springboot 2.x配置redisTemplate及cacheManager

@Configuration
@EnableCaching
public class RedisConfig {
    @Bean
    public ObjectMapper objectMapper() {
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);
        om.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        return om;
    }

    /**
     * Jackson2JsonRedisSerializer和GenericJackson2JsonRedisSerializer的区别
     * https://blog.csdn.net/bai_bug/article/details/81222519
     */
//    @Bean
//    public GenericJackson2JsonRedisSerializer jackson2JsonRedisSerializer(ObjectMapper om) {
//        GenericJackson2JsonRedisSerializer serializer = new GenericJackson2JsonRedisSerializer(om);
//        return serializer;
//    }
    @Bean
    public Jackson2JsonRedisSerializer jackson2JsonRedisSerializer(ObjectMapper om) {
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        return jackson2JsonRedisSerializer;
    }

    @Bean
    public RedisTemplate<String, String> redisTemplate(RedisConnectionFactory redisConnectionFactory,
                                                       RedisSerializer jackson2JsonRedisSerializer) {
        StringRedisTemplate redisTemplate = new StringRedisTemplate(redisConnectionFactory);
        RedisSerializer stringSerializer = new StringRedisSerializer();

        redisTemplate.setKeySerializer(stringSerializer);//key序列化
        redisTemplate.setValueSerializer(jackson2JsonRedisSerializer);//value序列化
        redisTemplate.setHashKeySerializer(stringSerializer);//Hash key序列化
        redisTemplate.setHashValueSerializer(jackson2JsonRedisSerializer);//Hash value序列化
        redisTemplate.afterPropertiesSet();

        return redisTemplate;
    }


    @Bean
    public KeyGenerator keyGenerator() {
        return (o, method, objects) -> {
            StringBuilder sb = new StringBuilder();
            sb.append(o.getClass().getName());
            sb.append("." + method.getName() + "(");
            for (Object obj : objects) {
                sb.append(obj.toString());
            }
            sb.append(")");
            return sb.toString();
        };
    }

    /**
     * springboot2.x中，RedisCacheManager已经没有了单参数的构造方法
     * 1.x中通过参数redisTemplate配置的方式不可行
     */
    @Bean
    public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory, RedisSerializer jackson2JsonRedisSerializer) {
        RedisCacheConfiguration cacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofHours(1))  // 设置缓存有效期一小时
                .disableCachingNullValues()
                .computePrefixWith(cacheName -> "yourAppName".concat(":").concat(cacheName).concat(":"))
                .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(new StringRedisSerializer()))
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer));

        return RedisCacheManager.builder(redisConnectionFactory)
                .cacheDefaults(cacheConfiguration)
                .build();
    }
}

缓存注解的使用
@Cacheable
Spring 在执行 @Cacheable 标注的方法前先查看缓存中是否有数据，如果有数据，则直接返回缓存数据；若没有数据，执行该方法并将方法返回值放进缓存。
参数： value缓存名、 key缓存键值、 condition满足缓存条件、unless否决缓存条件

@CachePut
和 @Cacheable 类似，但会把方法的返回值放入缓存中, 主要用于数据新增和修改方法

@CacheEvict
方法执行成功后会从缓存中移除相应数据。
参数： value缓存名、 key缓存键值、 condition满足缓存条件、 unless否决缓存条件、 allEntries是否移除所有数据（设置为true时会移除所有缓存）

cacheManager只针对注解缓存有效

只使用redisTemplate不需要配置