职责链设计模式解读

1. public class PurchaseRequest {
2. private int type = 0; //请求类型
3. private float price = 0.0f; //请求金额
4. private int id = 0;
5. 
6. //构造器
7. public PurchaseRequest(int type, float price, int id) {
8. this.type = type;
9. this.price = price;
10. this.id = id;
11.     }
12. 
13. public int getType() {
14. return type;
15.     }
16. 
17. public float getPrice() {
18. return price;
19.     }
20. 
21. public int getId() {
22. return id;
23.     }
24. 
25. }

1. public abstract class Approver {
2.     Approver approver;//下一个处理者
3.     String name;//名字
4. public Approver(String name) {
5. this.name = name;
6.     }
7. //下一个处理者
8. public void setApprover(Approver approver) {
9. this.approver = approver;
10.     }
11. //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
12. public abstract void processRequest(PurchaseRequest purchaseRequest);
13. 
14. }

1. public class ViceSchoolMasterApprover extends  Approver{
2. public ViceSchoolMasterApprover(String name) {
3. super(name);
4.     }
5. 
6. @Override
7. public void processRequest(PurchaseRequest purchaseRequest) {
8. if(purchaseRequest.getPrice() < 10000 && purchaseRequest.getPrice() <= 30000) {
9.             System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
10.         }else {
11.             approver.processRequest(purchaseRequest);
12.         }
13.     }
14. }

1. public class DepartmentApprover extends  Approver{
2. public DepartmentApprover(String name) {
3. super(name);
4.     }
5. 
6. @Override
7. public void processRequest(PurchaseRequest purchaseRequest) {
8. if(purchaseRequest.getPrice() <= 5000) {
9.             System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
10.         }else {
11.             approver.processRequest(purchaseRequest);
12.         }
13.     }
14. }

1. public class CollegeApprover extends  Approver{
2. public CollegeApprover(String name) {
3. super(name);
4.     }
5. 
6. @Override
7. public void processRequest(PurchaseRequest purchaseRequest) {
8. if(purchaseRequest.getPrice() < 5000 && purchaseRequest.getPrice() <= 10000) {
9.             System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
10.         }else {
11.             approver.processRequest(purchaseRequest);
12.         }
13.     }
14. }

1. public class SchoolMasterApprover extends  Approver{
2. 
3. public SchoolMasterApprover(String name) {
4. super(name);
5.     }
6. 
7. @Override
8. public void processRequest(PurchaseRequest purchaseRequest) {
9. if(purchaseRequest.getPrice() > 30000) {
10.             System.out.println(" 请求编号 id= " + purchaseRequest.getId() + " 被 " + this.name + " 处理");
11.         }else {
12.             approver.processRequest(purchaseRequest);
13.         }
14.     }
15. }

1. public class Client {
2. public static void main(String[] args) {
3. PurchaseRequest purchaseRequest = new PurchaseRequest(1, 31000, 1);
4. //创建相关的审批人
5. DepartmentApprover departmentApprover = new DepartmentApprover("张主任");
6. CollegeApprover collegeApprover = new CollegeApprover("李院长");
7. ViceSchoolMasterApprover viceSchoolMasterApprover = new ViceSchoolMasterApprover("王副校");
8. SchoolMasterApprover schoolMasterApprover = new SchoolMasterApprover("佟校长");
9. //需要将各个审批级别的下一个设置好 (处理人构成环形: )
10.         departmentApprover.setApprover(collegeApprover);
11.         collegeApprover.setApprover(viceSchoolMasterApprover);
12.         viceSchoolMasterApprover.setApprover(schoolMasterApprover);
13.         schoolMasterApprover.setApprover(departmentApprover);
14.         departmentApprover.processRequest(purchaseRequest);
15.         viceSchoolMasterApprover.processRequest(purchaseRequest);
16.     }
17. }