Redis存储JSONObject报错：Java 8 LocalDateTime类型默认不支持

1. 确认依赖版本一致性 #

如果是Spring Boot项目，不要手动指定jackson-datatype-jsr310的版本，依赖Spring Boot父工程的版本管理即可，避免和核心jackson包版本冲突：

<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jsr310</artifactId>
</dependency>

2. 正确配置ObjectMapper #

注册JavaTimeModule的同时，显式配置LocalDateTime的序列化/反序列化格式，避免默认格式问题，并用@Primary确保该实例全局优先：

@Primary
@Bean
public ObjectMapper objectMapper() {
    ObjectMapper objectMapper = new ObjectMapper();
    JavaTimeModule timeModule = new JavaTimeModule();
    
    // 自定义LocalDateTime序列化格式
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    timeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(formatter));
    timeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(formatter));
    
    objectMapper.registerModule(timeModule);
    objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
    return objectMapper;
}

3. 让RedisTemplate使用自定义ObjectMapper #

Spring Boot默认的RedisTemplate不会自动复用你配置的ObjectMapper，需要手动指定序列化器：

@Bean
public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory, ObjectMapper objectMapper) {
    RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
    redisTemplate.setConnectionFactory(connectionFactory);
    
    Jackson2JsonRedisSerializer<Object> jsonSerializer = new Jackson2JsonRedisSerializer<>(Object.class);
    jsonSerializer.setObjectMapper(objectMapper);
    
    // 配置key和value的序列化方式
    redisTemplate.setKeySerializer(new StringRedisSerializer());
    redisTemplate.setValueSerializer(jsonSerializer);
    redisTemplate.setHashKeySerializer(new StringRedisSerializer());
    redisTemplate.setHashValueSerializer(jsonSerializer);
    
    redisTemplate.afterPropertiesSet();
    return redisTemplate;
}

4. 缓存注解场景的额外配置 #

如果使用@Cacheable等缓存注解，还需配置CacheManager适配自定义序列化：

@Bean
public CacheManager cacheManager(RedisConnectionFactory connectionFactory, ObjectMapper objectMapper) {
    Jackson2JsonRedisSerializer<Object> jsonSerializer = new Jackson2JsonRedisSerializer<>(Object.class);
    jsonSerializer.setObjectMapper(objectMapper);
    
    RedisCacheConfiguration cacheConfig = RedisCacheConfiguration.defaultCacheConfig()
            .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jsonSerializer));
    
    return RedisCacheManager.builder(connectionFactory)
            .cacheDefaults(cacheConfig)
            .build();
}

内容的提问来源于stack exchange，提问作者developer