來源:juejin.im/post/5bdc257e6fb9a049ba410098 本文基于 SpringCloud, 用戶發(fā)起點(diǎn)贊、取消點(diǎn)贊后先存入 Redis 中,再每隔兩小時(shí)從 Redis讀取點(diǎn)贊數(shù)據(jù)寫入數(shù)據(jù)庫中做持久化存儲(chǔ)。 點(diǎn)贊功能在很多系統(tǒng)中都有,但別看功能小,想要做好需要考慮的東西還挺多的。 點(diǎn)贊、取消點(diǎn)贊是高頻次的操作,若每次都讀寫數(shù)據(jù)庫,大量的操作會(huì)影響數(shù)據(jù)庫性能,所以需要做緩存。 至于多久從 Redis 取一次數(shù)據(jù)存到數(shù)據(jù)庫中,根據(jù)項(xiàng)目的實(shí)際情況定吧,我是暫時(shí)設(shè)了兩個(gè)小時(shí)。 項(xiàng)目需求需要查看都誰點(diǎn)贊了,所以要存儲(chǔ)每個(gè)點(diǎn)贊的點(diǎn)贊人、被點(diǎn)贊人,不能簡(jiǎn)單的做計(jì)數(shù)。 文章分四部分介紹: - Redis 緩存設(shè)計(jì)及實(shí)現(xiàn)
- 開啟定時(shí)任務(wù)持久化存儲(chǔ)到數(shù)據(jù)庫
一、Redis 緩存設(shè)計(jì)及實(shí)現(xiàn)1.1 Redis 安裝及運(yùn)行Redis 安裝請(qǐng)自行查閱相關(guān)教程。
說下Docker 安裝運(yùn)行 Redis docker run -d -p 6379:6379 redis:4.0.8
如果已經(jīng)安裝了 Redis,打開命令行,輸入啟動(dòng) Redis 的命令 redis-server
1.2 Redis 與 SpringBoot 項(xiàng)目的整合1.在 pom.xml 中引入依賴 <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency>
2.在啟動(dòng)類上添加注釋 @EnableCaching @SpringBootApplication @EnableDiscoveryClient @EnableSwagger2 @EnableFeignClients(basePackages = 'com.solo.coderiver.project.client') @EnableCaching public class UserApplication {
public static void main(String[] args) { SpringApplication.run(UserApplication.class, args); } }
3.編寫 Redis 配置類 RedisConfig import com.fasterxml.jackson.annotation.JsonAutoDetect; import com.fasterxml.jackson.annotation.PropertyAccessor; import com.fasterxml.jackson.databind.ObjectMapper; import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.data.redis.connection.RedisConnectionFactory; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.core.StringRedisTemplate; import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import java.net.UnknownHostException;
@Configuration public class RedisConfig {
@Bean @ConditionalOnMissingBean(name = 'redisTemplate') public RedisTemplate<String, Object> redisTemplate( RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer<Object>(Object.class); ObjectMapper om = new ObjectMapper(); om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL); jackson2JsonRedisSerializer.setObjectMapper(om);
RedisTemplate<String, Object> template = new RedisTemplate<String, Object>(); template.setConnectionFactory(redisConnectionFactory); template.setKeySerializer(jackson2JsonRedisSerializer); template.setValueSerializer(jackson2JsonRedisSerializer); template.setHashKeySerializer(jackson2JsonRedisSerializer); template.setHashValueSerializer(jackson2JsonRedisSerializer); template.afterPropertiesSet(); return template; }
@Bean @ConditionalOnMissingBean(StringRedisTemplate.class) public StringRedisTemplate stringRedisTemplate( RedisConnectionFactory redisConnectionFactory) throws UnknownHostException { StringRedisTemplate template = new StringRedisTemplate(); template.setConnectionFactory(redisConnectionFactory); return template; } }
至此 Redis 在 SpringBoot 項(xiàng)目中的配置已經(jīng)完成,可以愉快的使用了。 1.3 Redis 的數(shù)據(jù)結(jié)構(gòu)類型Redis 可以存儲(chǔ)鍵與5種不同數(shù)據(jù)結(jié)構(gòu)類型之間的映射,這5種數(shù)據(jù)結(jié)構(gòu)類型分別為String(字符串)、List(列表)、Set(集合)、Hash(散列)和 Zset(有序集合)。 下面來對(duì)這5種數(shù)據(jù)結(jié)構(gòu)類型作簡(jiǎn)單的介紹: 
1.4 點(diǎn)贊數(shù)據(jù)在 Redis 中的存儲(chǔ)格式用 Redis 存儲(chǔ)兩種數(shù)據(jù),一種是記錄點(diǎn)贊人、被點(diǎn)贊人、點(diǎn)贊狀態(tài)的數(shù)據(jù),另一種是每個(gè)用戶被點(diǎn)贊了多少次,做個(gè)簡(jiǎn)單的計(jì)數(shù)。 由于需要記錄點(diǎn)贊人和被點(diǎn)贊人,還有點(diǎn)贊狀態(tài)(點(diǎn)贊、取消點(diǎn)贊),還要固定時(shí)間間隔取出 Redis 中所有點(diǎn)贊數(shù)據(jù),分析了下 Redis 數(shù)據(jù)格式中 Hash 最合適。 因?yàn)?Hash 里的數(shù)據(jù)都是存在一個(gè)鍵里,可以通過這個(gè)鍵很方便的把所有的點(diǎn)贊數(shù)據(jù)都取出。這個(gè)鍵里面的數(shù)據(jù)還可以存成鍵值對(duì)的形式,方便存入點(diǎn)贊人、被點(diǎn)贊人和點(diǎn)贊狀態(tài)。 設(shè)點(diǎn)贊人的 id 為 likedPostId,被點(diǎn)贊人的 id 為 likedUserId ,點(diǎn)贊時(shí)狀態(tài)為 1,取消點(diǎn)贊狀態(tài)為 0。將點(diǎn)贊人 id 和被點(diǎn)贊人 id 作為鍵,兩個(gè) id 中間用 :: 隔開,點(diǎn)贊狀態(tài)作為值。 所以如果用戶點(diǎn)贊,存儲(chǔ)的鍵為:likedUserId::likedPostId,對(duì)應(yīng)的值為 1 。取消點(diǎn)贊,存儲(chǔ)的鍵為:likedUserId::likedPostId,對(duì)應(yīng)的值為 0 。取數(shù)據(jù)時(shí)把鍵用 :: 切開就得到了兩個(gè)id,也很方便。 在可視化工具 RDM 中看到的是這樣子 

1.5 操作 Redis將具體操作方法封裝到了 RedisService 接口里 RedisService.java import com.solo.coderiver.user.dataobject.UserLike; import com.solo.coderiver.user.dto.LikedCountDTO;
import java.util.List;
public interface RedisService {
/** * 點(diǎn)贊。狀態(tài)為1 * @param likedUserId * @param likedPostId */ void saveLiked2Redis(String likedUserId, String likedPostId);
/** * 取消點(diǎn)贊。將狀態(tài)改變?yōu)? * @param likedUserId * @param likedPostId */ void unlikeFromRedis(String likedUserId, String likedPostId);
/** * 從Redis中刪除一條點(diǎn)贊數(shù)據(jù) * @param likedUserId * @param likedPostId */ void deleteLikedFromRedis(String likedUserId, String likedPostId);
/** * 該用戶的點(diǎn)贊數(shù)加1 * @param likedUserId */ void incrementLikedCount(String likedUserId);
/** * 該用戶的點(diǎn)贊數(shù)減1 * @param likedUserId */ void decrementLikedCount(String likedUserId);
/** * 獲取Redis中存儲(chǔ)的所有點(diǎn)贊數(shù)據(jù) * @return */ List<UserLike> getLikedDataFromRedis();
/** * 獲取Redis中存儲(chǔ)的所有點(diǎn)贊數(shù)量 * @return */ List<LikedCountDTO> getLikedCountFromRedis();
}
實(shí)現(xiàn)類 RedisServiceImpl.java import com.solo.coderiver.user.dataobject.UserLike; import com.solo.coderiver.user.dto.LikedCountDTO; import com.solo.coderiver.user.enums.LikedStatusEnum; import com.solo.coderiver.user.service.LikedService; import com.solo.coderiver.user.service.RedisService; import com.solo.coderiver.user.utils.RedisKeyUtils; import lombok.extern.slf4j.Slf4j; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.redis.core.Cursor; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.core.ScanOptions; import org.springframework.stereotype.Service;
import java.util.ArrayList; import java.util.List; import java.util.Map;
@Service @Slf4j public class RedisServiceImpl implements RedisService {
@Autowired RedisTemplate redisTemplate;
@Autowired LikedService likedService;
@Override public void saveLiked2Redis(String likedUserId, String likedPostId) { String key = RedisKeyUtils.getLikedKey(likedUserId, likedPostId); redisTemplate.opsForHash().put(RedisKeyUtils.MAP_KEY_USER_LIKED, key, LikedStatusEnum.LIKE.getCode()); }
@Override public void unlikeFromRedis(String likedUserId, String likedPostId) { String key = RedisKeyUtils.getLikedKey(likedUserId, likedPostId); redisTemplate.opsForHash().put(RedisKeyUtils.MAP_KEY_USER_LIKED, key, LikedStatusEnum.UNLIKE.getCode()); }
@Override public void deleteLikedFromRedis(String likedUserId, String likedPostId) { String key = RedisKeyUtils.getLikedKey(likedUserId, likedPostId); redisTemplate.opsForHash().delete(RedisKeyUtils.MAP_KEY_USER_LIKED, key); }
@Override public void incrementLikedCount(String likedUserId) { redisTemplate.opsForHash().increment(RedisKeyUtils.MAP_KEY_USER_LIKED_COUNT, likedUserId, 1); }
@Override public void decrementLikedCount(String likedUserId) { redisTemplate.opsForHash().increment(RedisKeyUtils.MAP_KEY_USER_LIKED_COUNT, likedUserId, -1); }
@Override public List<UserLike> getLikedDataFromRedis() { Cursor<Map.Entry<Object, Object>> cursor = redisTemplate.opsForHash().scan(RedisKeyUtils.MAP_KEY_USER_LIKED, ScanOptions.NONE); List<UserLike> list = new ArrayList<>(); while (cursor.hasNext()){ Map.Entry<Object, Object> entry = cursor.next(); String key = (String) entry.getKey(); //分離出 likedUserId,likedPostId String[] split = key.split('::'); String likedUserId = split[0]; String likedPostId = split[1]; Integer value = (Integer) entry.getValue();
//組裝成 UserLike 對(duì)象 UserLike userLike = new UserLike(likedUserId, likedPostId, value); list.add(userLike);
//存到 list 后從 Redis 中刪除 redisTemplate.opsForHash().delete(RedisKeyUtils.MAP_KEY_USER_LIKED, key); }
return list; }
@Override public List<LikedCountDTO> getLikedCountFromRedis() { Cursor<Map.Entry<Object, Object>> cursor = redisTemplate.opsForHash().scan(RedisKeyUtils.MAP_KEY_USER_LIKED_COUNT, ScanOptions.NONE); List<LikedCountDTO> list = new ArrayList<>(); while (cursor.hasNext()){ Map.Entry<Object, Object> map = cursor.next(); //將點(diǎn)贊數(shù)量存儲(chǔ)在 LikedCountDT String key = (String)map.getKey(); LikedCountDTO dto = new LikedCountDTO(key, (Integer) map.getValue()); list.add(dto); //從Redis中刪除這條記錄 redisTemplate.opsForHash().delete(RedisKeyUtils.MAP_KEY_USER_LIKED_COUNT, key); } return list; } }
用到的工具類和枚舉類 RedisKeyUtils, 用于根據(jù)一定規(guī)則生成 key public class RedisKeyUtils {
//保存用戶點(diǎn)贊數(shù)據(jù)的key public static final String MAP_KEY_USER_LIKED = 'MAP_USER_LIKED'; //保存用戶被點(diǎn)贊數(shù)量的key public static final String MAP_KEY_USER_LIKED_COUNT = 'MAP_USER_LIKED_COUNT';
/** * 拼接被點(diǎn)贊的用戶id和點(diǎn)贊的人的id作為key。格式 222222::333333 * @param likedUserId 被點(diǎn)贊的人id * @param likedPostId 點(diǎn)贊的人的id * @return */ public static String getLikedKey(String likedUserId, String likedPostId){ StringBuilder builder = new StringBuilder(); builder.append(likedUserId); builder.append('::'); builder.append(likedPostId); return builder.toString(); } }
LikedStatusEnum 用戶點(diǎn)贊狀態(tài)的枚舉類 package com.solo.coderiver.user.enums;
import lombok.Getter;
/** * 用戶點(diǎn)贊的狀態(tài) */ @Getter public enum LikedStatusEnum { LIKE(1, '點(diǎn)贊'), UNLIKE(0, '取消點(diǎn)贊/未點(diǎn)贊'), ;
private Integer code;
private String msg;
LikedStatusEnum(Integer code, String msg) { this.code = code; this.msg = msg; } }
二、數(shù)據(jù)庫設(shè)計(jì)數(shù)據(jù)庫表中至少要包含三個(gè)字段:被點(diǎn)贊用戶id,點(diǎn)贊用戶id,點(diǎn)贊狀態(tài)。再加上主鍵id,創(chuàng)建時(shí)間,修改時(shí)間就行了。 建表語句 create table `user_like`( `id` int not null auto_increment, `liked_user_id` varchar(32) not null comment '被點(diǎn)贊的用戶id', `liked_post_id` varchar(32) not null comment '點(diǎn)贊的用戶id', `status` tinyint(1) default '1' comment '點(diǎn)贊狀態(tài),0取消,1點(diǎn)贊', `create_time` timestamp not null default current_timestamp comment '創(chuàng)建時(shí)間', `update_time` timestamp not null default current_timestamp on update current_timestamp comment '修改時(shí)間', primary key(`id`), INDEX `liked_user_id`(`liked_user_id`), INDEX `liked_post_id`(`liked_post_id`) ) comment '用戶點(diǎn)贊表';
對(duì)應(yīng)的對(duì)象 UserLike import com.solo.coderiver.user.enums.LikedStatusEnum; import lombok.Data;
import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id;
/** * 用戶點(diǎn)贊表 */ @Entity @Data public class UserLike {
//主鍵id @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Integer id;
//被點(diǎn)贊的用戶的id private String likedUserId;
//點(diǎn)贊的用戶的id private String likedPostId;
//點(diǎn)贊的狀態(tài).默認(rèn)未點(diǎn)贊 private Integer status = LikedStatusEnum.UNLIKE.getCode();
public UserLike() { }
public UserLike(String likedUserId, String likedPostId, Integer status) { this.likedUserId = likedUserId; this.likedPostId = likedPostId; this.status = status; } }
三、數(shù)據(jù)庫操作操作數(shù)據(jù)庫同樣封裝在接口中 LikedService import com.solo.coderiver.user.dataobject.UserLike; import org.springframework.data.domain.Page; import org.springframework.data.domain.Pageable;
import java.util.List;
public interface LikedService {
/** * 保存點(diǎn)贊記錄 * @param userLike * @return */ UserLike save(UserLike userLike);
/** * 批量保存或修改 * @param list */ List<UserLike> saveAll(List<UserLike> list);
/** * 根據(jù)被點(diǎn)贊人的id查詢點(diǎn)贊列表(即查詢都誰給這個(gè)人點(diǎn)贊過) * @param likedUserId 被點(diǎn)贊人的id * @param pageable * @return */ Page<UserLike> getLikedListByLikedUserId(String likedUserId, Pageable pageable);
/** * 根據(jù)點(diǎn)贊人的id查詢點(diǎn)贊列表(即查詢這個(gè)人都給誰點(diǎn)贊過) * @param likedPostId * @param pageable * @return */ Page<UserLike> getLikedListByLikedPostId(String likedPostId, Pageable pageable);
/** * 通過被點(diǎn)贊人和點(diǎn)贊人id查詢是否存在點(diǎn)贊記錄 * @param likedUserId * @param likedPostId * @return */ UserLike getByLikedUserIdAndLikedPostId(String likedUserId, String likedPostId);
/** * 將Redis里的點(diǎn)贊數(shù)據(jù)存入數(shù)據(jù)庫中 */ void transLikedFromRedis2DB();
/** * 將Redis中的點(diǎn)贊數(shù)量數(shù)據(jù)存入數(shù)據(jù)庫 */ void transLikedCountFromRedis2DB();
}
LikedServiceImpl 實(shí)現(xiàn)類 import com.solo.coderiver.user.dataobject.UserInfo; import com.solo.coderiver.user.dataobject.UserLike; import com.solo.coderiver.user.dto.LikedCountDTO; import com.solo.coderiver.user.enums.LikedStatusEnum; import com.solo.coderiver.user.repository.UserLikeRepository; import com.solo.coderiver.user.service.LikedService; import com.solo.coderiver.user.service.RedisService; import com.solo.coderiver.user.service.UserService; import lombok.extern.slf4j.Slf4j; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.domain.Page; import org.springframework.data.domain.Pageable; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional;
import java.util.List;
@Service @Slf4j public class LikedServiceImpl implements LikedService {
@Autowired UserLikeRepository likeRepository;
@Autowired RedisService redisService;
@Autowired UserService userService;
@Override @Transactional public UserLike save(UserLike userLike) { return likeRepository.save(userLike); }
@Override @Transactional public List<UserLike> saveAll(List<UserLike> list) { return likeRepository.saveAll(list); }
@Override public Page<UserLike> getLikedListByLikedUserId(String likedUserId, Pageable pageable) { return likeRepository.findByLikedUserIdAndStatus(likedUserId, LikedStatusEnum.LIKE.getCode(), pageable); }
@Override public Page<UserLike> getLikedListByLikedPostId(String likedPostId, Pageable pageable) { return likeRepository.findByLikedPostIdAndStatus(likedPostId, LikedStatusEnum.LIKE.getCode(), pageable); }
@Override public UserLike getByLikedUserIdAndLikedPostId(String likedUserId, String likedPostId) { return likeRepository.findByLikedUserIdAndLikedPostId(likedUserId, likedPostId); }
@Override @Transactional public void transLikedFromRedis2DB() { List<UserLike> list = redisService.getLikedDataFromRedis(); for (UserLike like : list) { UserLike ul = getByLikedUserIdAndLikedPostId(like.getLikedUserId(), like.getLikedPostId()); if (ul == null){ //沒有記錄,直接存入 save(like); }else{ //有記錄,需要更新 ul.setStatus(like.getStatus()); save(ul); } } }
@Override @Transactional public void transLikedCountFromRedis2DB() { List<LikedCountDTO> list = redisService.getLikedCountFromRedis(); for (LikedCountDTO dto : list) { UserInfo user = userService.findById(dto.getId()); //點(diǎn)贊數(shù)量屬于無關(guān)緊要的操作,出錯(cuò)無需拋異常 if (user != null){ Integer likeNum = user.getLikeNum() + dto.getCount(); user.setLikeNum(likeNum); //更新點(diǎn)贊數(shù)量 userService.updateInfo(user); } } } }
數(shù)據(jù)庫的操作就這些,主要還是增刪改查。 四、開啟定時(shí)任務(wù)持久化存儲(chǔ)到數(shù)據(jù)庫定時(shí)任務(wù) Quartz 很強(qiáng)大,就用它了。 Quartz 使用步驟: 1.添加依賴 <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-quartz</artifactId> </dependency>
2.編寫配置文件 package com.solo.coderiver.user.config;
import com.solo.coderiver.user.task.LikeTask; import org.quartz.*; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration;
@Configuration public class QuartzConfig {
private static final String LIKE_TASK_IDENTITY = 'LikeTaskQuartz';
@Bean public JobDetail quartzDetail(){ return JobBuilder.newJob(LikeTask.class).withIdentity(LIKE_TASK_IDENTITY).storeDurably().build(); }
@Bean public Trigger quartzTrigger(){ SimpleScheduleBuilder scheduleBuilder = SimpleScheduleBuilder.simpleSchedule() // .withIntervalInSeconds(10) //設(shè)置時(shí)間周期單位秒 .withIntervalInHours(2) //兩個(gè)小時(shí)執(zhí)行一次 .repeatForever(); return TriggerBuilder.newTrigger().forJob(quartzDetail()) .withIdentity(LIKE_TASK_IDENTITY) .withSchedule(scheduleBuilder) .build(); } }
3.編寫執(zhí)行任務(wù)的類繼承自 QuartzJobBean package com.solo.coderiver.user.task;
import com.solo.coderiver.user.service.LikedService; import lombok.extern.slf4j.Slf4j; import org.apache.commons.lang.time.DateUtils; import org.quartz.JobExecutionContext; import org.quartz.JobExecutionException; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.scheduling.quartz.QuartzJobBean;
import java.text.SimpleDateFormat; import java.util.Date;
/** * 點(diǎn)贊的定時(shí)任務(wù) */ @Slf4j public class LikeTask extends QuartzJobBean {
@Autowired LikedService likedService;
private SimpleDateFormat sdf = new SimpleDateFormat('yyyy-MM-dd HH:mm:ss');
@Override protected void executeInternal(JobExecutionContext jobExecutionContext) throws JobExecutionException {
log.info('LikeTask-------- {}', sdf.format(new Date()));
//將 Redis 里的點(diǎn)贊信息同步到數(shù)據(jù)庫里 likedService.transLikedFromRedis2DB(); likedService.transLikedCountFromRedis2DB(); } }
在定時(shí)任務(wù)中直接調(diào)用 LikedService 封裝的方法完成數(shù)據(jù)同步。 以上就是點(diǎn)贊功能的設(shè)計(jì)與實(shí)現(xiàn),不足之處還請(qǐng)各位大佬多多指教。 另外,點(diǎn)贊/取消點(diǎn)贊 跟 點(diǎn)贊數(shù) +1/ -1 應(yīng)該保證是原子操作 , 不然出現(xiàn)并發(fā)問題就會(huì)有兩條重復(fù)的點(diǎn)贊記錄 , 所以要給整個(gè)原子操作加鎖 . 同時(shí)需要在Spring Boot 的系統(tǒng)關(guān)閉鉤子函數(shù)中補(bǔ)充同步redis中點(diǎn)贊數(shù)據(jù)到mysql中的過程 . 不然有可能出現(xiàn)距離上一次同步1小時(shí)59分的時(shí)候服務(wù)器更新 , 把整整兩小時(shí)的點(diǎn)贊數(shù)據(jù)都給清空了 . 如果點(diǎn)贊設(shè)計(jì)到比較重要活動(dòng)業(yè)務(wù)的話這就很尷尬了 . 如有更好的實(shí)現(xiàn)方案歡迎在評(píng)論區(qū)交流… 代碼出自開源項(xiàng)目 CodeRiver,歡迎圍觀: https://github.com/cachecats/coderiver
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