import java.awt.Component;
import java.awt.Container;
import java.io.File;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class Main {
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JButton button = new JButton("Click me");
button.addActionListener(e -> {
JFileChooser chooser = new JFileChooser();
chooser.setSelectedFile(new File(chooser.getCurrentDirectory(),
"save.dat"));
final JTextField textField = getTexField(chooser);
if (textField == null) {
return;
}
String text = textField.getText();
if (text == null) {
return;
}
int index = text.lastIndexOf('.');
if (index == -1) {
return;
}
textField.setSelectionStart(0);
textField.setSelectionEnd(index);