import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.Document;
class MyDocumentListener implements DocumentListener {
final String newline = "\n";
public void insertUpdate(DocumentEvent e) {
updateLog(e, "inserted into");
}
public void removeUpdate(DocumentEvent e) {
updateLog(e, "removed from");
}
public void changedUpdate(DocumentEvent e) {
//Plain text components don't fire these events.
}
public void updateLog(DocumentEvent e, String action) {
Document doc = (Document)e.getDocument();
int changeLength = e.getLength();
System.out.println(
changeLength + " character"
+ ((changeLength == 1) ? " " : "s ")
+ action + " " + doc.getProperty("name") + "."
+ newline
+ " Text length = " + doc.getLength() + newline);
}
}
public class UsingDocumentListener {
public static void main(String[] a){
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTextField textField = new JTextField();
textField.getDocument().addDocumentListener(new MyDocumentListener());
textField.getDocument().putProperty("name", "Text Field");
frame.add(textField);
frame.setSize(300, 200);
frame.setVisible(true);
}
}