✨Feat: 增加点赞功能

src/main/java/cn/hezhaohui/thumb/service/impl/ThumbServiceImpl.java

@@ -1,10 +1,20 @@
 package cn.hezhaohui.thumb.service.impl;
 
+import cn.hezhaohui.thumb.exception.BusinessException;
+import cn.hezhaohui.thumb.exception.ErrorCode;
+import cn.hezhaohui.thumb.model.dto.DoThumbRequest;
+import cn.hezhaohui.thumb.model.entity.Blog;
+import cn.hezhaohui.thumb.model.entity.User;
+import cn.hezhaohui.thumb.service.BlogService;
+import cn.hezhaohui.thumb.service.UserService;
 import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
 import cn.hezhaohui.thumb.model.entity.Thumb;
 import cn.hezhaohui.thumb.service.ThumbService;
 import cn.hezhaohui.thumb.mapper.ThumbMapper;
+import jakarta.annotation.Resource;
+import jakarta.servlet.http.HttpServletRequest;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.support.TransactionTemplate;
 
 /**
 * @author 23117
@@ -15,6 +25,48 @@ import org.springframework.stereotype.Service;
 public class ThumbServiceImpl extends ServiceImpl<ThumbMapper, Thumb>
     implements ThumbService{
 
+    @Resource
+    private UserService userService;
+
+    @Resource
+    private BlogService blogService;
+
+    @Resource
+    private TransactionTemplate transactionTemplate;
+
+    @Override
+    public Boolean doThumb(DoThumbRequest doThumbRequest, HttpServletRequest request) {
+        if (doThumbRequest == null || doThumbRequest.getBlogId() == null) {
+            throw new RuntimeException("参数异常");
+        }
+        User loginUser = userService.getLoginUser(request);
+        // Lock: 这里使用字符串加锁，获取字符串常量对象才可运行，字符串常量对象具有唯一性
+        synchronized (("LOCK-USERID-" + loginUser.getId().toString()).intern()) {
+            // Transaction: 编程式事务
+            return transactionTemplate.execute(status -> {
+                Long blogId = doThumbRequest.getBlogId();
+                // 判断是否已点过赞
+                boolean exists = this.lambdaQuery()
+                        .eq(Thumb::getUserid, loginUser.getId())
+                        .eq(Thumb::getBlogId, blogId)
+                        .exists();
+                if (exists) {
+                    throw new BusinessException(ErrorCode.OPERATION_ERROR, "用户已点赞");
+                }
+                // 更新帖子点赞计数器
+                boolean update = blogService.lambdaUpdate()
+                        .eq(Blog::getId, blogId)
+                        .setSql("thumbCount = thumbCount + 1")
+                        .update();
+                // 更新点赞表数据
+                Thumb thumb = new Thumb();
+                thumb.setUserid(loginUser.getId());
+                thumb.setBlogId(blogId);
+                // 两者一起执行
+                return update && this.save(thumb);
+            });
+        }
+    }
 }