Redis(案例二：高并发商品首页热点数据开发实战)

热点数据

经常会被查询，但是不经常被修改或者删除的数据
⾸⻚-详情⻚

链路逻辑

检查缓存是否有
缓存不存在则查询数据库
查询结果放到缓存，设置过期时间
下次访问则命中缓存

代码实现

pojo —热点视频

@Data
@NoArgsConstructor
@AllArgsConstructor
public class VideoDO {private int id;private String title;private String img;private int price;

pojo —热点卡片

@Data
import java.util.List;public class VideoCardDO {private String title;private int id;private int weight;List<VideoDO> list;

dao —模拟数据

import net.xdclass.xdclassredis.model.VideoCardDO;
import net.xdclass.xdclassredis.model.VideoDO;
import org.springframework.stereotype.Repository;import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;@Repository
public class VideoCardDao {public List<VideoCardDO> list(){try {TimeUnit.MILLISECONDS.sleep(200);} catch (InterruptedException e) {e.printStackTrace();}List<VideoCardDO> cardDOList = new ArrayList<>();VideoCardDO videoCardDO = new VideoCardDO();videoCardDO.setId(1);videoCardDO.setTitle("热门视频");VideoDO videoDO1 = new VideoDO(1,"springcloud微服务视频","xdclass.net",43);VideoDO videoDO2 = new VideoDO(2,"Paas工业级项目实战","xdclass.net",32);VideoDO videoDO3 = new VideoDO(3,"面试专题视频","xdclass.net",43);VideoDO videoDO4 = new VideoDO(4,"spring源码实战","xdclass.net",4);List<VideoDO> videoDOS = new ArrayList<>();videoDOS.add(videoDO1);videoDOS.add(videoDO2);videoDOS.add(videoDO3);videoDOS.add(videoDO4);videoCardDO.setList(videoDOS);VideoCardDO videoCardDO2 = new VideoCardDO();videoCardDO2.setId(2);videoCardDO2.setTitle("项目实战视频");VideoDO videoDO5 = new VideoDO(1,"springcloud微服务视频项目","xdclass.net",43);VideoDO videoDO6 = new VideoDO(2,"Paas工业级项目实战项目","xdclass.net",32);VideoDO videoDO7 = new VideoDO(3,"面试专题视频项目","xdclass.net",43);VideoDO videoDO8 = new VideoDO(4,"设计模式视频","xdclass.net",4);List<VideoDO> videoDOS2 = new ArrayList<>();videoDOS2.add(videoDO5);videoDOS2.add(videoDO6);videoDOS2.add(videoDO7);videoDOS2.add(videoDO8);videoCardDO2.setList(videoDOS2);cardDOList.add(videoCardDO);cardDOList.add(videoCardDO2);return cardDOList;}}

service

import net.xdclass.xdclassredis.model.VideoCardDO;
import java.util.List;public interface VideoCardService {List<VideoCardDO> list();
}

serviceImpl

import net.xdclass.xdclassredis.dao.VideoCardDao;
import net.xdclass.xdclassredis.model.VideoCardDO;
import net.xdclass.xdclassredis.service.VideoCardService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;import java.util.List;@Service
public class VideoCardServiceImpl implements VideoCardService {@Autowiredprivate VideoCardDao videoCardDao;@Overridepublic List<VideoCardDO> list() {return videoCardDao.list();}
}

controller

import net.xdclass.xdclassredis.model.VideoCardDO;
import net.xdclass.xdclassredis.service.VideoCardService;
import net.xdclass.xdclassredis.util.JsonData;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;import java.util.List;
import java.util.concurrent.TimeUnit;@RequestMapping("/api/v1/card")
@RestController
public class VideoCardController {@Autowiredprivate VideoCardService videoCardService;@Autowiredprivate RedisTemplate redisTemplate;/*** 缓存key*/private static final String VIDEO_CARD_CACHE_KEY = "video:card:key";/*** 有缓存* @return*/@GetMapping("list_cache")public JsonData listCardCache(){Object cacheObj = redisTemplate.opsForValue().get(VIDEO_CARD_CACHE_KEY);if(cacheObj != null){List<VideoCardDO> list = (List<VideoCardDO>) cacheObj;return JsonData.buildSuccess(list);} else {List<VideoCardDO> list = videoCardService.list();redisTemplate.opsForValue().set(VIDEO_CARD_CACHE_KEY,list,10,TimeUnit.MINUTES);return JsonData.buildSuccess(list);}}/*** 无缓存* @return*/@GetMapping("list_nocache")public JsonData listCardNoCache(){List<VideoCardDO> list = videoCardService.list();return JsonData.buildSuccess(list);}}