Redistemplate handles hash integer type problem resolution

1、 problem

RedisTemplate When in the configuration , Set up hash The value of is serialized as GenericJackson2JsonRedisSerializer, When writing data, the data type is Long, But the value is small . When reading , Assign a value to Long type , Will prompt java.lang.Integer To java.lang.Long Type of mistake .

2、 Cause analysis

OjbectMapper#readValue(byte[] src, Class<T> valueType) For reading hash Of value value , It will call _findRootDeserializer To find the serializer , The call findRootValueDeserializer To find serialization . 

findRootValueDeserializer Would call DeserializerCache#findValueDeserializer To determine which Deserializer, The final call is DeserializerCache#_createDeserializer2, call DeserializerFactory#createBeanDeserializer, As a matter of fact, BeanDeserializerFactory#createBeanDeserializer

about Class The type is Object Type of , Use UntypedObjectDeserializer.

During deserialization , The handling of numeric types is

  If there are shaping related parameters in the context

• DeserializationFeature.USE_LONG_FOR_INTS when , use Long To represent integer data
• DeserializationFeature.USE_BIG_INTEGER_FOR_INTS, Use large integers to represent integer data
• In other cases , Use JsonParser#getNumberValue To handle integers ,ParserBase#getNumberValue It will be determined according to the length of the current integer Integer still Long