RXTX getPortIdentifiers() stuck

Question

I have problem to read lit of serial ports.when programe reach at CommPortIdentifier.getPortIdentifier() it stuck for almost 5 minnutes. as I observe delay could be due to scaning all ports iin system. So how to avoid this 5 minutes delay?

Answer 1

How do you scan for available ports?

For instance, the code below will return string list of available serial ports:

public List<String> getAvailablePorts() {

    List<String> list = new ArrayList<String>();

    Enumeration portList = CommPortIdentifier.getPortIdentifiers();

    while (portList.hasMoreElements()) {
        CommPortIdentifier portId = (CommPortIdentifier) portList.nextElement();
        if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
            list.add(portId.getName());
        }
    }

    return list;
}

Edit: since actual solution is digged in comments, I add it here:

It appears that commPortIdentifier.getPortIdentifier(portName) indeed does port rescan under certain circumstances; fast workaround is to set fixed port list manually via gnu.io.rxtx.SerialPorts system property.