ChangeListener, KeyListener, ActionListener

SliderFrame (JSlider, JLabel, JTextfield, JButton)

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JTextField;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

// SliderFrame shows ChangeListener, KeyListener, ActionListener
public class SliderFrame extends JFrame implements ChangeListener, KeyListener, ActionListener {

    JPanel panel = new JPanel(new BorderLayout());
    JPanel panel1 = new JPanel(new FlowLayout());
    JSlider slider = new JSlider(JSlider.HORIZONTAL, 0, 100, 20);
    JLabel label = new JLabel("Value : ", JLabel.CENTER);
    JTextField textfield = new JTextField(10);
    JButton button = new JButton("Close");

    public SliderFrame(String name) {
        super(name);

        this.add(panel);
        this.panel1.add(label);
        this.panel1.add(textfield);
        this.panel.add(slider, BorderLayout.CENTER);
        this.panel.add(panel1, BorderLayout.NORTH);
        this.panel.add(button, BorderLayout.SOUTH);

        this.slider.addChangeListener(this); // ChangeListener stateChanged
        this.textfield.addKeyListener(this); // KeyListener keyTyped, keyPressed, keyReleased
        this.button.addActionListener(this); // ActionListener actionPerformed

        this.setSize(250, 150);
        this.setVisible(true);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    public static void main(String[] args) {
        new SliderFrame("SliderFrame");
    }

    @Override
    public void stateChanged(ChangeEvent e) {
        JSlider s = (JSlider)e.getSource();
        textfield.setText("" + s.getValue()); 
    }

    @Override
    public void keyTyped(KeyEvent e) { 
    }

    @Override
    public void keyPressed(KeyEvent e) {
    }

    @Override
    public void keyReleased(KeyEvent e) {
        int key = e.getKeyCode();
        if (key == KeyEvent.VK_ENTER) {
            Toolkit.getDefaultToolkit().beep(); 
            System.out.println("ENTER pressed");
            JTextField t = (JTextField) e.getSource();
            int value = Integer.parseUnsignedInt(t.getText());
            slider.setValue(value);
        }
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        JButton b = (JButton)e.getSource();
        if (b == button) {
            this.setVisible(false);
            this.dispose();
        }
    }
}