计算两个日期之间的天数后(取自edittext)如何将日期显示到新的edittext中

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class MainActivity extends AppCompatActivity {

    private EditText startDateEditText;
    private EditText endDateEditText;
    private EditText resultEditText;
    private Button calculateButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        startDateEditText = findViewById(R.id.start_date_edittext);
        endDateEditText = findViewById(R.id.end_date_edittext);
        resultEditText = findViewById(R.id.result_edittext);
        calculateButton = findViewById(R.id.calculate_button);

        calculateButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String startDateString = startDateEditText.getText().toString();
                String endDateString = endDateEditText.getText().toString();

                SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
                try {
                    Date startDate = dateFormat.parse(startDateString);
                    Date endDate = dateFormat.parse(endDateString);

                    Calendar startCalendar = Calendar.getInstance();
                    startCalendar.setTime(startDate);
                    Calendar endCalendar = Calendar.getInstance();
                    endCalendar.setTime(endDate);

                    long startMillis = startCalendar.getTimeInMillis();
                    long endMillis = endCalendar.getTimeInMillis();
                    long diffMillis = endMillis - startMillis;
                    long diffDays = diffMillis / (24 * 60 * 60 * 1000);

                    resultEditText.setText(String.valueOf(diffDays));
                } catch (ParseException e) {
                    e.printStackTrace();
                }
            }
        });
    }
}