the sample code to use JsonDeserializer to handle the nest/complicate JSON format

sample_gson_deserializer

/**
* Example : 
*    input : {server: { result : { data: { a:1, b:2 }} }} 
**/

public class MyDeserializer implements JsonDeserializer<MyClass> {
  public MyClass deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
      throws JsonParseException {        
      JsonElement j = json.getAsJsonObject().get("server").getAsJsonObject().get("result").getAsJsonObject().get("data");
      MyClass clz = new MyClass();
      clz.data = context.deserialize(j, MyData.class);
      return clz;
  }
}

public class MyClass {
  public MyData data;
}

public class MyData {
   @Serialize("a")
   public int a;
   @Serialize("b")
   public int b;
}