package edu.probes.java;
 
import java.awt.BorderLayout;
 
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
 
public class MainFrame extends JFrame implements DocumentListener {
 
	private JTextField text = new JTextField(20);
	private String textInJTextField;
 
	public MainFrame() {
		text.getDocument().addDocumentListener(this);
 
		this.add(text, BorderLayout.NORTH);
                this.setSize(500, 100);
 
	}
 
	@Override
	public void insertUpdate(DocumentEvent e) {
		textInJTextField = text.getText();
		print(textInJTextField);
 
	}
 
	@Override
	public void removeUpdate(DocumentEvent e) {
		textInJTextField = text.getText();
		print(textInJTextField);
 
	}
 
	@Override
	public void changedUpdate(DocumentEvent e) {		
	}
 
	public void print(String s) {
		System.out.println(s);
	}
}

package edu.probes.java;
 
public class MainApp {
	public static void main(String args[]) {
		MainFrame fm = new MainFrame();
		fm.setVisible(true);
	}
 
}
 

public MainFrame ()