职责链模式（responsibilitychain）

问题引入

一个人请假，根据请假天数的不同，应该由不同的人处理

模式引入

public abstract class Handle {
    

    Handle nextHandle;

    String name;

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

    /** * @Description: 设置下一个处理者，为了让子类形成链条 * @Param nextHandle: * @return void * @date 2022/7/31 10:44 */
    public void setNextHandle(Handle nextHandle) {
    
        this.nextHandle = nextHandle;
    }

    /** * @Description: 假期请求处理抽象方法，具体实现交给子类 * @Param vacationRequest: * @return void * @date 2022/7/31 10:46 */
    public abstract void processRequest(VacationRequest vacationRequest);

}

• 具体子类

public class GroupLeader extends Handle {
    

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

    @Override
    public void processRequest(VacationRequest vacationRequest) {
    
        if (vacationRequest.getVacationDay() <= 3) {
    
            System.out.println(vacationRequest.getId() + "被组长处理");
        } else {
     // 将请求传递给下一个执行链
            nextHandle.processRequest(vacationRequest);
        }
    }
}

• 具体子类

public class Manager extends Handle{
    

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

    @Override
    public void processRequest(VacationRequest vacationRequest) {
    
        if (vacationRequest.getVacationDay() > 3 && vacationRequest.getVacationDay() <= 30) {
    
            System.out.println(vacationRequest.getId() + "被经理处理了");
        } else {
    
            nextHandle.processRequest(vacationRequest);
        }
    }
}

• 具体子类

public class Chairman extends Handle {
    

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

    @Override
    public void processRequest(VacationRequest vacationRequest) {
    
        if (vacationRequest.getVacationDay() > 30) {
    
            System.out.println(vacationRequest.getId() + "被董事长处理了");
        } else {
    
            nextHandle.processRequest(vacationRequest);
        }
    }
}

• 封装一个请求类

public class VacationRequest {
    

    private int type = 0;

    private int vacationDay; // 请假天数

    private int id;

    public VacationRequest(int type, int vacationDay, int id) {
    
        this.type = type;
        this.vacationDay = vacationDay;
        this.id = id;
    }

    public int getType() {
    
        return type;
    }

    public int getVacationDay() {
    
        return vacationDay;
    }

    public int getId() {
    
        return id;
    }
}

调用测试

public class Client {
    

    public static void main(String[] args) {
    
        // 创建一个请求
        VacationRequest vacationRequest = new VacationRequest(1, 130, 1111);

        // 创建相关负责人
        GroupLeader groupLeader = new GroupLeader("组长");
        Manager manager = new Manager("经理");
        Chairman chairman = new Chairman("懂事长");

        // 设置链条,形成环路
        groupLeader.setNextHandle(manager);
        manager.setNextHandle(chairman);
        chairman.setNextHandle(groupLeader);

        groupLeader.processRequest(vacationRequest);

    }

}