Erreur java

package client;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.net.InetAddress;
	import java.net.InetSocketAddress;
	import java.net.Socket;
	import java.util.Enumeration;
import javax.comm.*;
public class Test 
{
		/**
		 * @param args
		 * @throws NoSuchPortException 
		 * @throws PortInUseException 
		 * @throws IOException 
		 * @throws UnsupportedCommOperationException 
		 * @throws InterruptedException 
		 */
		public static void main(String[] args) throws NoSuchPortException, PortInUseException, IOException, UnsupportedCommOperationException, InterruptedException {	
			Enumeration<CommPortIdentifier> enumP = CommPortIdentifier.getPortIdentifiers();
			Socket client = null;
			
			while(enumP.hasMoreElements()) {
				try
				{
				CommPortIdentifier tmp = enumP.nextElement();
				System.out.println(tmp.getName());
				SerialPort serial = (SerialPort) tmp.open("eee", 2000 );
				serial.setSerialPortParams(19200, SerialPort.DATABITS_8,SerialPort.STOPBITS_1,  SerialPort.PARITY_NONE);
				serial.notifyOnDataAvailable(true);
				serial.notifyOnOutputEmpty(true);
				serial.getOutputStream().write("AT+CIMI".getBytes());
				InputStream is = serial.getInputStream();
				byte[] b = new byte[512];
				is.read(b);
				String s=b.toString().trim();
				System.out.println("Le message réçu est :\n" +s);
				System.out.println("Finished");
				serial.close();
				}catch(Exception e)
				{
					e.getStackTrace();
				}
			}
		}
	}