com.fasterxml.jackson.databind.exc.InvalidDefinitionException:
Cannot construct instance of `com.manlu.xxx.xxx` (no Creators, like default construct, exist):
cannot deserialize from Object value (no delegate- or property-based Creator)
com.fasterxml.jackson.databind.exc.InvalidDefinitionException:
无法构造“com.manlu.xxx.xxx”的实例（不存在与默认构造类似的创建者）：
无法从对象值反序列化（不存在基于委托或属性的创建者）
忘写无参构造了吧???