使用Java CommAPI读取不到数据【急】

我使用Java CommAPI读取rs232串口的数据，按照网上说的下载Java Comm API配置后，把sun自带的那个示例程序运行了一边，但是什么反映也没有，没有显示任何数据。另外我电脑的rs232串口接了一个IC卡读卡器，在上面刷卡也没反应，100分请哪位帮我解决！QQ，msn联系都行，QQ：78891611，msn：rohsuton@gmail.com。示例代码如下：
/*
* @(#)SimpleRead.java 1.12 98/06/25 SMI
*
* Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
*
* Sun grants you ("Licensee") a non-exclusive, royalty free, license
* to use, modify and redistribute this software in source and binary
* code form, provided that i) this copyright notice and license appear
* on all copies of the software; and ii) Licensee does not utilize the
* software in a manner which is disparaging to Sun.
*
* This software is provided "AS IS," without a warranty of any kind.
* ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
* INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND
* ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY
* LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THE
* SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS
* BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
* INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES,
* HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING
* OUT OF THE USE OF OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* This software is not designed or intended for use in on-line control
* of aircraft, air traffic, aircraft navigation or aircraft
* communications; or in the design, construction, operation or
* maintenance of any nuclear facility. Licensee represents and
* warrants that it will not use or redistribute the Software for such
* purposes.
*/

import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.TooManyListenersException;

import javax.comm.CommPortIdentifier;
import javax.comm.PortInUseException;
import javax.comm.SerialPort;
import javax.comm.SerialPortEvent;
import javax.comm.SerialPortEventListener;
import javax.comm.UnsupportedCommOperationException;

public class SimpleRead implements Runnable, SerialPortEventListener {
static CommPortIdentifier portId;

static Enumeration portList;

InputStream inputStream;

SerialPort serialPort;

Thread readThread;

public static void main(String[] args) {
portList = CommPortIdentifier.getPortIdentifiers();

while (portList.hasMoreElements()) {
portId = (CommPortIdentifier) portList.nextElement();
if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
if (portId.getName().equals("COM1")) {
//if (portId.getName().equals("/dev/term/a")) {
SimpleRead reader = new SimpleRead();
}
}
}
}

public SimpleRead() {
try {
serialPort = (SerialPort) portId.open("MainClassApp", 2000);
} catch (PortInUseException e) {
}
try {
inputStream = serialPort.getInputStream();
} catch (IOException e) {
}
try {
serialPort.addEventListener(this);
System.out.println("1");
} catch (TooManyListenersException e) {
}
serialPort.notifyOnDataAvailable(true);
try {
serialPort.setSerialPortParams(19200, SerialPort.DATABITS_8, SerialPort.STOPBITS_1,
SerialPort.PARITY_NONE);
} catch (UnsupportedCommOperationException e) {
}
readThread = new Thread(this);
readThread.start();
}

public void run() {
try {
Thread.sleep(2000);
System.out.println("2");
} catch (InterruptedException e) {
}
}

public void serialEvent(SerialPortEvent event) {
System.out.println("a");
switch (event.getEventType()) {
case SerialPortEvent.BI:
case SerialPortEvent.OE:
case SerialPortEvent.FE:
case SerialPortEvent.PE:
case SerialPortEvent.CD:
case SerialPortEvent.CTS:
case SerialPortEvent.DSR:
case SerialPortEvent.RI:
case SerialPortEvent.OUTPUT_BUFFER_EMPTY:
break;
case SerialPortEvent.DATA_AVAILABLE:
byte[] readBuffer = new byte[20];

try {
while (inputStream.available() > 0) {
int numBytes = inputStream.read(readBuffer);
}
System.out.print(new String(readBuffer));
} catch (IOException e) {
}
break;
}
}
}