Redis获取缓存异常：java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to XXX。java
出现这种异常，我须要自定义ObjectMapper，设置一些参数，而不是直接使用Jackson2JsonRedisSerializer类中黙认的ObjectMapper，看源代码能够知道，Jackson2JsonRedisSerializer中的ObjectMapper是直接使用new ObjectMapper()建立的，这样ObjectMapper会将Redis中的字符串反序列化为java.util.LinkedHashMap类型，致使后续Spring对其进行转换成报错。其实咱们只要它返回Object类型就能够了。redis
使用如下方法，构建一个Jackson2JsonRedisSerializer对象，将其注入RedisCacheConfiguration便可。缓存
private Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer() { Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer<>(Object.class); ObjectMapper objectMapper = new ObjectMapper(); objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); objectMapper.configure(MapperFeature.USE_ANNOTATIONS, false); objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false); objectMapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false); // 此项必须配置，不然会报java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to XXX objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY); objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL); jackson2JsonRedisSerializer.setObjectMapper(objectMapper); return jackson2JsonRedisSerializer; } @Bean public RedisCacheManager redisCacheManager(RedisConnectionFactory connectionFactory){ //初始化一个RedisCacheWriter输出流 RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(connectionFactory); //采用Jackson2JsonRedisSerializer序列化机制 // Jackson2JsonRedisSerializer<Object> serializer = new Jackson2JsonRedisSerializer<Object>(Object.class); //建立一个RedisSerializationContext.SerializationPair给定的适配器pair RedisSerializationContext.SerializationPair<Object> pair = RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer()); //建立CacheConfig RedisCacheConfiguration defaultCacheConfig = RedisCacheConfiguration.defaultCacheConfig().serializeValuesWith(pair); return new RedisCacheManager(redisCacheWriter, defaultCacheConfig); }