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;
}
@Override
public void saveLikeRedis(String recordId, String userId,Integer status) {
String key =recordId+"::"+userId;
redisTemplate.opsForHash().put(RedisHashEnum.MAP_USER_LIKED,key, status);
}
@Override
public void deleteLikeFromRedis(String recordId, String userId) {
String key =recordId+"::"+userId;
redisTemplate.opsForHash().delete(RedisHashEnum.MAP_USER_LIKED,key);
}
@Override
public void incrementLikedCount(String recordId) {
redisTemplate.opsForHash().increment(RedisHashEnum.MAP_USER_LIKED_COUNT,recordId,1);
}
@Override
public void decrementLikeCount(String recordId) {
redisTemplate.opsForHash().increment(RedisHashEnum.MAP_USER_LIKED_COUNT,recordId,-1);
}
}第四步提供接口：
@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
// @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
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.selectOne(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);
}
}
});
}
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.NONE);
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;
}
@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 {
k.setWorkKudos(num);
}
workCircleRecordMapper.updateById(k);
}
});
});
}
}
}
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;
}以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持编程网。
