If the properties of the model are private, Android cannot convert the JSON response to the model

I tried to use retrofit on Android, but I encountered this problem. I want to get data from the API in JSON format and convert it into a model in my application

This is my model

public class A {
   private String property1;
   private int property2;

   //default constructor, getter and setter below
}

This is my service

public interface TestService {
   @GET("/a")
   void getA(Callback<A> callback);
}

When I use testservice to retrieve data, it will not return an error, but will return the empty class of A. if I change the property of class A to public, it will be converted to the correct object a

Editing questions

This is the JSON example I want to convert to model a

{
   "property1" : "content",
   "property2" : 1
}

resolvent:

If you are using gson, use the expose annotation on the private field

Like:

@Expose
private String property1;

@Expose
private int property2;

If you want to use a different name for a variable, you can try using the serializedname annotation, for example:

@Expose
@SerializedName("property1")
private String p1;

@Expose
@SerializedName("property2")
private int p2;

I think if we don't publish the complete "a" course, it should be OK