标签：gof23 cte reason over 事件处理 ext struts2 存在 责任链
责任链模式chain of responsibility
将能够处理同一类请求的对象连成一条链，所提交的请求依次在链上传递，直到传递至有能力处理该请求的对象，不能则传给链上下一个
场景：
-打牌时
-奖学金审批
-请假审批
核心：是在客户端中才成链，也可以通过配置文件或者存在数组中加载
开发中常见场景：
-try catch异常链
-javascript语言中，事件的冒泡和捕获机制 Java语言中，事件处理采用观察者模式
-Servlet开发中，过滤器的链式处理
-Struts2中，拦截器的调用也是典型的链式处理
例子：工作中请假
0-3主任审批 3-10经理审批 10-30总经理审批
/**
* 请假条
* @author 小帆敲代码
*
*/
public class LeaveRequest {
private String empName;
private int leaveDays;
private String reason;
public String getEmpName() {
return empName;
}
public void setEmpName(String empName) {
this.empName = empName;
}
public int getLeaveDays() {
return leaveDays;
}
public void setLeaveDays(int leaveDays) {
this.leaveDays = leaveDays;
}
public String getReason() {
return reason;
}
public void setReason(String reason) {
this.reason = reason;
}
public LeaveRequest(String empName, int leaveDays, String reason) {
this.empName = empName;
this.leaveDays = leaveDays;
this.reason = reason;
}
}
public abstract class Leader {
protected String leaderName;
protected Leader nextLeader;//责任链中的后继对象
public Leader(String leaderName) {
this.leaderName = leaderName;
}
//设置下一级领导
public void setNetLeader(Leader leader) {
this.nextLeader=leader;
}
//业务方法处理请假条
public abstract void handler(LeaveRequest leaveRequest) ;
}
public class Director extends Leader{
public Director(String leaderName) {
super(leaderName);
}
@Override
public void handler(LeaveRequest leaveRequest) {
if(leaveRequest.getLeaveDays()<3) {
System.out.println("员工："+leaveRequest.getEmpName()+"，请假："+leaveRequest.getLeaveDays()+",原因："+leaveRequest.getReason());
System.out.println("主任:"+this.leaderName+",审核通过！");
}else {
if(this.nextLeader!=null) {
nextLeader.handler(leaveRequest);
}else {
System.out.println("此员工可能想辞职");
}
}
}
}
public class Manager extends Leader{
public Manager(String leaderName) {
super(leaderName);
}
@Override
public void handler(LeaveRequest leaveRequest) {
if(leaveRequest.getLeaveDays()<10) {
System.out.println("员工："+leaveRequest.getEmpName()+"，请假："+leaveRequest.getLeaveDays()+",原因："+leaveRequest.getReason());
System.out.println("经理:"+this.leaderName+",审核通过！");
}else {
if(this.nextLeader!=null) {
nextLeader.handler(leaveRequest);
}else {
System.out.println("此员工可能想辞职");
}
}
}
}
public class GeneralManager extends Leader{
public GeneralManager(String leaderName) {
super(leaderName);
}
@Override
public void handler(LeaveRequest leaveRequest) {
if(leaveRequest.getLeaveDays()<30) {
System.out.println("员工："+leaveRequest.getEmpName()+"，请假："+leaveRequest.getLeaveDays()+",原因："+leaveRequest.getReason());
System.out.println("总经理:"+this.leaderName+",审核通过！");
}else {
if(this.nextLeader!=null) {
nextLeader.handler(leaveRequest);
}else {
System.out.println("此员工可能想辞职");
}
}
}
}
public class Client {
public static void main(String[] args) {
Leader a=new Director("张三");
Leader b=new Manager("李四");
Leader c=new GeneralManager("王五");
//开始组织责任链
a.setNetLeader(b);
b.setNetLeader(c);
LeaveRequest req1=new LeaveRequest("TOM", 2, "抓JACK");
a.handler(req1);
}
}
设计模式之GOF23责任链模式
标签：gof23 cte reason over 事件处理 ext struts2 存在 责任链
原文地址：https://www.cnblogs.com/code-fun/p/11357189.html
