Java DocumentListener implement

import java.awt.FlowLayout;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;

public class Main extends JFrame {
  public Main() {
    super("JButton");

    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setLayout(new FlowLayout());
    JLabel nameLabel = new JLabel("Name:");
    JTextField name = new JTextField(20);

    name.getDocument().addDocumentListener(new DocumentListener() {

      @Override//w w w.j a v a 2  s  .c om
      public void insertUpdate(DocumentEvent e) {
        System.out.println(e);
      }

      @Override
      public void removeUpdate(DocumentEvent e) {
        System.out.println(e);
      }

      @Override
      public void changedUpdate(DocumentEvent e) {
        System.out.println(e);
      }
    });

    getContentPane().add(nameLabel);
    getContentPane().add(name);

  }

  public static void main(String[] args) {
    Main frame = new Main();
    frame.pack();
    frame.setVisible(true);
  }
}