227 lines
6.2 KiB
Markdown
227 lines
6.2 KiB
Markdown
## 任务名称: 点赞和收藏动态
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### 目标:
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- 巩固练习： 熟练掌握基于spring boot开发的基本步骤
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### 预备知识:
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### 操作步骤:
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#### 1. API文档
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[点赞和取消点赞接口](../api%20doc/点赞和取消点赞接口.md)
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[获取当前用户对某个动态的点赞状态接口](../api%20doc/获取当前用户对某个动态的点赞状态接口.md)
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[收藏和取消收藏接口](../api%20doc/收藏和取消收藏接口.md)
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[获取当前用户对某个动态的收藏状态接口](../api%20doc/获取当前用户对某个动态的收藏状态接口.md)
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#### 2. 数据模型设计和实现
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##### 2.1 实体类
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**PostStar**
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```java
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@Entity
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public class PostStar extends BaseAuditingEntity{
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@Comment("POST ID")
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@ManyToOne(fetch = FetchType.LAZY)
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@JoinColumn(name = "post_id", nullable = false)
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private Post post;
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@Comment("用户ID")
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@ManyToOne(fetch = FetchType.LAZY)
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@JoinColumn(name = "user_id", nullable = false)
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private User user;
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}
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```
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**PostCollection**
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```java
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@Entity
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public class PostCollection extends BaseAuditingEntity{
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@Comment("POST ID")
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@ManyToOne(fetch = FetchType.LAZY)
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@JoinColumn(name = "post_id", nullable = false)
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private Post post;
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@Comment("用户ID")
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@ManyToOne(fetch = FetchType.LAZY)
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@JoinColumn(name = "user_id", nullable = false)
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private User user;
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}
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```
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##### 2.2 DTO
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**PostStarDTO**
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```java
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@Value
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public class PostStarDto {
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Long id;
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PostDto post;
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UserDto user;
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@JsonSerialize(using = MillisecondToSecondSerializer.class)
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Long createdOn;
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@JsonSerialize(using = MillisecondToSecondSerializer.class)
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Long modifiedOn;
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}
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```
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**PostCollectionDTO**
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```java
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@Value
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public class PostCollectionDto {
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Long id;
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PostDto post;
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UserDto user;
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@JsonSerialize(using = MillisecondToSecondSerializer.class)
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Long createdOn;
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@JsonSerialize(using = MillisecondToSecondSerializer.class)
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Long modifiedOn;
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}
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```
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##### 2.3 Mapper
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**PostStarMapper**
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```java
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@Mapper(unmappedTargetPolicy = ReportingPolicy.IGNORE, componentModel = MappingConstants.ComponentModel.SPRING)
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public interface PostStarMapper {
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PostStar toEntity(PostStarDto postStarDto);
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PostStarDto toDto(PostStar postStar);
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@BeanMapping(nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE)
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PostStar partialUpdate(PostStarDto postStarDto, @MappingTarget PostStar postStar);
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}
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```
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**PostCollectionMapper**
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```java
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@Mapper(unmappedTargetPolicy = ReportingPolicy.IGNORE, componentModel = MappingConstants.ComponentModel.SPRING)
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public interface PostCollectionMapper {
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PostCollection toEntity(PostCollectionDto postCollectionDto);
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PostCollectionDto toDto(PostCollection postCollection);
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@BeanMapping(nullValuePropertyMappingStrategy = NullValuePropertyMappingStrategy.IGNORE)
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PostCollection partialUpdate(PostCollectionDto postCollectionDto, @MappingTarget PostCollection postCollection);
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}
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```
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#### 3. JPA接口
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**PostStarRepository**
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```java
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public interface PostStarRepository extends JpaRepository<PostStar, Long> {
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Optional<PostStar> findByUserIdAndPostId(Long postId, Long userId);
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}
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```
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**PostCollectionRepository**
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```java
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public interface PostCollectionRepository extends JpaRepository<PostCollection, Long> {
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Optional<PostCollection> findByUserIdAndPostId(Long userId, Long postId);
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}
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```
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#### 4. 业务逻辑
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在PostService中添加处理点赞的方法：
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```java
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/**
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* 判断当前用户是对指定文章否已点赞
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* @param postId
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* @return
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*/
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public boolean currentUserHasStarred(Long postId){
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User user = authService.getCurrentUser();
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return postStarRepository.findByUserIdAndPostId(user.getId(), postId).isPresent();
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}
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/**
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* 点赞文章
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* @param postId 文章ID
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* @return 如果点赞成功返回true，如果已点过赞则返回false
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*/
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public boolean toggleStar(long postId){
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// 获取当前用户
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User user = authService.getCurrentUser();
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// 确认文章存在
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Post post = postRepository.findById(postId).orElseThrow(()->new ResourceNotFoundException("Post","id="+postId));
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// 确认用户是否已点赞
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PostStar postStar = postStarRepository.findByUserIdAndPostId(user.getId(),postId).orElse(null);
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if(postStar==null){
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// 如果未点赞，则创建点赞记录并更新文章点赞数
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postStar = new PostStar();
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postStar.setPost(post);
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postStar.setUser(user);
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postStarRepository.save(postStar);
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post.setUpvoteCount(post.getUpvoteCount()+1);
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postRepository.save(post);
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return true;
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}
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// 如果已点赞，则删除点赞记录并更新文章点赞数
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postStarRepository.delete(postStar);
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post.setUpvoteCount(post.getUpvoteCount()-1);
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postRepository.save(post);
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return false;
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}
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```
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对于收藏的处理与点赞类似，不再赘述。
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#### 5. RestController
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在PostController中添加点赞相关的接口：
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```java
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@GetMapping("/post/star")
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public DataResult<Map<String, Boolean>> currentHasStarred(@PathParam("id") Long postId) {
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Map<String, Boolean> result = new HashMap<>();
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result.put("status", postService.currentUserHasStarred(postId));
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return ResultUtil.ok(result);
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}
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@PostMapping("/post/star")
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public DataResult<Map<String, Boolean>> toggleStar(@RequestBody Map<String, Long> payload) {
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boolean stared = postService.toggleStar(payload.get("id"));
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Map<String, Boolean> result = new HashMap<>();
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result.put("status", stared);
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return ResultUtil.ok(result);
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}
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```
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收藏的接口与点赞类似，不再赘述。
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### 技术/工具需求:
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- [列出完成任务所需的技术栈、工具、软件版本等。]
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### 成功标准:
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- [明确完成任务的评判标准，如代码功能实现、性能指标、测试通过条件等。]
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### 扩展学习(可选):
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- [提供一些额外学习资源或挑战性任务，鼓励学有余力的学生进一步探索。]
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### 评估与反馈:
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- [说明如何提交作业、代码审查的标准、或任何反馈收集机制。]
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### 时间估算:
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- [给出预计完成该任务所需的时间，帮助学生合理安排学习计划。] |