如何从只读基础 class 覆盖 JSON 字段并改用子字段？

Question

I have a base class (read-only) to fetch data from external API:

public class Manager {
 // so many fields
 public User user;
 // ...
}

Since field user is lost some fields, so I need to create new User class.

public class NewUser extends com.readonly.User {

    public String avatarUrl;
    public String fullname;
    public String address;
    // ....
}

Then I create NewManager and use it to fetch data from API.

public class NewManager extends com.readonly.Manager {
 // so many fields
 public NewUser user;
 // ...
}

But I got Error:

java.lang.IllegalArgumentException: class com.sovannarith.model.NewManager declares multiple JSON fields named user
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:172) ~[gson-2.8.6.jar:na]
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:102) ~[gson-2.8.6.jar:na]
    at com.google.gson.Gson.getAdapter(Gson.java:458) ~[gson-2.8.6.jar:na]
    at com.google.gson.Gson.fromJson(Gson.java:931) ~[gson-2.8.6.jar:na]

Note

• API have field named: user
• In both Manager.class and NewManager.class has field named user
• I want to use field name user of NewUser.class , not of User.class

Is it possible to do that?

Answer 1

If there is no stringent requirements to use GSON, then try to use Jackson(ObjectMapper), it can serialize objects with same field names. (Jackson pretty much better IMHO)