Hy ,

I have a example tooken from the internet , and compiler gives me this error :

The type CommPortIdentifier is not accessible due to restriction on required library C:\Program Files\Java\jre6\lib\ext\comm.jar

The code is:

import java.awt.*;
import java.io.*;
import javax.comm.*;
import java.util.*;
 * Open a serial port using Java Communications.
class CommPortOpen {
/** How long to wait for the open to finish up. */
public static final int TIMEOUTSECONDS = 30;
/** The baud rate to use. */
public static final int BAUD = 9600;
/** The parent Frame, for the chooser. */
protected Frame parent;
/** The input stream */
protected DataInputStream is;
/** The output stream */
protected PrintStream os;
/** The last line read from the serial port. */
protected String response;
/** A flag to control debugging output. */
protected boolean debug = true;
/** The chosen Port Identifier */
CommPortIdentifier thePortID;
/** The chosen Port itself */
CommPort thePort;
public static void main(String[] argv)
throws IOException, NoSuchPortException, PortInUseException,
UnsupportedCommOperationException {
new CommPortOpen(null).converse();
/* Constructor */
public CommPortOpen(Frame f) throws IOException, NoSuchPortException, PortInUseException,UnsupportedCommOperationException {
// Use the PortChooser from before. Pop up the JDialog.
PortChooser chooser = new PortChooser(null);
String portName = null;
do {
// Dialog done. Get the port name.
portName = chooser.getSelectedName();
if (portName == null)
System.out.println("No port selected. Try again.\n");
} while (portName == null);
// Get the CommPortIdentifier.
thePortID = chooser.getSelectedIdentifier();
// Now actually open the port.
// This form of openPort takes an Application Name and a timeout.
System.out.println("Trying to open " + thePortID.getName() + "...");
switch (thePortID.getPortType()) {
case CommPortIdentifier.PORT_SERIAL:
thePort = thePortID.open("DarwinSys DataComm",
SerialPort myPort = (SerialPort) thePort;
//set up the serial port
myPort.setSerialPortParams(BAUD, SerialPort.DATABITS_8,
SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);
case CommPortIdentifier.PORT_PARALLEL:
thePort = thePortID.open("DarwinSys Printing",
ParallelPort pPort = (ParallelPort)thePort;
// Tell API to pick "best available mode" - can fail!
// myPort.setMode(ParallelPort.LPT_MODE_ANY);
// Print what the mode is
int mode = pPort.getMode();
switch (mode) {
	case ParallelPort.LPT_MODE_ECP:
	System.out.println("Mode is: ECP");
	case ParallelPort.LPT_MODE_EPP:
	System.out.println("Mode is: EPP");
	case ParallelPort.LPT_MODE_NIBBLE:
	System.out.println("Mode is: Nibble Mode.");
	case ParallelPort.LPT_MODE_PS2:
	System.out.println("Mode is: Byte mode.");
	case ParallelPort.LPT_MODE_SPP:
	System.out.println("Mode is: Compatibility mode.");
// ParallelPort.LPT_MODE_ANY is a "set only" mode;
// tells the API to pick "best mode"; will report the
// actual mode it selected.
	throw new IllegalStateException
	("Parallel mode " + mode + " invalid.");
	default:// Neither parallel nor serial??
	throw new IllegalStateException("Unknown port type " + thePortID);
//Get the input and output streams
//Printers can be write-only
try {
	is = new DataInputStream(thePort.getInputStream());
	catch (IOException e) {
			System.err.println("Can't open input stream: write-only");
			is = null;
		os = new PrintStream(thePort.getOutputStream(), true);
	/** This method will be overridden by non-trivial subclasses
	 * to hold a conversation.
	protected void converse() throws IOException {
		System.out.println("Ready to read and write port.");
		// Input/Output code not written -- must subclass.
		// Finally, clean up.
		if (is != null)

I googled it , found some solutions but didn`t find the ways to deal with it

Are you sure you put the comm.jar file in the correct spot.

Are you sure you're the corrrect version (32 bit vs. 64 bit). You may think this is not going to help, but I once had a problem where I had both the 64 bit and 32 bit version installed and Java wasn't using one.

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