jar file not reading input from serial port

i used a coding for getting data from serial port. JOptionbox with "port not found" message is shown when i execute thru jar file. but when i execute thru netbeans, data is received from comm port. why it is happening? i attached the coding i used.

public class SimpleRead implements Runnable, SerialPortEventListener { static CommPortIdentifier portId; static Enumeration portList; InputStream inputStream; SerialPort serialPort; Thread readThread;

public static void main(String[] args) { boolean portFound = false; String defaultPort = "COM2";

portList = CommPortIdentifier.getPortIdentifiers();

while (portList.hasMoreElements()) { portId = (CommPortIdentifier) portList.nextElement(); if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) { if (portId.getName().equals(defaultPort)) { JOptionPane.showMessageDialog("Found port: "+defaultPort);
portFound = true; SimpleRead reader = new SimpleRead(); } } } if (!portFound) { JOptionPane.showMessageDialog("port " + defaultPort + " not found."); } }

private int numBytes; private String s;

public SimpleRead() { try { serialPort = (SerialPort) portId.open("SimpleReadApp", 2000); } catch (PortInUseException e) { System.out.println("port in use"); }

try { System.out.println("Getting input Stream"); inputStream = serialPort.getInputStream(); } catch (IOException e) { System.out.println(e); }

try { serialPort.addEventListener(this); } catch (TooManyListenersException e) { System.out.println(e); } serialPort.notifyOnDataAvailable(true); try { serialPort.setSerialPortParams(9600, 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); } catch (InterruptedException e) {} }

public void serialEvent(SerialPortEvent event) { 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.OUTPUTBUFFEREMPTY: break;

case SerialPortEvent.DATA_AVAILABLE: byte[] readBuffer = new byte[8]; byte[] readBuffer2=null; try { while (inputStream.available() > 0) { numBytes = inputStream.read(readBuffer); readBuffer2= new byte[numBytes]; for(int i=0;i

}
s = new String(readBuffer2);
System.out.println("readbuffer......"+ s);

} catch (IOException e) {}
break;

} } }