springboot基于MVC模式的考研论坛的设计与实现的代码

Spring Boot基于MVC模式（Model-View-Controller）开发考研论坛，可以分为三个主要部分：

1. **模型(Model)**:

   @Entity
   public class Topic {
       @Id
       private Long id;
       private String title;
       private User owner;
       // getters and setters
   }
   
   @Entity
   public class Post {
       @ManyToOne
       private Topic topic;
       private User author;
       private String content;
       // getters and setters
   }

2. **视图(View) & 控制器(Controller)**:

   @RestController
   public class ForumController {
       
       @GetMapping("/topics")
       public List<Topic> getTopics(@ModelAttribute("criteria") Criteria criteria) {
           return forumService.searchTopics(criteria);
       }

       @PostMapping("/topics/new")
       public ResponseEntity<?> createTopic(@RequestBody Topic topic) {
           forumService.saveTopic(topic);
           return ResponseEntity.ok().build();
       }

       // 更多方法，例如帖子创建、查看、评论等
       @GetMapping("/{topicId}/posts")
       public List<Post> getPosts(@PathVariable Long topicId) {
           return postService.getByTopicId(topicId);
       }
   }

3. **模板引擎与前端视图**:
使用Thymeleaf或FreeMarker等模板引擎来渲染HTML页面，展示数据。例如，展示帖子列表的视图：

   <ul>
       <li th:each="post : ${posts}">
           <a href="#post_{{post.id}}">{{post.title}}</a> by <span th:text="${post.author.username}"></span>
       </li>
   </ul>

4. **服务层(Service)**:

   @Service
   public class ForumService {
       @Autowired
       private TopicRepository topicRepository;
       @Autowired
       private PostRepository postRepository;

       public List<Topic> searchTopics(Criteria criteria) {
           // 查询逻辑，可能是SQL或者JPA
       }
       public void saveTopic(Topic topic) {
           topicRepository.save(topic);
       }
   }