使用@Cacheable设置缓存的过期时间

时间:2022-05-23 Qiwany 人气:79

使用@Cacheable时设置部分缓存的过期时间

业务场景

Spring Boot项目中有一些查询数据需要缓存到Redis中，其中有一些缓存是固定数据不会改变，那么就没必要设置过期时间。还有一些缓存需要每隔几分钟就更新一次，这时就需要设置过期时间。

Service层部分代码如下：

@Override
@Cacheable(cacheNames = {"distributor"}, key = "#root.methodName")
public List<CityVO> findCities() {
 return distributorMapper.selectCities();
}
@Override
@Cacheable(cacheNames = {"distributor"}, key = "#root.methodName.concat('#cityId').concat(#cityId)")
public List<DistributorVO> findDistributorsByCityId(String cityId) {
 return distributorMapper.selectByCityId(cityId);
}

@Override
@Cacheable(cacheNames = {"car"}, key = "#root.methodName.concat('#cityId').concat(#cityId)")
public String carList(String cityId) {
 RequestData data = new RequestData();
 data.setCityId(cityId);
 
 CarListParam param = new CarListParam();
 param.setRequestData(data);
 
 String jsonParam = JSON.toJSONString(param);
 return HttpClientUtil.sendPostWithJson(ApiUrlConst.MULE_APP, jsonParam);
}

在使用@Cacheable注解对查询数据进行缓存时，使用cacheNames属性指定了缓存名称。下面我们就针对不同的cacheNames来设置失效时间。

添加Redis配置类RedisConfig.java

代码如下：

@Slf4j
@Configuration
@EnableCaching //启用缓存
public class RedisConfig {
 
 /**
  * 自定义缓存管理器
  */
 @Bean
 public RedisCacheManager cacheManager(RedisConnectionFactory factory) {
  RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig();
  Set<String> cacheNames = new HashSet<>();
  cacheNames.add("car");
  cacheNames.add("distributor");
  ConcurrentHashMap<String, RedisCacheConfiguration> configMap = new ConcurrentHashMap<>();
  configMap.put("car", config.entryTtl(Duration.ofMinutes(6L)));
  configMap.put("distributor", config);
  
  //需要先初始化缓存名称，再初始化其它的配置。
  RedisCacheManager cacheManager = RedisCacheManager.builder(factory).initialCacheNames(cacheNames).withInitialCacheConfigurations(configMap).build();
  return cacheManager;
 }
}

上面代码，在configMap中指定了cacheNames为car的缓存过期时间为6分钟。

@Cacheable自定义缓存过期时间

pom

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-pool2</artifactId>
</dependency>

yml

#  redis配置
spring:
    redis:
      database: 0
      host: 127.0.0.1
      password: 123456
      port: 6379
      timeout:  5000
      lettuce:
        pool:
          max-active: 300
          max-wait: -1
          max-idle: 20
          min-idle: 10

RedisConfig

RedisCacheManager：缓存默认不过期，所以这里返回自定RedisCacheManager

//return new RedisCacheManager(redisCacheWriter, redisCacheConfiguration);
return new CustomRedisCacheManager(redisCacheWriter, redisCacheConfiguration);

@Configuration
public class RedisConfig {
    
    /*
     * @description redis序列化方式
     * @author xianping
     * @date 2020/9/25
     * @param redisConnectionFactory
     * @return RedisTemplate
     **/
    @Bean
    public RedisTemplate redisTemplate(RedisConnectionFactory redisConnectionFactory) {
        RedisTemplate redisTemplate = new RedisTemplate();
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(objectMapper);
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(jackson2JsonRedisSerializer);
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        redisTemplate.setHashValueSerializer(jackson2JsonRedisSerializer);
        redisTemplate.afterPropertiesSet();
        return redisTemplate;
    }
    /*
     * @description Redis缓存的序列化方式使用redisTemplate.getValueSerializer()，不在使用JDK默认的序列化方式
     * @author xianping
     * @date 2020/9/25
     * @param redisTemplate
     * @return RedisCacheManager
     **/
    @Bean
    public RedisCacheManager redisCacheManager(RedisTemplate redisTemplate) {
        RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(redisTemplate.getConnectionFactory());
        RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()               
        .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(redisTemplate.getValueSerializer()));
        //return new RedisCacheManager(redisCacheWriter, redisCacheConfiguration);
        return new CustomRedisCacheManager(redisCacheWriter, redisCacheConfiguration);
    }
}

CustomRedisCacheManager

自定义RedisCacheManager：若@Cacheable value中包含'#‘号，则'#'后为缓存生存时间，不存在则表示缓存不进行生存时间设置

//cacheConfig.entryTtl 设置缓存过期时间
public RedisCacheConfiguration entryTtl(Duration ttl) {
    Assert.notNull(ttl, "TTL duration must not be null!");
    return new RedisCacheConfiguration(ttl, this.cacheNullValues, this.usePrefix,    this.keyPrefix, this.keySerializationPair, this.valueSerializationPair,     this.conversionService);
}

//Duration.ofMinutes 持续时间
//这里默认是以分钟为单位，所以调用ofMinutes静态方法进行转换
public static Duration ofMinutes(long minutes) {
        return create(Math.multiplyExact(minutes, SECONDS_PER_MINUTE), 0);
}

public class CustomRedisCacheManager extends RedisCacheManager {
    /*
     * @description 提供默认构造器
     * @author xianping
     * @date 2020/9/28 9:22
     * @param
     * @param cacheWriter
     * @param defaultCacheConfiguration
     * @return
     **/
    public CustomRedisCacheManager(RedisCacheWriter cacheWriter, RedisCacheConfiguration defaultCacheConfiguration) {
        super(cacheWriter, defaultCacheConfiguration);
    }
    /*
     * @description 重写父类createRedisCache方法
     * @author xianping
     * @date 2020/9/28 9:22
     * @param
     * @param name @Cacheable中的value
     * @param cacheConfig
     * @return org.springframework.data.redis.cache.RedisCache
     **/
    @Override
    protected RedisCache createRedisCache(String name, RedisCacheConfiguration cacheConfig) {
        //名称中存在#标记进行到期时间配置
        if (!name.isEmpty() && name.contains("#")) {
            String[] SPEL = name.split("#");
            if (StringUtils.isNumeric(SPEL[1])) {
                //配置缓存到期时间
                int cycle = Integer.parseInt(SPEL[1]);
                return super.createRedisCache(SPEL[0], cacheConfig.entryTtl(Duration.ofMinutes(cycle * 24 * 60)));
            }
        }
        return super.createRedisCache(name, cacheConfig);
    }
}

使用

生存时间1天

@Cacheable(value = "cacheTest#1")
public String cacheTest() {
    return "cacheTest";
}

缓存持久，无过期时间

@Cacheable(value = "cacheTest")
public String cacheTest() {
    return "cacheTest";
}

以上为个人经验，希望能给大家一个参考，也希望大家多多支持。

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