SpringBoot2.x 整合Redis实现缓存，自定义序列化和设置过期时间

言曌 2019年01月18日22:24:08 6 21420 views

博主分享免费Java教学视频，B站账号：Java刘哥

SpringBoot2.x和1.x的区别很大，比如在整合 Redis 这一块，RedisCacheManager就有不同。本文介绍 SpringBoot 2.0.5版本整合 Redis。

一、基本配置

pom.xml

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

2.RedisConfig.java

package com.liuyanzhao.sens.config;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.*;
import java.time.Duration;
/**
* @author 言曌
* @date 2018/5/21 上午10:02
*/
@Configuration
@EnableCaching
@Slf4j
public class RedisConfig {
//过期时间1天
private Duration timeToLive = Duration.ofDays(1);
@Bean
public RedisCacheManager cacheManager(RedisConnectionFactory connectionFactory) {
//默认1
RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
.entryTtl(this.timeToLive)
.serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(keySerializer()))
.serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(valueSerializer()))
.disableCachingNullValues();
RedisCacheManager redisCacheManager = RedisCacheManager.builder(connectionFactory)
.cacheDefaults(config)
.transactionAware()
.build();
log.debug("自定义RedisCacheManager加载完成");
return redisCacheManager;
}
@Bean(name = "redisTemplate")
public RedisTemplate<String,Object> redisTemplate(RedisConnectionFactory redisConnectionFactory){
RedisTemplate<String,Object> redisTemplate = new RedisTemplate<>();
redisTemplate.setConnectionFactory(redisConnectionFactory);
redisTemplate.setKeySerializer(keySerializer());
redisTemplate.setHashKeySerializer(keySerializer());
redisTemplate.setValueSerializer(valueSerializer());
redisTemplate.setHashValueSerializer(valueSerializer());
log.debug("自定义RedisTemplate加载完成");
return redisTemplate;
}
private RedisSerializer<String> keySerializer() {
return new StringRedisSerializer();
}
private RedisSerializer<Object> valueSerializer() {
return new GenericJackson2JsonRedisSerializer();
}
}

设置默认过期时间1天 GenericJackson2JsonRedisSerializer序列化value是采用json格式，里面有对象的class名称，便于反序列化。

二、@Cacheable和@CacheEvict 的使用

以友情链接的service实现为例

package com.liuyanzhao.sens.service.impl;
import com.liuyanzhao.sens.entity.Link;
import com.liuyanzhao.sens.mapper.LinkMapper;
import com.liuyanzhao.sens.service.LinkService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;
import java.util.List;
/**
* <pre>
* 友情链接业务逻辑实现类
* </pre>
*
* @author : saysky
* @date : 2017/11/14
*/
@Service
public class LinkServiceImpl implements LinkService {
private static final String LINKS_CACHE_NAME = "links";
@Autowired(required = false)
private LinkMapper linkMapper;
@Override
@CacheEvict(value = LINKS_CACHE_NAME, allEntries = true, beforeInvocation = true)
public Link saveByLink(Link link) {
if (link != null && link.getLinkId() != null) {
linkMapper.updateById(link);
} else {
linkMapper.insert(link);
}
return link;
}
@Override
@CacheEvict(value = LINKS_CACHE_NAME, allEntries = true, beforeInvocation = true)
public void removeByLinkId(Long linkId) {
linkMapper.deleteById(linkId);
}
@Override
@Cacheable(value = LINKS_CACHE_NAME, key = "'links_all'")
public List<Link> findAllLinks() {
return linkMapper.findAll();
}
@Override
@Cacheable(value = LINKS_CACHE_NAME, key = "'links_id_'+#linkId", unless = "#result == null")
public Link findByLinkId(Long linkId) {
return linkMapper.selectById(linkId);
}
@Override
@Cacheable(value = LINKS_CACHE_NAME, key = "'links_count'")
public Integer getCount() {
return linkMapper.selectCount(null);
}
}

除了 @Cacheable、@CacheEvict之外，还有@CachePut，一般不用查询一律用 @Cacheable，先从 Redis 查有没有这个 key，如果没有则执行方法里的代码，从数据库查询，并将结果存到 Redis 中。 @CacheEvict 可以指定删除某个 key，也可以删除 value 集合的所有 key。