How to Create Dialog Series Datepicker - Java

MyDialogFragment.java

public class MyDialogFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener {

    @NonNull
    @Override
    public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {

        // デフォルトの日付を用意
        final Calendar c = Calendar.getInstance();
        int year = c.get(Calendar.YEAR);
        int month = c.get(Calendar.MONTH);
        int day = c.get(Calendar.DAY_OF_MONTH);

        return new DatePickerDialog(requireContext(), this, year, month, day);
    }

    @Override
    public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
        String msg = year + "年" + (month+1) + "月" + dayOfMonth + "日";
        Toast.makeText(requireContext(), msg, Toast.LENGTH_SHORT).show();
    }
}