[SOLVED] SerialPort and Thread: can't read from the input stream.

[Francesco Fraccaroli]

Hi colleague developers, I've got a problem in communicating with serial port. In my applcation I have to receive some data from the serial port and to manage them for some operation. For now I'm just trying to write out the data received. I've create a test class with main() that manage the connection (open the port, set the parameters) and starts a thread. The thread is started in this manner:

    try {
        (new Thread(new Lettore(port), "Lettore")).start();
    } catch (Exception e) {
        System.err.println("Errore " + e);
    }

where the "port"parameter is the SerialPort object. The "Lettore" class contains the follow:

SerialPort port;

public Lettore(SerialPort port) throws IOException {
    this.port = port;
}

@Override
public void run() {
    byte\[\] buffer = new byte\[1024\];
    int len = -1;
        try {
        while (true) {
            //read, write on terminal, echo.
            len = port.getInputStream().read(buffer);
            System.out.print(new String(buffer, 0, len));
            if (len != 0) {
                port.getOutputStream().write(buffer, 0, len);
            }
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

}

In this case, the code in the thread seems to be never executed: no characters are show on the terminal and on the other station of the communication. On the other hand, if I write the same code of the run() function in the main, it works fine. Someone has ever got this problem? Can anyone help me?

[Lost User]

You need to make your thread runnable, as described in http://docs.oracle.com/javase/tutorial/essential/concurrency/runthread.html[^].

[Francesco Fraccaroli]

Dear Richard, thanks for the reply. I made the thread runnable by "implements Runnable" on the "Lettore" class definition, now it works. Thank you very much! The final code is this:

public class Lettore implements Runnable {

SerialPort port;

public Lettore(SerialPort port) throws IOException {
    this.port = port;
}

@Override
public void run() {
    byte\[\] buffer = new byte\[1024\];
    int len = -1;
        try {
        while (true) {
            //read, write on terminal, echo.
            len = port.getInputStream().read(buffer);
            System.out.print(new String(buffer, 0, len));
            if (len != 0) {
                port.getOutputStream().write(buffer, 0, len);
            }
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}

}