增加分布式锁解决多用户同时操作排序情况下序号混乱的问题。

src/main/java/com/huoran/iasf/controller/SysContentController.java

@@ -90,7 +90,10 @@ public class SysContentController {
         queryWrap.eq("column_id", sysContent.getColumnId());
         queryWrap.eq("deleted", 1);
         Integer count = service.count(queryWrap);
-        sysContent.setSequence(count++);
+        if (count == 0) {
+            count = 1;
+        }
+        sysContent.setSequence(count + 1);
         boolean addState = service.save(sysContent);
 
 
@@ -265,7 +268,6 @@ public class SysContentController {
     public R modifiedSort(
             @ApiParam(name = "sequenceNumber", value = "要排序的序号", required = true) @RequestParam Integer sequenceNumber,
             @ApiParam(name = "articleId", value = "文章Id", required = true) @RequestParam Integer articleId) {
-
         return service.modifiedSort(sequenceNumber, articleId);
     }
 
@@ -293,6 +295,7 @@ public class SysContentController {
             QueryWrapper<SysContent> queryWrap1 = new QueryWrapper<>();
             queryWrap1.eq("column_id", columnId);
             queryWrap1.eq("deleted", 1);
+            queryWrap1.orderByDesc("release_time");
             List<SysContent> list = service.list(queryWrap1);
 
             Integer count = 0;

src/main/java/com/huoran/iasf/service/impl/SysContentServiceImpl.java

@@ -14,11 +14,15 @@ import com.huoran.iasf.vo.req.ArticleModifiedSortReq;
 import com.huoran.iasf.vo.req.ContentHeavyTitleReqVO;
 import com.huoran.iasf.vo.req.PageContentReqVO;
 import com.huoran.iasf.vo.resp.PageContentRespVO;
+import org.springframework.data.redis.core.RedisTemplate;
 import org.springframework.data.redis.core.StringRedisTemplate;
 import org.springframework.stereotype.Service;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.*;
+import java.util.concurrent.TimeUnit;
 
 /**
  * @描述：文章管理 服务类
@@ -28,6 +32,7 @@ import java.util.*;
 @Service
 public class SysContentServiceImpl extends ServiceImpl<SysContentMapper, SysContent> implements SysContentService {
 
+    private final static Logger logger = LoggerFactory.getLogger(SysContentServiceImpl.class);
     @Autowired
     private SysContentMapper mapper;
 
@@ -148,61 +153,128 @@ public class SysContentServiceImpl extends ServiceImpl<SysContentMapper, SysCont
     @Override
     public R modifiedSort(Integer sequenceNumber, Integer articleId) {
 
+        // 占分布式锁，去redis占坑
+        // 1. 分布式锁占坑
+        Boolean lock = redisTemplate.opsForValue().setIfAbsent("articleSortLock", "value", 30, TimeUnit.SECONDS);
+        if (lock) {
+            //加锁成功...
             if (sequenceNumber <= 0) {
+                redisTemplate.delete("articleSortLock");   //删除key，释放锁
                 return R.fail("请输入正确的序号!");
             }
-
-
             SysContent content = baseMapper.selectById(articleId);
             //获取当前排序的序号
             Integer currentSerialNumber = content.getSequence();
             //获取当前文章所属栏目id
             Integer columnId = content.getColumnId();
 
-        //获取栏目下全部文章的数量与当前输入的序号判断 如果要更改的序号大于当前有的数量，直接替换
-        QueryWrapper<SysContent> queryWrapper = new QueryWrapper<>();
-        queryWrapper.eq("column_id", columnId);
-        queryWrapper.eq("deleted", 1);
-        List<SysContent> contentList = baseMapper.selectList(queryWrapper);
-        if (sequenceNumber >= contentList.size()) {
-            sequenceNumber = contentList.size();
-        }
-
-
             if (currentSerialNumber.equals(sequenceNumber)) {
+                redisTemplate.delete("articleSortLock");   //删除key，释放锁
                 return R.success();
             }
-
-
             //修改当前序号
             UpdateWrapper<SysContent> updateWrapper = new UpdateWrapper<>();
             updateWrapper.set("sequence", sequenceNumber);
             updateWrapper.eq("id", articleId);
-        baseMapper.update(new SysContent(), updateWrapper);
+            //做乐观锁处理
+            updateWrapper.eq("sequence", currentSerialNumber);
+            int updateCount = baseMapper.update(new SysContent(), updateWrapper);
 
             UpdateWrapper<SysContent> updateWrapper1 = new UpdateWrapper<>();
             updateWrapper1.ne("id", articleId);
-        // 序号越小值越算大
             //currentSerialNumber 当前文章的序号
             //sequenceNumber 要更改的序号
+
+            /**
+             * 就要判断排序是值改小还是改大
+             * 大改小比如53改5那就加一个语句“大于等于5并且小于53”
+             * 如果是小改大比如3改50那就是“大于3并且小于等于50"
+             */
             if (currentSerialNumber > sequenceNumber) {
                 //改大 gt >
                 updateWrapper1.setSql("  sequence = sequence + 1");
                 updateWrapper1.last(" and sequence >= " + sequenceNumber + " and sequence < " + currentSerialNumber);
             } else if (currentSerialNumber < sequenceNumber) {
                 //改小
-            updateWrapper1.le("sequence", sequenceNumber);
+                //le为<=
+//                updateWrapper1.le("sequence", sequenceNumber);
                 updateWrapper1.setSql("  sequence = sequence - 1");
+                updateWrapper1.last(" and sequence > " + currentSerialNumber + " and sequence <= " + sequenceNumber);
                 //用于判断序号为本身就为1时候就不减了
-            updateWrapper1.ne("sequence", 1);
+//                updateWrapper1.ne("sequence", 1);
             }
 
             updateWrapper1.eq("column_id", columnId);
             updateWrapper1.eq("deleted", 1);
             baseMapper.update(new SysContent(), updateWrapper1);
+            redisTemplate.delete("articleSortLock");   //删除key，释放锁
             return R.success();
+        } else {
+            return R.fail("当前有用户操作排序，请稍后刷新重试!");
+        }
+
+
     }
 
+    /*@Override
+    public R modifiedSort(Integer newIndex, Integer articleId,Integer sort) {
+        if (newIndex <= 0) {
+            return R.fail("请输入正确的序号!");
+        }
+        //获取当前排序的序号
+        SysContent content = baseMapper.selectById(articleId);
+        //获取当前文章所属栏目id
+        Integer columnId = content.getColumnId();
+        //查看当前升序情况下全部文章信息
+        QueryWrapper<SysContent> queryWrapper = new QueryWrapper<>();
+        queryWrapper.eq("column_id", columnId);
+        queryWrapper.eq("deleted", 1);
+
+        if (sort==0){
+            queryWrapper.orderByAsc("sequence");
+        }else if (sort==1){
+            queryWrapper.orderByDesc("sequence");
+        }
+
+        List<SysContent> contentList = baseMapper.selectList(queryWrapper);
+        //获取当前序号在list中的顺序
+        int currentIndex = contentList.indexOf(content);
+        //获取当前排序的序号
+        Integer currentSerialNumber = content.getSequence();
+        if (currentIndex == -1) {
+            // 文章不存在，不做任何操作
+            return R.success();
+        }
+        //对于传过来的序号 处理用于匹配集合的下标
+        if (currentSerialNumber > newIndex) {
+            newIndex--;
+        }else {
+            newIndex++;
+        }
+
+        if (currentIndex == newIndex) {
+            // 新旧位置相同，不做任何操作
+            return R.success();
+        }
+        // 移除当前位置的文章
+        contentList.remove(content);
+        if (newIndex >= contentList.size()) {
+            // 插入到末尾
+            contentList.add(content);
+        } else {
+            // 插入到新位置
+            contentList.add(newIndex, content);
+        }
+        for (int i = 0; i < contentList.size(); i++) {
+            SysContent article = contentList.get(i);
+            article.setSequence(i + 1);
+            baseMapper.updateById(article);
+        }
+
+
+        return R.success();
+    }*/
+
 
 }