sprimgboot实现点赞功能代码实现

下面是一个简单的 Spring Boot 实现点赞功能的示例代码：

1. 点赞实体类

@Entity
public class Like {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private Long userId;
    private Long targetId;
    private LocalDateTime createTime;

    // getter 和 setter 略
}

2. 点赞服务

@Service
public class LikeService {
    @Autowired
    private LikeRepository likeRepository;

    public void like(Long userId, Long targetId) {
        Like like = new Like();
        like.setUserId(userId);
        like.setTargetId(targetId);
        like.setCreateTime(LocalDateTime.now());
        likeRepository.save(like);
    }

    public void unlike(Long userId, Long targetId) {
        likeRepository.deleteByUserIdAndTargetId(userId, targetId);
    }

    public Long count(Long targetId) {
        return likeRepository.countByTargetId(targetId);
    }
}

3. 点赞控制器

@RestController
@RequestMapping("/like")
public class LikeController {
    @Autowired
    private LikeService likeService;

    @PostMapping("/like")
    public void like(@RequestParam Long userId, @RequestParam Long targetId) {
        likeService.like(userId, targetId);
    }

    @PostMapping("/unlike")
    public void unlike(@RequestParam Long userId, @RequestParam Long targetId) {
        likeService.unlike(userId, targetId);
    }

    @GetMapping("/count")
    public Long count(@RequestParam Long targetId) {
        return likeService.count(targetId);
    }
}

4. 前端页面

<div>
    <button id="likeButton" onclick="like()">点赞</button>
    <span id="likeCount"></span>
</div>

<script>
    function like() {
        $.ajax({
            type: "POST",
            url: "/like/like",
            data: {
                userId: "1",
                targetId: "1001"
            },
            success: function() {
                $("#likeButton").attr("disabled", true);
                countLike();
            }
        });
    }

    function unlike() {
        $.ajax({
            type: "POST",
            url: "/like/unlike",
            data: {
                userId: "1",
                targetId: "1001"
            },
            success: function() {
                $("#likeButton").attr("disabled", false);
                countLike();
            }
        });
    }

    function countLike() {
        $.ajax({
            type: "GET",
            url: "/like/count",
            data: {
                targetId: "1001"
            },
            success: function(count) {
                $("#likeCount").text(count);
            }
        });
    }

    $(document).ready(function() {
        countLike();
    });
</script>

以上代码实现了一个简单的点赞功能，用户点击点赞按钮后，调用 AJAX 请求将点赞信息发送到后端控制器，然后后端服务将点赞信息保存到数据库中，并且更新点赞数的显示。如果用户取消点赞，则发送取消点赞请求，后端服务将相应的点赞信息从数据库中删除，并且更新点赞数的显示。