• SpringBoot 配置 Redis 多缓存名(不同缓存名缓存失效时间不同)


    import com.google.common.collect.ImmutableMap;
    import org.springframework.cache.CacheManager;
    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.lettuce.LettuceConnectionFactory;
    import org.springframework.data.redis.core.RedisTemplate;
    import org.springframework.data.redis.serializer.RedisSerializationContext;
    import org.springframework.data.redis.serializer.StringRedisSerializer;
    
    import java.time.Duration;
    import java.util.Map;
    
    @Configuration
    public class RedisConfig {
        @Bean
        public RedisTemplate<String, Object> redisTemplate(LettuceConnectionFactory factory) {
            RedisTemplate<String, Object> template = new RedisTemplate();
            template.setConnectionFactory(factory);
            StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
            //配置使用FastJson进行序列化和反序列化操作
            FastJsonRedisSerializer<Object> fastJsonRedisSerializer = new FastJsonRedisSerializer<>(Object.class);
            template.setKeySerializer(stringRedisSerializer);
            template.setHashKeySerializer(stringRedisSerializer);
            template.setValueSerializer(fastJsonRedisSerializer);
            template.setHashValueSerializer(fastJsonRedisSerializer);
            template.afterPropertiesSet();
            //开启Redis事务
            /**
            * 为何要开启事务呢?redis本身是单线程执行的one by one 
            * 虽然都是原子性操作,那需要多个原子性的操作才算一个完整的事件呢
            * 譬如 redis get set可能就是一对操作才能保证操作的完整性
            * 譬如记录访问数 value 从0开始,在并发情况下多线程会同时查询到 value 为0 的情况,
            * 此时两线程都得到value 0 为此都 +1操作 执行结果 value=1,而我们期望的结果至少是2才对
            * 所以需要用事务来解决这一堆操作(get set)
            */
            template.setEnableTransactionSupport(true);
            return template;
        }
    
        @Bean
        public CacheManager cacheManager(RedisTemplate<String, Object> template) {
            
            //配置多个缓存名称 这里我们用个能用的模板  这里有坑点往下看
            RedisCacheConfiguration templateRedisCacheCfg = RedisCacheConfiguration
                    .defaultCacheConfig()
                    // 设置key为String
                    .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(template.getStringSerializer()))
                    // 设置value 为自动转Json的Object
                    .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(template.getValueSerializer()))
                    // 不缓存null
                    .disableCachingNullValues();
            //这里对RedisCacheConfiguration不熟悉的可能会有疑问,我们这样批量templateRedisCacheCfg.entryTtl(Duration.ofMinutes(15))最后不都是同一个引用吗,过期时间会生效吗?
            Map<String, RedisCacheConfiguration> expires = ImmutableMap.<String, RedisCacheConfiguration>builder()
                    .put("15m", templateRedisCacheCfg.entryTtl(Duration.ofMinutes(15)))
                    .put("30m", templateRedisCacheCfg.entryTtl(Duration.ofMinutes(30)))
                    .put("60m", templateRedisCacheCfg.entryTtl(Duration.ofMinutes(60)))
                    .put("1d", templateRedisCacheCfg.entryTtl(Duration.ofDays(1)))
                    .put("30d", templateRedisCacheCfg.entryTtl(Duration.ofDays(30)))
                    .put("common-30d", templateRedisCacheCfg.entryTtl(Duration.ofDays(30)))
                    .build();
    
            RedisCacheManager redisCacheManager =
                    RedisCacheManager.RedisCacheManagerBuilder
                            // Redis 连接工厂
                            .fromConnectionFactory(template.getConnectionFactory())
                            // 默认缓存配置
                            .cacheDefaults(templateRedisCacheCfg.entryTtl(Duration.ofHours(1)))
                            // 配置同步修改或删除 put/evict
                            .transactionAware()
                            .initialCacheNames(expires.keySet())
                            .withInitialCacheConfigurations(expires)
                            .build();
            return redisCacheManager;
        }
    }
    
    

    序列化类

    
    import com.alibaba.fastjson.JSON;
    import com.alibaba.fastjson.serializer.SerializerFeature;
    import org.springframework.data.redis.serializer.RedisSerializer;
    import org.springframework.data.redis.serializer.SerializationException;
    
    import java.nio.charset.Charset;
    
    
    public class FastJsonRedisSerializer<T> implements RedisSerializer<T> {
    
        public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
    
        private Class<T> clazz;
    
        public FastJsonRedisSerializer(Class<T> clazz) {
            super();
            this.clazz = clazz;
        }
    
        @Override
        public byte[] serialize(T t) throws SerializationException {
            if (t == null) {
                return new byte[0];
            }
            return JSON.toJSONString(t, SerializerFeature.WriteClassName,SerializerFeature.WriteNullStringAsEmpty,SerializerFeature.WriteMapNullValue,SerializerFeature.WriteNullListAsEmpty).getBytes(DEFAULT_CHARSET);
        }
    
        @Override
        public T deserialize(byte[] bytes) throws SerializationException {
            if (bytes == null || bytes.length <= 0) {
                return null;
            }
            String str = new String(bytes, DEFAULT_CHARSET);
            return JSON.parseObject(str, clazz);
        }
    }
    
    
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  • 原文地址:https://www.cnblogs.com/dadiwm321/p/springboot_redis.html
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