java实现点赞功能

本文实例为大家分享了Java实现点赞功能的具体代码，供大家参考，具体内容如下

实现思路：

将点赞的数据先保存到Redis中，然后定时同步到数据库

第一步：

在redis中创建二个hash 用于存储 用户点赞记录及记录点赞数
MAP_USER_LIKED :用户点赞的记录 key:记录id::用户id value:1
MAP_USER_LIKED_COUNT:记录点赞数 key: 记录id value:数量

第二步：

创建枚举类

@Getter
public enum LikeStatusEnum {
  LIKE(1,"点赞"),
  UNLIKE(0,"取消点赞/未点赞");

  private Integer code;
  private String msg;

  LikeStatusEnum(Integer code,String msg){
    this.code = code;
    this.msg = msg;
  }
}

@Getter
public enum RedisHashEnum {
  MAP_USER_LIKED("MAP_USER_LIKED"),
  MAP_USER_LIKED_COUNT("MAP_USER_LIKED_COUNT");
  private String value;

  RedisHashEnum(String value){
    this.value =value;
  }
}

第三步：

将实现类写好

@Service
public class PostRedisServiceImpl implements PostRedisService {

  @Resource
  private RedisTemplate redisTemplate;

  @Autowired(required = false)
  public void setRedisTemplate(RedisTemplate redisTemplate){
    RedisSerializer serializer = new StringRedisSerializer();
    redisTemplate.setKeySerializer(serializer);
    redisTemplate.setValueSerializer(serializer);
    redisTemplate.setHashKeySerializer(serializer);
    redisTemplate.setHashValueSerializer(serializer);
    this.redisTemplate = redisTemplate;
  }
  /**
  * 点赞、取消点赞
  *
  * @param recordId
  * @param userId
  */
  @Override
  public void saveLikeRedis(String recordId, String userId,Integer status) {
    String key =recordId+"::"+userId;
    redisTemplate.opsForHash().put(RedisHashEnum.MAP_USER_LIKED,key, status);
  }

  /**
  * 从Redis中删除一条点赞数
  *
  * @param recordId
  * @param userId
  */
  @Override
  public void deleteLikeFromRedis(String recordId, String userId) {
    String key =recordId+"::"+userId;
    redisTemplate.opsForHash().delete(RedisHashEnum.MAP_USER_LIKED,key);
  }

  /**
  * 该记录 点赞加1
  *
  * @param recordId
  */
  @Override
  public void incrementLikedCount(String recordId) {
    redisTemplate.opsForHash().increment(RedisHashEnum.MAP_USER_LIKED_COUNT,recordId,1);
  }

  /**
  * 譔记录 点赞减1
  *
  * @param recordId
  */
  @Override
  public void decrementLikeCount(String recordId) {
    redisTemplate.opsForHash().increment(RedisHashEnum.MAP_USER_LIKED_COUNT,recordId,-1);
  }
}

第四步提供接口：

/**
  * 进行点赞、取消点赞
  *
  * @param vo
  */
  @Override
  public Result addKuDOS(KudosVo vo) {
    if(vo == null){
      return Result.error(ResponseMessage.PARAMERROR);
    }
    if("1".equals(vo.getStatus())){
      // 点赞
      postRedisService.saveLikeRedis(vo.getRecordId(),vo.getUserId(), LikeStatusEnum.LIKE.getCode());
      // 记录+1
      postRedisService.incrementLikedCount(vo.getRecordId());
    }else if("0".equals(vo.getStatus())){
      // 取消点赞 更新状态
      postRedisService.saveLikeRedis(vo.getRecordId(),vo.getUserId(), LikeStatusEnum.UNLIKE.getCode());

//      postRedisService.deleteLikeFromRedis(vo.getRecordId(),vo.getUserId());
      // 记录 -1
      postRedisService.decrementLikeCount(vo.getRecordId());
    }
    return Result.success(ResponseMessage.SUCCESS);
  }

最后定时将redis 中的数据同步到数据库

/**每 5 分钟执行一次
  * 将点赞人员同步到库中
  * */
//  @Transactional(rollbackFor =Exception.class)
  @Scheduled(cron = "0 */5 * * * ?")
  public void transLikdedFromRedis()throws IOException{
    List<RedisLikedUserDTO> dtoList = getLikedUserFromRedis();
    dtoList.stream().forEach(x->{
      // 通过记录及人员id 查询 该 人员是否点赞
      LambdaQueryWrapper<WorkCircleRecord> queryWrapper = new LambdaQueryWrapper<>();
      queryWrapper.eq(WorkCircleRecord::getDeleteIf,true);
      queryWrapper.eq(WorkCircleRecord::getId,x.getRecordId());
      queryWrapper.like(WorkCircleRecord::getWorkKudosUserIds,x.getUserId());
      WorkCircleRecord record = workCircleRecordMapper.selectOne(queryWrapper);
      // 点赞http://www.cppcns.com
      if(record == null&&"1".equals(x.getStatus())){
        // 根据记录id 查询
        LambdaQueryWrapper<WorkCircleRecord> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(WorkCircleRecord::getDeleteIf,true);
        wrapper.eq(WorkCircleRecord::getId,x.getRecordId());
        WorkCircleRecord workCircleRecord = workCircleRecordMapper.selectOne(wrapper);
        if(workCircleRecord != null){
          // 没有此人员 添加
          if(StringUtils.isBlank(workCircleRecord.getWorkKudosUserIds())){
            // 没有点赞人员
            workCircleRecord.setWorkKudosUserIds(x.getUserId());
            SysUser user = sysUserMapper.selectById(x.getUserId());
            if(user !=null){
              workCircleRecord.setWorkKudosUser(user.getRealname());
            }
          }else {
            // 有点赞人员
            String userIds = x.getUserId()+","+workCircleRecord.getWorkKudosUserIds();
            workCircleRecord.setWorkKudosUserIds(userIds);
            SysUser user = sysUserMapper.selectById(x.getUserId());
            String userNames = user.getRealname()+workCircleRecord.getWorkKudosUser();
            workCircleRecord.setWorkKudosUser(userNames);
          }
          workCircleRecordMapper.updateById(workCircleRecord);
        }

      }else if("0".equals(x.getStatus())) {
        // 有记录 并取消点赞
        // 根据记录id 查询
        LambdaQueryWrapper<WorkCircleRecord> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(WorkCircleRecord::getDeleteIf,true);
        wrapper.eq(WorkCircleRecord::getId,x.getRecordId());
        WorkCircleRecord workCircleRecord = workCircleRecordMapper.selyzjfKGZhYectOne(wrapper);
        // 将此点赞人员去除
        if(workCircleRecord !=null){
          SysUser user = sysUserMapper.selectById(x.getUserId());
          List<String> userIds = Arrays.asList(workCircleRecord.getWorkKudosUserIds().split(","));
          List<String> userNames =Arrays.asList(workCircleRecord.getWorkKudosUser().split(","));
          userIds.remove(x.getUserId());
          userNames.remove(user.getRealname());
          workCircleRecord.setWorkKudosUserIds(String.join(",",userIds));
          workCircleRecord.setWorkKudosUser(String.join(",",userNames));
          workCircleRecordMapper.updateById(workCircleRecord);
        }
      }
    });
  }

/**获取 所有点赞的人员
  * */
  public List<RedisLikedUserDTO> getLikedUserFromRedis() throws IOException{
    List<RedisLikedUserDTO> dtoList = new ArrayList<>();
    // 通过游标获取所有键值对
    Cursor<Map.Entry<Object,Object>> cursor = redisTemplate.opsForHash().scan(RedisHashEnum.MAP_USER_LIKED.getValue(),ScanOptions.N编程ONE);
    while (cursor.hasNext()){
      Map.Entry<Object,Object> map = cursor.next();
      String key = map.getKey().toString();
      String[] split = key.split("::");
      RedisLikedUserDTO dto = new RedisLikedUserDTO();
      dto.setRecordId(split[0]);
      dto.setUserId(split[1]);
      dto.setStatus(Integer.parseInt(map.getValue().toString()));
      dtoList.add(dto);

      // 将redis 中的记录删除
      redisTemplate.opsForHash().delete(RedisHashEnum.MAP_USER_LIKED.getValue(),key);
    }
    cursor.close();
    return dtoList;
  }

/**每 5 分钟执行一次
  * 将点赞数同步到库中
  * */
  @Transactional(rollbackFor =Exception.class)
  @Scheduled(cron = "0 */5 * * * ?")
  public void transLikedCountFromRedis() throws IOException{
    // 获取所有的点赞数
    List<RedisLikeCountDTO> dtoList = getLikedCountFromRedis();
    // 获取所有的记录id
    List<String> recordIdList = dtoList.stream().map(x->x.getRecordId()).collect(Collectors.toList());
    if(CollectionUtils.isNotEmpty(recordIdList)){
      List<WorkCircleRecord> recordList = workCircleRecordMapper.selectBATchIds(recordIdList);
      if(CollectionUtils.isNotEmpty(recordList)){
        // 通过id 匹配
        dtoList.stream().forEach(x->{
          recordList.stream().forEach(k->{
            if(x.getRecordId().equals(k.getId())){
              Integer num = x.getCount()+k.getWorkKudos();
              if(num<0){
                k.setWorkKudos(0);
              }else {
          javascript      k.setWorkKudos(num);
              }
              workCircleRecordMapper.updateById(k);
            }
          });
        });
      }
    }
  }

/** 取出所有的点赞数
  * */
  public List<RedisLikeCountDTO> getLikedCountFromRedis() throws IOException {
    List<RedisLikeCountDTO> dtoList = new ArrayList<>();
    Cursor<Map.Entry<Object,Object>> cursor= redisTemplate.opsForHash().scan(RedisHashEnum.MAP_USER_LIKED_COUNT, ScanOptions.NONE);
    while (cursor.hasNext()){
      Map.Entry<Object,Object> map = cursor.next();
      // 获取 点赞数
      String key = map.getKey().toString();
      RedisLikeCountDTO dto = new RedisLikeCountDTO();
      dto.setRecordId(key);
      dto.setCount(Integer.parseInt(map.getValue().toString()));
      dtoList.add(dto);
      redisTemplate.opsForHash().delete(RedisHashEnum.MAP_USER_LIKED_COUNT,key);
    }
    cursor.close();
    return dtoList;
  }

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