How to send request with query parameter using Retrofit 2?

URL: http://btownmedia.com/wp-json/wp/v2/categories/?parent=10

step 1:

public interface RetrofitArrayAPI {

@GET("wp/v2/categories/")
Call<List<ChildCategories>> getListCat(@Query("parent")int pid);

}


step 2:

out side the onCreate Method

private void getCategoriesList(int pid) {

   Retrofit retrofit = new Retrofit.Builder()
         .baseUrl(url)
         .addConverterFactory(GsonConverterFactory.create())
         .build();

   RetrofitArrayAPI service = retrofit.create(RetrofitArrayAPI.class);

   Call<List<ChildCategories>> call = service.getListCat(pid);

   call.enqueue(new Callback<List<ChildCategories>>() {
      @Override      public void onResponse(Response<List<ChildCategories>> response, Retrofit retrofit) {

         try {

            List<ChildCategories> CategoryData = response.body();

            for (int i = 0; i < CategoryData.size(); i++) {
               ChildCategories b = new ChildCategories();
               b.setId(CategoryData.get(i).getId());
               b.setName(CategoryData.get(i).getName());


            // Log.d("Category[" + i + "]", String.valueOf(CategoryData.get(i).getId()));            // Log.d("CategoryName", String.valueOf(CategoryData.get(i).getName()));
               //Log.d(TAG, String.valueOf(CategoryData.get(i).getName()));
               bsArry.add(b);
            }
            ChildCategories cc = new ChildCategories();
            for (int i = 0; i < bsArry.size(); i++) {
               cc = (ChildCategories) bsArry.get(i);

               Log.d("Business", cc.getName());

               bsinfi.add(cc.getName());

            }

         } catch (Exception e) {
            Log.d("onResponse", "There is an error");
            e.printStackTrace();
         }

      }

      @Override      public void onFailure(Throwable t) {
         Log.d("onFailure", t.toString());
      }
   });

}

Step 3:

call in onCreate() method {

getCategoriesList(7)

}