveRequest(string leaveName,int leaveDays){
		this->leaveName = leaveName;
		this->leaveDays = leaveDays;
	}
	
	void setLeaveName(string leaveName){
		this->leaveName = leaveName;
	}
	
	void setLeaveDays(int leaveDays){
		this->leaveDays = leaveDays;
	}
	
	string getLeaveName() const{
		return this->leaveName;
	}
	
	int getLeaveDays() const{
		return this->leaveDays;
	}
private:
	string leaveName;
	int leaveDays;
};

抽象处理者Leader

//抽象处理者Leader
class Leader{
public:
	Leader(string name){
		this->name = name;
	}
	
	void setSuccessor(weak_ptr<Leader> successor){
		this->successor = successor;
	}
	
	virtual void handleRequest(const LeaveRequest &request) = 0;
	
protected:
	string name;
	weak_ptr<Leader> successor;
};

具体处理者Director

//具体处理者Director
class Director : public Leader{
public:
	Director(string name) : Leader(name){
		
	}
	
	void handleRequest(const LeaveRequest &request){
		//处理请求 
		if(request.getLeaveDays()<3){
			cout << "主任" << this->name << "审批员工" << request.getLeaveName() << "的请假条，请假天数为"
			 	 << request.getLeaveDays() << "天." << endl; 
		}else{
			//无法处理此请求，则交给上级处理 
			if(this->successor.lock()!=nullptr){
				this->successor.lock()->handleRequest(request);
			}
		}
	}
	
};

具体处理者Manager

//具体处理者Manager
class Manager : public Leader{
public:
	Manager(string name) : Leader(name){
		
	}
	
	void handleRequest(const LeaveRequest &request){
		//处理请求 
		if(request.getLeaveDays()<10){
			cout << "经理" << this->name << "审批员工" << request.getLeaveName() << "的请假条，请假天数为"
			 	 << request.getLeaveDays() << "天." << endl; 
		}else{
			//无法处理此请求，则交给上级处理 
			if(this->successor.lock()!=nullptr){
				this->successor.lock()->handleRequest(request);
			}
		}
	}
	
};

具体处理者GeneralManager

//具体处理者GeneralManager
class GeneralManager : public Leader{
public:
	GeneralManager(string name) : Leader(name){
		
	}
	
	void handleRequest(const LeaveRequest &request){
		//处理请求 
		if(request.getLeaveDays()<30){
			cout << "总经理" << this->name << "审批员工" << request.getLeaveName() << "的请假条，请假天数为"
			 	 << request.getLeaveDays() << "天." << endl; 
		}else{
			cout << "莫非" << request.getLeaveName() << "想辞职,居然请假" 
			 	 << request.getLeaveDays() << "天." << endl; 
		}
	}
	
};

客户端测试

//客户端测试 
int main(void){
	shared_ptr<Leader> objDirector,objManager,objGeneralManager;
	
	//创建处理者
	objDirector = make_shared<Director>("王明");
	objManager = make_shared<Manager>("赵强");
	objGeneralManager = make_shared<GeneralManager>("李波");
	
	//设置上级
	objDirector->setSuccessor(objManager);
	objManager->setSuccessor(objGeneralManager);
	
	//职责链处理请求
	shared_ptr<LeaveRequest> lr1 = make_shared<LeaveRequest>("张三",2);
	objDirector->handleRequest(*lr1);
	
	shared_ptr<LeaveRequest> lr2 = make_shared<LeaveRequest>("李四",5);
	objDirector->handleRequest(*lr2);
	
	shared_ptr<LeaveRequest> lr3 = make_shared<LeaveRequest>("王五",15);
	objDirector->handleRequest(*lr3);
	
	shared_ptr<LeaveRequest> lr4 = make_shared<LeaveRequest>("赵六",45);
	objDirector->handleRequest(*lr4);
	
	return 0;
}

输出结果