import javax.swing.*;
import java.awt.Font;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.util.*;
import java.text.DateFormat;

// Adaptación de la clase de repaso de Java, 2d, p. 333

public class SimpleClock
    extends javax.swing.JPanel
    implements Runnable
{
    private Font clockFont = new Font( "SansSerif", Font.BOLD, 24 );
    private Thread clockThread = null;
    private int xPos = 40;
    private int yPos = 50;
    private DateFormat df;
    
    public SimpleClock()
    {
        df = DateFormat.getTimeInstance();
        setBorder( BorderFactory.createLineBorder( Color.black, 2 ) );
        setFont( clockFont );
        setForeground( Color.red );
        setPreferredSize( new Dimension( 200, 100 ));
        clockThread = new Thread( this, "Clock" );
        clockThread.start();
    }
    
    public void paintComponent( Graphics g )
    {
        super.paintComponent( g );
        Date date = Calendar.getInstance().getTime();
        String time = df.format( date );
        g.drawString( time, xPos, yPos );
    }
    
    public void run()
    {
        while ( true )
        {
            repaint();
            try
            {
                Thread.sleep( 1000 );
            }
            catch (InterruptedException e )
            {}
        }
    }
    
    public static void main( String [] args )
    {
        JFrame frame = new JFrame( "SimpleClock" );
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        SimpleClock theClock = new SimpleClock();
        frame.getContentPane().add( theClock, BorderLayout.CENTER );
        frame.pack();
        frame.setVisible( true );
    }
}