jcakson3构建ObjectMapper开源

开源地址

https://github.com/NekoNekoCloud/article-like-vote

自springboot4.0开始，Jackson2JsonRedisSerializer就被移除，支持JacksonJsonRedisSerializer

JacksonJsonRedisSerializer是一个可以使用 Jackson 3 和 Jackson 3 Databind 的 ObjectMapper 读写 JSON 的 Redis 序列化器。

该序列化器可用于绑定到类型化的 Bean，或非类型化的 HashMap 实例。注意：空对象会被序列化为空数组，反之亦然（即空数组也会被反序列化为空对象）。

可以通过配置 JacksonObjectReader 和 JacksonObjectWriter 来分别定制 JSON 的读取和写入行为。”

RedisSerializer that can read and write JSON using Jackson 3 and Jackson 3 Databind . ObjectMapper

This serializer can be used to bind to typed beans, or untyped HashMap instances. Note:Null objects are serialized as empty arrays and vice versa.

JSON reading and writing can be customized by configuring JacksonObjectReader respective JacksonObjectWriter.

在 Spring 博客的《Introducing Jackson 3 support in Spring》中明确写道：

Jackson 3 introduces a lot of changes and enhancements, but from a Spring perspective one of the most important ones to understand and embrace is the switch from a mutable ObjectMapper in Jackson 2 to an immutable JsonMapper in Jackson 3.

JsonMapper, which extends ObjectMapper, is specific to the JSON format, following a similar pattern than other formats (XmlMapper, YAMLMapper, SmileMapper, etc.) and Spring support has been updated to use this format specific variant, following Jackson 3 best practices.

Also with Jackson and Spring defaults mostly aligned, and the introduction of a first class JsonMapper.Builder, Spring Framework does not provide an equivalent for Jackson2ObjectMapperBuilder, you should just use the Jackson builder.

这段话直接点明了：Jackson 2 的 ObjectMapper 是可变的，而 Jackson 3 的 JsonMapper 是不可变的，必须使用 Builder 构建。

Jackson2JsonRedisSerializer （Spring Data Redis 4.0.3 API）

Introducing Jackson 3 support in Spring