将JSON反序列化为现有对象（Java）
问题描述：
我想知道如何让Jackson JSON库将JSON反序列化为现有对象？我试图找到如何做到这一点;但它似乎只能采取一个类并自己实例化它。
I'd like to know how one might get the Jackson JSON library to deserialize JSON into an existing object? I've tried to find how to to this; but it seems to only be able to take a Class and instantiate it itself.
如果不可能，我想知道是否有任何Java JSON反序列化库可以做到这一点。
Or if not possible, I'd like to know if any Java JSON deserialization libraries can do it.
这似乎是C＃的一个相应问题：将数据从JSON字符串覆盖到现有对象实例。看来JSON.NET有一个PopulateObject（字符串，对象）。
This seems to be a corresponding question for C#: Overlay data from JSON string to existing object instance. It seems JSON.NET has a PopulateObject(string,object).
答
你可以用Jackson做到这一点：
You can do this using Jackson:
mapper.readerForUpdating(object).readValue(json);