Handler
: 抽象的处理者, 定义了一个处理请求的接口, 同时含义另外Handler
ConcreteHandlerA , B
: 是具体的处理者, 处理它自己负责的请求, 可以访问它的后继者(即下一个处理者), 如果可以
处理当前请求,则处理,否则就将该请求交个 后继者去处理,从而形成一个职责链
Request
:含义很多属性,表示一个请求
编写程序完成学校OA系统的采购审批项目:需求采购员采购教学器材
//请求类
public class PurchaseRequest {
private int type = 0; //请求类型
private float price = 0.0f; //请求金额
private int id = 0;
//构造器
public PurchaseRequest(int type, float price, int id) {
this.type = type;
this.price = price;
this.id = id;
}
public int getType() {
return type;
}
public float getPrice() {
return price;
}
public int getId() {
return id;
}
}
public abstract class Approver {
Approver approver; //下一个处理者
String name; // 名字
public Approver(String name) {
this.name = name;
}
//下一个处理者
public void setApprover(Approver approver) {
this.approver = approver;
}
//处理审批请求的方法,得到一个请求, 处理是子类完成,因此该方法做成抽象
public abstract void processRequest(PurchaseRequest purchaseRequest);
}
public class CollegeApprover extends Approver {
public CollegeApprover(String name) {
super(name);
}
@Override
public void processRequest(PurchaseRequest purchaseRequest) {
if(purchaseRequest.getPrice() > 5000 && purchaseRequest.getPrice() <= 10000) {
System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
}else {
approver.processRequest(purchaseRequest);
}
}
}
public class DepartmentApprover extends Approver {
public DepartmentApprover(String name) {
super(name);
}
@Override
public void processRequest(PurchaseRequest purchaseRequest) {
if(purchaseRequest.getPrice() <= 5000) {
System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
}else {
approver.processRequest(purchaseRequest);
}
}
}
public class SchoolMasterApprover extends Approver {
public SchoolMasterApprover(String name) {
super(name);
}
@Override
public void processRequest(PurchaseRequest purchaseRequest) {
if(purchaseRequest.getPrice() > 30000) {
System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
}else {
approver.processRequest(purchaseRequest);
}
}
}
public class ViceSchoolMasterApprover extends Approver {
public ViceSchoolMasterApprover(String name) {
super(name);
}
@Override
public void processRequest(PurchaseRequest purchaseRequest) {
if(purchaseRequest.getPrice() > 10000 && purchaseRequest.getPrice() <= 30000) {
System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
}else {
approver.processRequest(purchaseRequest);
}
}
}
package com.ssm.responsibilitychain;
/**
* @author shaoshao
* @version 1.0
* @date 2022/6/3 12:10
*/
public class Client {
public static void main(String[] args) {
//创建一个请求
PurchaseRequest purchaseRequest = new PurchaseRequest(1, 1000, 1);
//创建相关的审批人
DepartmentApprover departmentApprover = new DepartmentApprover("张主任");
CollegeApprover collegeApprover = new CollegeApprover("李院长");
ViceSchoolMasterApprover viceSchoolMasterApprover = new ViceSchoolMasterApprover("王副校");
SchoolMasterApprover schoolMasterApprover = new SchoolMasterApprover("佟校长");
//需要将各个审批级别的下一个设置好 (处理人构成环形: )
departmentApprover.setApprover(collegeApprover);
collegeApprover.setApprover(viceSchoolMasterApprover);
viceSchoolMasterApprover.setApprover(schoolMasterApprover);
schoolMasterApprover.setApprover(departmentApprover);
departmentApprover.processRequest(purchaseRequest);
viceSchoolMasterApprover.processRequest(purchaseRequest);
schoolMasterApprover.processRequest(purchaseRequest);
}
}
setNext()
方法中判断是否已经超过阀值,超过则不允许该链建立,避免出现超长链无意识地破坏系统性能