Springboot 使用Redis中ZSetOperations实现博客访问量功能

1.在application.yml中Redis配置信息

spring:redis:host: 127.0.0.1port: 6379password: 12345678

2.在pom.xml中加载依赖

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

3.配置Redis Template

@Configuration
public class RedisConfig {@Bean("redisTemplate")public RedisTemplate<String, Object> redisTemplate(LettuceConnectionFactory lettuceConnectionFactory) {// 1.创建RedisTemplate对象RedisTemplate<String, Object> redisTemplate = new RedisTemplate<String, Object>();// 2.加载Redis配置redisTemplate.setConnectionFactory(lettuceConnectionFactory);// 3.配置key序列化RedisSerializer<?> stringRedisSerializer = new StringRedisSerializer();redisTemplate.setKeySerializer(stringRedisSerializer);redisTemplate.setHashKeySerializer(stringRedisSerializer);// 4.配置Value序列化Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer<Object>(Object.class);ObjectMapper objMapper = new ObjectMapper();objMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);objMapper.activateDefaultTyping(objMapper.getPolymorphicTypeValidator(), ObjectMapper.DefaultTyping.NON_FINAL);jackson2JsonRedisSerializer.setObjectMapper(objMapper);redisTemplate.setValueSerializer(jackson2JsonRedisSerializer);redisTemplate.setHashValueSerializer(jackson2JsonRedisSerializer);// 5.初始化RedisTemplateredisTemplate.afterPropertiesSet();return redisTemplate;}@Beanpublic ZSetOperations<String, Object> zSetOperations(RedisTemplate<String, Object> redisTemplate) {return redisTemplate.opsForZSet();}
}

4.操作说明

在Spring环境中，可以@Autowired自动注入方式注入操作Redis对象。比如：RedisTemplate、ZSetOperations。

 @Autowiredprivate RedisTemplate redisTemplate;@Autowiredprivate ZSetOperations zSetOperations;

更新浏览量(不用去更新到mysql了)

     //这个完全采用redis设计就可以 不用查询数据库 把阅读量完全加入到缓存中  public void updateReadCount(Integer blogId) {zSetOperations.incrementScore(BLOG_KEY, blogId, 1);//blogMapper.updateReadCount(blogId); 不用在mysql数据库更新了}

取出榜单TopK(效率提高不用在数据库中查出所有的然后取前20)

    public List<Blog> selectTop() {List<Blog> blogList = new ArrayList<>();Long size = zSetOperations.size(BLOG_KEY);Set<Object> zset;if(size > TopN){zset = zSetOperations.reverseRange(BLOG_KEY, 0, TopN - 1);}else{zset = zSetOperations.reverseRange(BLOG_KEY, 0, - 1);}for(Object x:zset){blogList.add(blogMapper.selectById((int)x));}return blogList;}

显示浏览量(直接设定到mysql属性就好)

        Double score = zSetOperations.score(BLOG_KEY, blog.getId());int readCount = (score != null) ? score.intValue() : 0;blog.setReadCount(readCount);