Check the DocumentEvent in DocumentListener for JTextField in Java

import java.awt.FlowLayout;
/*from   w  ww  . j  a va2 s.co  m*/
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;

public class Main {
  public static void main(String[] args) {
    JFrame f = new JFrame("Text Field Elements");

    f.setLayout(new FlowLayout());


    JTextField textfield = new JTextField(10);
    textfield.getDocument().addDocumentListener(new MyDocListener());

    f.add(textfield);
    f.pack();
    f.setVisible(true);

  }


}

class MyDocListener implements DocumentListener {
  public void changedUpdate(DocumentEvent documentEvent) {
    printIt(documentEvent);
  }

  public void insertUpdate(DocumentEvent documentEvent) {
    printIt(documentEvent);
  }

  public void removeUpdate(DocumentEvent documentEvent) {
    printIt(documentEvent);
  }

  private void printIt(DocumentEvent documentEvent) {
    DocumentEvent.EventType type = documentEvent.getType();
    String typeString = null;
    if (type.equals(DocumentEvent.EventType.CHANGE)) {
      typeString = "Change";
    } else if (type.equals(DocumentEvent.EventType.INSERT)) {
      typeString = "Insert";
    } else if (type.equals(DocumentEvent.EventType.REMOVE)) {
      typeString = "Remove";
    }
    System.out.print("Type  :   " + typeString + " / ");
    Document source = documentEvent.getDocument();
    int length = source.getLength();
    try {
      System.out
          .println("Contents: " + source.getText(0, length));
    } catch (BadLocationException badLocationException) {
      System.out.println("Contents: Unknown");
    }
  }
};