一、功能設(shè)計
點贊與收藏的邏輯是一樣的，這里就選取點贊功能來做開發(fā)。
按照本項目的設(shè)計，點贊業(yè)務(wù)涉兩個個方面：
- 要知道題目的點贊數(shù)
- 還要知道每個人點贊的題目
點贊的業(yè)務(wù)特性：頻繁。用戶一多，時時刻刻都在進行點贊，收藏等。如果采取傳統(tǒng)的數(shù)據(jù)庫模式，交互量是非常大的，很難抗住并發(fā)問題，所以采取 redis 的方式來做。
查詢的數(shù)據(jù)交互，可以和 redis 直接來做，持久化的數(shù)據(jù)，通過數(shù)據(jù)庫查詢即可，采取定時任務(wù) xxl-job 定期來刷數(shù)據(jù)，將數(shù)據(jù)同步到數(shù)據(jù)庫。
記錄的時候三個關(guān)鍵信息，點贊的人，被點贊的題目，點贊的狀態(tài)。
最終的數(shù)據(jù)結(jié)構(gòu)就是 hash，string，string 類型。
hash類型用于同步數(shù)據(jù)庫：key:value([hashKey, hashVal]...)有一個總key，value分為一個個hashKey和hashVal，此處hashKey定義為subjectId:userId，hashVal為status點贊狀態(tài)
第一個string類型存題目對應(yīng)點贊數(shù)key=subjectId，value=count點贊數(shù)；第二個string類型存題目對應(yīng)點贊人key=subjectId:userId，value="1"標(biāo)記點贊(該string與上面hash類似，在判斷當(dāng)前用戶是否點贊題目時處理方便)
數(shù)據(jù)庫設(shè)計：
二、基本功能開發(fā)
2.1 新增/取消點贊
直接操作redis，存hash，存題目數(shù)量+-1，存題目和點贊人的關(guān)聯(lián)
相關(guān)redisUtil：
public void putHash(String key, String hashKey, Object hashValue) {
redisTemplate.opsForHash().put(key, hashKey, hashValue);
}
public Integer getInt(String key) {
return (Integer) redisTemplate.opsForValue().get(key);
}
public void increment(String key, Integer count) {
redisTemplate.opsForValue().increment(key, count);
}
controller入口層
@PostMapping("/add")
public Result<Boolean> add(@RequestBody SubjectLikedDTO subjectLikedDto) {
try {
if (log.isInfoEnabled()) {
log.info("SubjectLikedController.add.dto:{}", JSON.toJSONString(subjectLikedDto));
}
Preconditions.checkNotNull(subjectLikedDto.getSubjectId(), "題目id不能為空");
Preconditions.checkNotNull(subjectLikedDto.getStatus(), "點贊狀態(tài)不能為空");
subjectLikedDto.setLikeUserId(LoginUtil.getLoginId());
Preconditions.checkNotNull(subjectLikedDto.getLikeUserId(), "點贊人不能為空");
SubjectLikedBO subjectLikedBO = SubjectLikedDTOConvert.INSTANCE.subjectLikedDtoToBo(subjectLikedDto);
subjectLikedDomainService.add(subjectLikedBO);
return Result.ok(true);
} catch (Exception e) {
log.info("SubjectLikedController.add.error:{}", e.getMessage(), e);
return Result.fail("題目點贊失敗");
}
}
點贊狀態(tài)枚舉類
@Getter
public enum SubjectLikedStatusEnum {
LIKED(1, "點贊"),
UN_LIKED(0, "未點贊");
private int code;
private String desc;
SubjectLikedStatusEnum(int code, String desc) {
this.code = code;
this.desc = desc;
}
}
domain防腐層
private String buildSubjectLikedKey(String subjectId, String likeUserId) {
return subjectId + ":" + likeUserId;
}
@Resource
private RedisUtil redisUtil
/**
* 點贊hash的總key
*/
private static final String SUBJECT_LIKED_KEY = "subject.liked"
/**
* 題目點贊數(shù)key前綴
*/
private static final String SUBJECT_LIKED_COUNT_KEY = "subject.liked.count"
/**
* 題目點贊人key前置
*/
private static final String SUBJECT_LIKED_DETAIL_KEY = "subject.liked.detail"
/**
* 新增/取消點贊
* @return
*/
@Override
public void add(SubjectLikedBO subjectLikedBO) {
String likeUserId = subjectLikedBO.getLikeUserId()
Long subjectId = subjectLikedBO.getSubjectId()
Integer status = subjectLikedBO.getStatus()
String hashKey = buildSubjectLikedKey(subjectId.toString(), likeUserId)
redisUtil.putHash(SUBJECT_LIKED_KEY, hashKey, status)
String countKey = SUBJECT_LIKED_COUNT_KEY + "." + subjectId
String detailKey = SUBJECT_LIKED_DETAIL_KEY + "." + subjectId + "." + likeUserId
if(SubjectLikedStatusEnum.LIKED.getCode() == status) { //點贊狀態(tài)
redisUtil.increment(countKey, 1)
redisUtil.set(detailKey, "1")
} else {
Integer count = redisUtil.getInt(countKey)
if(Objects.isNull(count) || count <= 0) { //當(dāng)數(shù)量不存在或為0時直接結(jié)束
return
}
redisUtil.increment(countKey, -1)
redisUtil.del(detailKey)
}
}
2.2 題目詳情增加點贊數(shù)據(jù)
此處涉及兩個功能：查詢當(dāng)前題目被點贊的數(shù)量，查詢當(dāng)前題目被當(dāng)前用戶是否點過贊
直接與reids交換，查詢key即可
subjectLiked的domain層實現(xiàn)以上兩個功能：
@Override
public Boolean isLiked(String subjectId, String userId) {
String detailKey = SUBJECT_LIKED_DETAIL_KEY + "." + subjectId + "." + userId;
return redisUtil.exist(detailKey);
}
@Override
public Integer getLikedCount(String subjectId) {
String countKey = SUBJECT_LIKED_COUNT_KEY + "." + subjectId;
Integer count = redisUtil.getInt(countKey);
if(Objects.isNull(count) || count <= 0) {
count = 0;
}
return count;
}
在獲取題目詳情的返回值基礎(chǔ)上添加題目點贊數(shù)和當(dāng)前用戶是否點贊屬性，最后在domain層組裝
在subjectInfoDTO和BO中添加private Boolean liked(是否被當(dāng)前用戶點贊); private Integer likedCount(題目點贊數(shù)量);
domain層組裝：
@Override
public SubjectInfoBO querySubjectInfo(SubjectInfoBO subjectInfoBO) {
if(log.isInfoEnabled()) {
log.info("SubjectInfoDomainService.querySubjectInfo.subjectInfoBO:{}", JSON.toJSONString(subjectInfoBO))
}
//先查詢題目主表數(shù)據(jù)
SubjectInfo subjectInfo = subjectInfoServices.queryById(subjectInfoBO.getId())
//工廠 + 策略 查詢具體類型題目的數(shù)據(jù)
SubejctTypeHandler handler = subjectTypeHandlerFactory.getHandler(subjectInfo.getSubjectType())
SubjectOptionBO subjectOptionBO = handler.query(subjectInfoBO.getId())
//將主表數(shù)據(jù)info 和 具體題目數(shù)據(jù)(答案、選項信息) 一起轉(zhuǎn)為 infoBo
SubjectInfoBO bo = SubjectInfoBOConvert.INSTANCE.subjectOptionBoAndInfoToBo(subjectInfo, subjectOptionBO)
//查詢標(biāo)簽id->標(biāo)簽name
SubjectMapping subjectMapping = new SubjectMapping()
subjectMapping.setSubjectId(bo.getId())
subjectMapping.setIsDeleted(IsDeletedFlagEnum.UN_DELETED.getCode())
List<SubjectMapping> subjectMappingList = subjectMappingService.queryByLabelId(subjectMapping)
List<Long> labelIds = subjectMappingList.stream().map(SubjectMapping::getLabelId).collect(Collectors.toList())
List<SubjectLabel> subjectLabelList = subjectLabelService.queryByLabelIds(labelIds)
List<String> labelNames = subjectLabelList.stream().map(SubjectLabel::getLabelName).collect(Collectors.toList())
bo.setLabelName(labelNames)
//返回點贊數(shù)、是否點贊
Integer likedCount = subjectLikedDomainService.getLikedCount(bo.getId().toString())
Boolean liked = subjectLikedDomainService.isLiked(bo.getId().toString(), LoginUtil.getLoginId())
bo.setLikedCount(likedCount)
bo.setLiked(liked)
return bo
}
三、數(shù)據(jù)庫同步reids點贊數(shù)據(jù)
通過xxl-job每隔一秒向數(shù)據(jù)庫同步redis的hash點贊數(shù)據(jù)并刪除hash類型，因為間隔一秒執(zhí)行一次，所以當(dāng)并發(fā)量大時會有細(xì)微的延遲。
3.1 xxl-job執(zhí)行定時任務(wù)
@Component
@Log4j2
public class SyncLikedJob {
@Resource
private SubjectLikedDomainService subjectLikedDomainService;
@XxlJob("syncLikedJobHandler")
public void syncLikedJobHandler() throws Exception {
XxlJobHelper.log("syncLikedJobHandler.start");
try {
subjectLikedDomainService.syncLiked();
} catch (Exception e) {
XxlJobHelper.log("syncLikedJobHandler.error" + e.getMessage());
}
}
}
3.2 相關(guān)redisUtil
public Map<Object, Object> getHashAndDelete(String key) {
Map<Object, Object> map = new HashMap<>();
Cursor<Map.Entry<Object, Object>> scan = redisTemplate.opsForHash().scan(key, ScanOptions.NONE);
while (scan.hasNext()) {
Map.Entry<Object, Object> entry = scan.next();
map.put(entry.getKey(), entry.getValue());
redisTemplate.opsForHash().delete(key, entry.getKey());
}
return map;
}
3.3 domain層核心邏輯
@Override
public void syncLiked() {
Map<Object, Object> subjectLikedMap = redisUtil.getHashAndDelete(SUBJECT_LIKED_KEY)
if(log.isInfoEnabled()) {
log.info("syncLiked.subjectLikedMap:{}", JSON.toJSONString(subjectLikedMap))
}
if(subjectLikedMap.isEmpty()) {
return
}
//批量同步數(shù)據(jù)庫
List<SubjectLiked> subjectLikedList = new ArrayList<>()
subjectLikedMap.forEach((key, val) -> {
SubjectLiked subjectLiked = new SubjectLiked()
String[] split = key.toString().split(":")
subjectLiked.setSubjectId(Long.valueOf(split[0]))
subjectLiked.setLikeUserId(split[1])
subjectLiked.setStatus(Integer.valueOf(val.toString()))
subjectLikedList.add(subjectLiked)
})
subjectLikedService.batchInsert(subjectLikedList)
}
3.4 infra原子性操作
<insert id="batchInsert">
INSERT INTO subject_liked (subject_id, like_user_id, status, created_by, created_time, update_by, update_time)
VALUES
<foreach collection="list" item="item" separator=",">
(#{item.subjectId}, #{item.likeUserId}, #{item.status}, #{item.createdBy}, #{item.createdTime}, #{item.updateBy}, #{item.updateTime})
</foreach>
</insert>
四、我的點贊
直接與數(shù)據(jù)庫交換，分頁查詢即可。因為xxl-job每隔一秒同步一次數(shù)據(jù)，所以當(dāng)并發(fā)量大時，會有微小延遲。
SubjectLikedDTO和BO都要繼承PageInfo，并添加subjectName在頁面顯示
@PostMapping("/getSubjectLikedPage")
public Result<PageResult<SubjectLikedDTO>> getSubjectLikedPage(@RequestBody SubjectLikedDTO subjectLikedDTO) {
try {
if (log.isInfoEnabled()) {
log.info("SubjectLikedController.getSubjectLikedPage.dto:{}", JSON.toJSONString(subjectLikedDTO));
}
SubjectLikedBO subjectLikedBO = SubjectLikedDTOConvert.INSTANCE.subjectLikedDtoToBo(subjectLikedDTO);
PageResult<SubjectLikedBO> subjectLikedBOList = subjectLikedDomainService.getSubjectLikedPage(subjectLikedBO);
return Result.ok(subjectLikedBOList);
} catch (Exception e) {
log.info("SubjectLikedController.getSubjectLikedPage.error:{}", e.getMessage(), e);
return Result.fail("查詢點贊記錄失敗");
}
}
@Override
public PageResult<SubjectLikedBO> getSubjectLikedPage(SubjectLikedBO subjectLikedBO) {
PageResult<SubjectLikedBO> pageResult = new PageResult<>()
pageResult.setPageNo(subjectLikedBO.getPageNo())
pageResult.setPageSize(subjectLikedBO.getPageSize())
int start = (subjectLikedBO.getPageNo() - 1) * subjectLikedBO.getPageSize()
SubjectLiked subjectLiked = SubjectLikedBOConvert.INSTANCE.subjectLikedBoToSubjectLiked(subjectLikedBO)
subjectLiked.setLikeUserId(LoginUtil.getLoginId())
int count = subjectLikedService.countByCondition(subjectLiked)
if(count == 0) {
return pageResult
}
List<SubjectLiked> subjectLikedList = subjectLikedService.queryPage(subjectLiked, start, subjectLikedBO.getPageSize())
List<SubjectLikedBO> subjectLikedBOList = SubjectLikedBOConvert.INSTANCE.subjectLikedsToBos(subjectLikedList)
subjectLikedBOList.forEach(info -> {
SubjectInfo subjectInfo = subjectInfoService.queryById(info.getSubjectId())
info.setSubjectName(subjectInfo.getSubjectName())
})
pageResult.setRecords(subjectLikedBOList)
pageResult.setTotal(count)
return pageResult
}
<select id="countByCondition" resultType="java.lang.Integer">
SELECT count(1) FROM subject_liked where like_user_id = #{likeUserId} and status = 1 and is_deleted = 0
</select>
<select id="queryPage" resultMap="SubjectLikedMap">
SELECT * FROM subject_liked
where status = 1 and is_deleted = 0
and like_user_id = #{subjectLiked.likeUserId}
limit #{start}, #{pageSize}
</select>
五、Rocketmq優(yōu)化點贊業(yè)務(wù)
之前的業(yè)務(wù)中，通過redis的hash表來保存用戶的點贊數(shù)據(jù)，并配合xxl-job來定時刷到數(shù)據(jù)庫。這樣太過依賴redis和xxl-job的可靠性，數(shù)據(jù)量大時可能會丟失數(shù)據(jù)，在此使用mq，每當(dāng)用戶點贊題目后，直接與mysql交互。
domain層修改，SubjectLikedMessage主要有subjectId，likedUserId，status
@Override
public void add(SubjectLikedBO subjectLikedBO) {
String likeUserId = subjectLikedBO.getLikeUserId()
Long subjectId = subjectLikedBO.getSubjectId()
Integer status = subjectLikedBO.getStatus()
// String hashKey = buildSubjectLikedKey(subjectId.toString(), likeUserId)
// redisUtil.putHash(SUBJECT_LIKED_KEY, hashKey, status)
//將每次的點贊消息發(fā)送到mq中直接與數(shù)據(jù)庫交互，替換redis-hash表
SubjectLikedMessage subjectLikedMessage = new SubjectLikedMessage()
subjectLikedMessage.setSubjectId(subjectId)
subjectLikedMessage.setLikeUserId(likeUserId)
subjectLikedMessage.setStatus(status)
rocketMQTemplate.convertAndSend("subject-liked", JSON.toJSONString(subjectLikedMessage))
String countKey = SUBJECT_LIKED_COUNT_KEY + "." + subjectId
String detailKey = SUBJECT_LIKED_DETAIL_KEY + "." + subjectId + "." + likeUserId
if(SubjectLikedStatusEnum.LIKED.getCode() == status) { //點贊狀態(tài)
redisUtil.increment(countKey, 1)
redisUtil.set(detailKey, "1")
} else {
Integer count = redisUtil.getInt(countKey)
if(Objects.isNull(count) || count <= 0) { //當(dāng)數(shù)量不存在或為0時直接結(jié)束
return
}
redisUtil.increment(countKey, -1)
redisUtil.del(detailKey)
}
}
mq消費層
@Component
@RocketMQMessageListener(topic = "subject-liked", consumerGroup = "subject-group")
@Log4j2
public class SubjectLikedConsumer implements RocketMQListener<String> {
@Resource
private SubjectLikedDomainService subjectLikedDomainService;
@Override
public void onMessage(String message) {
log.info("SubjectLikedConsumer.onMessage.message:{}", message);
SubjectLikedBO subjectLikedBO = JSON.parseObject(message, SubjectLikedBO.class);
subjectLikedDomainService.syncLikedMsg(subjectLikedBO);
}
}
syncLikedMsg方法與數(shù)據(jù)庫交互
@Override
public void syncLikedMsg(SubjectLikedBO subjectLikedBO) {
//同步到數(shù)據(jù)庫
SubjectLiked subjectLiked = new SubjectLiked()
subjectLiked.setSubjectId(subjectLikedBO.getSubjectId())
subjectLiked.setLikeUserId(subjectLikedBO.getLikeUserId())
subjectLiked.setStatus(subjectLikedBO.getStatus())
subjectLiked.setIsDeleted(IsDeletedFlagEnum.UN_DELETED.getCode())
List<SubjectLiked> subjectLikedList = new LinkedList<>()
subjectLikedList.add(subjectLiked)
subjectLikedService.batchInsertOrUpdate(subjectLikedList)
}
六、點贊數(shù)據(jù)不更新BUG修復(fù)
在上述的操作中，用戶每次點贊和取消點贊都會保存到數(shù)據(jù)庫，導(dǎo)致同一個用戶id，同一個題目id，在數(shù)據(jù)庫中有點贊和未點贊兩個狀態(tài)，當(dāng)用戶查詢我的點贊時，會從頭到尾遍歷數(shù)據(jù)庫status為1的題目，當(dāng)用戶先點贊后取消點贊時，題目仍在我的點贊列表中。
通過為subjectId和likedUserId建立唯一索引來保證subject_id 和 like_user_id 的組合值必須是唯一的，不能有重復(fù)記錄。
ALTER TABLE subject_liked ADD UNIQUE KEY unique_subject_like (subject_id, like_user_id);
向表中添加一個名為unique_subject_like的唯一索引。
同時修改插入點贊數(shù)據(jù)的sql語句：
<insert id="batchInsertOrUpdate">
INSERT INTO subject_liked
(subject_id, like_user_id, status, created_by, created_time, update_by, update_time, is_deleted)
VALUES
<foreach collection="entities" item="item" separator=",">
(
</foreach>
ON DUPLICATE KEY UPDATE
status = VALUES(status),
created_by = VALUES(created_by),
created_time = VALUES(created_time),
update_by = VALUES(update_by),
update_time = VALUES(update_time),
is_deleted = VALUES(is_deleted)
</insert>
ON DUPLICATE KEY UPDATE: 當(dāng)插入的數(shù)據(jù)違反唯一鍵約束時，會觸發(fā)此更新操作。VALUES() 函數(shù)用于獲取插入語句中對應(yīng)列的值，將這些值更新到已存在的記錄中。
?轉(zhuǎn)自https://juejin.cn/post/7463393885961437218
該文章在 2025/4/19 8:49:36 編輯過
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