责任链模式

什么是责任链模式？

每个对象以链的方式进行连接，上级对象关联下级对象，一级一级的向下运行，直到运行到最后一个对象结束。

示例场景描述

某公司普通职员请假，申请请假后需要通过组长审批 项目经理审批 人事主管审批同意后才能请假成功。

示例图

image.png

示例代码

1.创建请假抽象对象LeaveBehaviour（抽象出请假的行为）

public abstract class LeaveBehaviour {

   protected  LeaveBehaviour nextleaveBehaviour;

   protected abstract void leave();

   public void setNextLeave(LeaveBehaviour nextleaveBehaviour){
      this.nextleaveBehaviour = nextleaveBehaviour;
   }



}

2.创建组长实现类GroupLeader 经理实现类Manager 人事实现类PersonnelMatters

public class GroupLeader extends  LeaveBehaviour{
    @Override
    protected void leave() {
        System.out.println("组长审批请假信息:同意");
        this.nextleaveBehaviour.leave();
    }
}

public class Manager extends LeaveBehaviour {
    @Override
    protected void leave() {
        System.out.println("经理审批请假信息:同意");
        this.nextleaveBehaviour.leave();
    }
}

public class PersonnelMatters extends  LeaveBehaviour {
    @Override
    protected void leave() {
        System.out.println("人事审批请假信息:同意");
    }
}

3.运行类Test

public class Test {
    public static void main(String[] args) {
        GroupLeader groupLeader = new GroupLeader();
        Manager manager = new Manager();
        PersonnelMatters personnelMatters = new PersonnelMatters();

        groupLeader.setNextLeave(manager);
        manager.setNextLeave(personnelMatters);
        groupLeader.leave();
    }
}

4.运行结果

image.png