retrofit (UPDATE запрос)

package com.example.testingintents;

import androidx.appcompat.app.AppCompatActivity;

import android.os.AsyncTask;

import android.os.Bundle;

import android.util.Log;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

import java.io.IOException;

import java.util.ArrayList;

import java.util.TreeMap;

import retrofit2.Retrofit;

import retrofit2.converter.gson.GsonConverterFactory;

import retrofit2.http.Body;

import retrofit2.http.Field;

import retrofit2.http.GET;

import retrofit2.http.POST;

import retrofit2.http.Query;

import retrofit2.*;

public class MainActivity extends AppCompatActivity {

   Button button;

   TextView textView;

   @Override

   protected void onCreate(Bundle savedInstanceState) {

       super.onCreate(savedInstanceState);

       setContentView(R.layout.activity_main);

       button = findViewById(R.id.btn);

       textView = findViewById(R.id.tv_text);

       button.setOnClickListener(new View.OnClickListener() {

           @Override

           public void onClick(View v) {

               SendData sendData = new SendData();

               sendData.execute("https://h152771.s22.test-hf.su/");

           }

       });

   }

   class Answer{

       public boolean status;

       public String sql;

   }

   class User{

       public String name, surname, fathersName;

       int groupNumber, id;

       User(String name, String surname, String fathersName, int groupNumber, int id){

           this.name = name;

           this.surname = surname;

           this.groupNumber = groupNumber;

           this.fathersName = fathersName;

           this.id = id;

       }

   }

   interface UserUpdate{

       @POST("temnov/mind_test.php") //Посылать будем методом POST

       Call<Answer> update(@Body User user); // @Body - так мы пошлем объект user в JSON-е

   }

   class SendData extends AsyncTask<String, Integer, Answer>{

       @Override

       protected Answer doInBackground(String... strings) {

           Answer answer = null;

           Retrofit retrofit = new Retrofit.Builder()

                   .baseUrl(strings[0])

                   .addConverterFactory(GsonConverterFactory.create())

                   .build();

           UserUpdate userUpdate = retrofit.create(UserUpdate.class);

           User user = new User("Василий", "Васильев", "Васильевич", 1, 1); // Взяли юзера, которого надо обновить

           Call<Answer> call = userUpdate.update(user); //Вот этот метод вызовется для обновления

           try {

               Response<Answer> response = call.execute(); // Обновили

               answer = response.body(); // Получили ответ от сервыера

           } catch (IOException e) {

               e.printStackTrace();

           }

           return answer;

       }

       @Override

       protected void onPostExecute(Answer answer) {

           super.onPostExecute(answer);

           textView.append(String.valueOf(answer.sql) + "\n");

       }

   }

}