两种语言实现设计模式（C++和Java）（十四：责任链模式）

 1 #include <iostream>
 2 
 3 using namespace std;
 4 
 5 class Request{
 6 public:
 7     int level;
 8 };
 9 
10 class Manager{
11 public:
12     Manager(string _name){name = _name;}
13     void setSuccessor(Manager* manager){nextLevel = manager;}
14     virtual void GetRequest(Request* request)=0;
15 protected:
16     Manager* nextLevel;
17     string name;
18 };
19 
20 class ProjectManager:public Manager{
21 public:
22     ProjectManager(string _name):Manager(_name){}
23     virtual void GetRequest(Request *request){
24         if (request->level <= 1){
25             cout << name << " handle it" << endl;
26         } else {
27             nextLevel->GetRequest(request);
28         }
29     }
30 };
31 
32 class DepartmentManager:public Manager{
33 public:
34     DepartmentManager(string _name):Manager(_name){}
35     virtual void GetRequest(Request *request){
36         if (request->level <= 2){
37             cout << name << " handle it" << endl;
38         } else {
39             nextLevel->GetRequest(request);
40         }
41     }
42 };
43 
44 class President:public Manager{
45 public:
46     President(string _name):Manager(_name){}
47     virtual void GetRequest(Request *request){
48         cout << name << " handle it" << endl;
49     }
50 };
51 
52 int main()
53 {
54     Request *request = new Request();
55     request->level = 3;
56     Manager *projectManager = new ProjectManager("Project Manager: Alice");
57     Manager *departmentManager = new DepartmentManager("Department manager: Helen");
58     Manager *president = new President("President: Chalice");
59     projectManager->setSuccessor(departmentManager);
60     departmentManager->setSuccessor(president);
61     projectManager->GetRequest(request);
62     return 0;
63 }

 1 public class Request {
 2     int level;
 3 }
 4 
 5 public abstract class Manager {
 6 
 7     private Manager next;
 8 
 9     public void setNext(Manager next){
10         this.next = next;
11     }
12 
13     public Manager getNext(){
14         return next;
15     }
16 
17     public abstract void handleRequest(Request request);
18 }
19 
20 public class ProjectManager extends Manager {
21 
22     @Override
23     public void handleRequest(Request request) {
24         if (request.level <= 1){
25             System.out.println("Project Manager handle request");
26         } else {
27             this.getNext().handleRequest(request);
28         }
29     }
30 }
31 
32 public class DepartmentManager extends Manager {
33 
34     @Override
35     public void handleRequest(Request request) {
36         if (request.level <= 2){
37             System.out.println("Department manager handle request");
38         } else {
39             this.getNext().handleRequest(request);
40         }
41     }
42 }
43 
44 public class President extends Manager {
45 
46     @Override
47     public void handleRequest(Request request) {
48         System.out.println("President handle request");
49     }
50 }
51 
52 public class Main {
53 
54     public static void main(String[] args) {
55         Manager projectManager = new ProjectManager();
56         Manager departmentManager = new DepartmentManager();
57         Manager president = new President();
58         projectManager.setNext(departmentManager);
59         departmentManager.setNext(president);
60         Request request = new Request();
61         request.level = 3;
62         projectManager.handleRequest(request);
63     }
64 }