@Cacheable的使用，及设置过期时间 配置方式

所需依赖

		
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-cacheartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-data-redisartifactId>
        dependency>
        
        <dependency>
            <groupId>org.apache.commonsgroupId>
            <artifactId>commons-lang3artifactId>
            <version>3.8.1version>
        dependency>

yml -文件

spring:
# Redis configuration
  redis:
    host: ${REDIS_HOST:127.0.0.1}
    port: ${REDIS_PORT:6379}
    password: ${REDIS_PWD:}
    #默认使用db2
    database: ${REDIS_DB_NO:12}

CacheConfig – 注解配置类

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.cache.CacheManager;
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.RedisCacheWriter;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
 
import java.time.Duration;

@EnableCaching
@Configuration
public class CacheConfig {
 
    @Bean
    public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory) {
 
        ObjectMapper om = new ObjectMapper();
        RedisSerializer<String> redisSerializer = new StringRedisSerializer();
        Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer<>(
                Object.class);
        // 解决查询缓存转换异常的问题
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        // 配置序列化（解决乱码的问题）
        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofMillis(-1))
                .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer))
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer))
                .disableCachingNullValues();
        RedisCacheWriter cacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(redisConnectionFactory);
 
        return new RedisConfigCacheManager(cacheWriter, config);
 
    }
 
}

RedisConfigCacheManager - redis 配置类

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.data.redis.cache.*;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;

import java.time.Duration;
 
/**
 * redis 配置类
 */
@Slf4j
public class RedisConfigCacheManager extends RedisCacheManager {
 
 
    public RedisConfigCacheManager(RedisCacheWriter cacheWriter, RedisCacheConfiguration defaultCacheConfiguration) {
        super(cacheWriter, defaultCacheConfiguration);
    }
 
    private static final RedisSerializationContext.SerializationPair<Object> DEFAULT_PAIR = RedisSerializationContext.SerializationPair
            .fromSerializer(new GenericJackson2JsonRedisSerializer());
 
    private static final CacheKeyPrefix DEFAULT_CACHE_KEY_PREFIX = cacheName -> cacheName+":";
 
    @Override
    protected RedisCache createRedisCache(String name, RedisCacheConfiguration cacheConfig) {
        final int lastIndexOf = StringUtils.lastIndexOf(name, '#');
        if (lastIndexOf > -1) {
            final String time = StringUtils.substring(name, lastIndexOf + 1);
            final Duration duration = Duration.ofSeconds(Long.parseLong(time));
            cacheConfig = cacheConfig.entryTtl(duration);
            //修改缓存key和value值的序列化方式
            cacheConfig = cacheConfig.computePrefixWith(DEFAULT_CACHE_KEY_PREFIX)
                    .serializeValuesWith(DEFAULT_PAIR);
            final String cacheName = StringUtils.substring(name, 0, lastIndexOf);
            return super.createRedisCache(cacheName, cacheConfig);
        }else{
            //修改缓存key和value值的序列化方式
            cacheConfig = cacheConfig.computePrefixWith(DEFAULT_CACHE_KEY_PREFIX)
                    .serializeValuesWith(DEFAULT_PAIR);
            return super.createRedisCache(name, cacheConfig);
        }
    }
}

使用方式

@Cacheable(cacheNames = "ssss#30" ,key = "#aaa+'_'+#beginTime+'_'+#endTime")

cacheNames/value ：用来指定缓存组件的名字

key ：缓存数据时使用的 key，可以用它来指定。默认是使用方法参数的值。（这个 key 你可以使用 spEL 表达式来编写）

keyGenerator ：key 的生成器。 key 和 keyGenerator 二选一使用

cacheManager ：可以用来指定缓存管理器。从哪个缓存管理器里面获取缓存。

condition ：可以用来指定符合条件的情况下才缓存

unless ：否定缓存。当 unless 指定的条件为 true ，方法的返回值就不会被缓存。当然你也可以获取到结果进行判断。（通过 #result 获取方法结果）

sync ：是否使用异步模式。

关于序列化的问题 返回值如果是个对象请添加 implements Serializable 否正会报错

不建议之间放到controller层，有时会序列化失败并且还没有走业务逻辑，建议放到查数据库的位置就可以只缓存查数据库的时间，业务逻辑不会忽略避免出现缺失业务逻辑出现的bug