ObjectMapper 是由Jackson library 所提供的一個功能，所以只要在maven 中加入 spring-boot-starter-web 的dependency 就可以了. ... <看更多>

Jackson has been known as "the Java JSON library" or "the best JSON parser for Java". Or simply as "JSON for Java". ... A good companion to this README is the ... ... <看更多>

OK finally I figured it out. The problem is, there is no type metadata for the root object. To fix this, I need to change the code: ... <看更多>