//API Service

public interface ApiService {
 @POST("apiName.php")
 Call<ResponseBody> uploadImage(@Body RequestBody file,
                                      @Query("user_id") String user_id,
                                      @Query("number") String number);
 }
 
 
 //Base URL
 public class ApiUtilities {

    //Live
   // public static final String baseurl = "BASE URL";

    public static ApiService getApiservice() {
        return RetrofitClient.getClient(baseurl).create(ApiService.class);
    }
}


//Intercepter
public class RetrofitClient {

    public static Retrofit retrofit = null;

    public static Retrofit getClient(String baseurl) {
        if (retrofit == null) {
          
            retrofit = new Retrofit.Builder().baseUrl(baseurl)
                    .addConverterFactory(GsonConverterFactory.create())
                    .build();
        }
        return retrofit;
    }
}