Java Programming

At first I tried to download from the java comm.api from sun website,, but it came out with several errors I don't know why.

but javacomm20-win32.zip did the job.
I downloaded it from the [this site|http://www.filewatcher.com/m/javacomm20-win32.zip.272690.0.0.html]

Now, the problem is when this code runs it shows NO serial, parallel or unknown ports just blank.. when exits shows 'You chose null (known by null).'
but i checked device manger where I have printer port(LPT1) and Communications port (COM1) and several other ports.

Any idea why this is showing so? I am using windows XP.

import java.io.*;
import javax.comm.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
/**
 * Choose a port, any port!
 *
 * Java Communications is a "standard extension" and must be downloaded
 * and installed separately from the JDK before you can even compile this
 * program.
 *
 */
public class PortChooser extends JDialog implements ItemListener {

    /** A mapping from names to CommPortIdentifiers. */
    protected HashMap map = new HashMap();
    /** The name of the choice the user made. */
    protected String selectedPortName;
    /** The CommPortIdentifier the user chose. */
    protected CommPortIdentifier selectedPortIdentifier;
    /** The JComboBox for serial ports */
    protected JComboBox serialPortsChoice;
    /** The JComboBox for parallel ports */
    protected JComboBox parallelPortsChoice;
    /** The JComboBox for anything else */
    protected JComboBox other;
    /** The SerialPort object */
    protected SerialPort ttya;
    /** To display the chosen */
    protected JLabel choice;
    /** Padding in the GUI */
    protected final int PAD = 5;

    /** This will be called from either of the JComboBoxes when the
     * user selects any given item.
     */
    public void itemStateChanged(ItemEvent e) {
// Get the name
        selectedPortName = (String) ((JComboBox) e.getSource()).getSelectedItem();
// Get the given CommPortIdentifier
        selectedPortIdentifier = (CommPortIdentifier) map.get(selectedPortName);
// Display the name.
        choice.setText(selectedPortName);
    }
    /* The public "getter" to retrieve the chosen port by name. */

    public String getSelectedName() {
        return selectedPortName;
    }
    /* The public "getter" to retrieve the selection by CommPortIdentifier. */

    public CommPortIdentifier getSelectedIdentifier() {
        return selectedPortIdentifier;
    }

    /** A test program to show up this chooser. */
    public static void main(String[] ap) {
        PortChooser c = new PortChooser(null);
        c.setVisible(true);// blocking wait
        System.out.println("You chose " + c.getSelectedName()
                + " (known by " + c.getSelectedIdentifier() + ").");
        System.exit(0);
    }

    /** Construct a PortChooser --make the GUI and populate the ComboBoxes.
     */
    public PortChooser(JFrame parent) {
        super(parent, "Port Chooser", true);
        makeGUI();
        populate();
        finishGUI();
    }

    /** Build the GUI. You can ignore this for now if you have not
     * yet worked through the GUI chapter. Your mileage may vary.
     */
    protected void makeGUI() {
        Container cp = getContentPane();
        JPanel centerPanel = new JPanel();
        cp.add(BorderLayout.CENTER, centerPanel);
        centerPanel.setLayout(new GridLayout(0, 2, PAD, PAD));
        centerPanel.add(new JLabel("Serial Ports", JLabel.RIGHT));
        serialPortsChoice = new JComboBox();
        centerPanel.add(serialPortsChoice);
        serialPortsChoice.setEnabled(false);
        centerPanel.add(new JLabel("Parallel Ports", JLabel.RIGHT));
        parallelPortsChoice = new JComboBox();
        centerPanel.add(parallelPortsChoice);
        parallelPortsChoice.setEnabled(false);
        centerPanel.add(new JLabel("Unknown Ports", JLabel.RIGHT));
        other = new JComboBox();
        centerPanel.add(other);
        other.setEnabled(false);
        centerPanel.add(new JLabel("Your choice:", JLabel.RIGHT));
        centerPanel.add(choice = new JLabel());
        JButton okButton;
        cp.add(BorderLayout.SOUTH, okButton = new JButton("OK"));
        okButton.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {
                PortChooser.this.dispose();
            }
        });
    }

    /** Populate the ComboBoxes by asking the Java Communications API
     * what ports it has. Since the initial information comes from
     * a Properties file, it may not exactly reflect your hardware.
     */
    protected void populate() {
// get list of ports available on this particular computer,
// by calling static method in CommPortIdentifier.
        Enumeration pList = CommPortIdentifier.getPortIdentifiers();

// Process the list, putting serial and parallel into ComboBoxes
        while (pList.hasMoreElements()) {
            CommPortIdentifier cpi = (CommPortIdentifier) pList.nextElement();
// System.out.println("Port " + cpi.getName());
            map.put(cpi.getName(), cpi);
            if (cpi.getPortType() == CommPortIdentifier.PORT_SERIAL) {
                serialPortsChoice.setEnabled(true);
                serialPortsChoice.addItem(cpi.getName());
            } else if (cpi.getPortType() == CommPortIdentifier.PORT_PARALLEL) {
                parallelPortsChoice.setEnabled(true);
                parallelPortsChoice.addItem(cpi.getName());
            } else {
                other.setEnabled(true);
                other.addItem(cpi.getName());
            }
        }
        serialPortsChoice.setSelectedIndex(-1);
        parallelPortsChoice.setSelectedIndex(-1);
    }

    protected void finishGUI() {
        serialPortsChoice.addItemListener(this);
        parallelPortsChoice.addItemListener(this);
        other.addItemListener(this);
        pack();
        //addWindowListener(new WindowCloser(this, true));
    }
}