What does this exception message mean?

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The computer's system is Windows XP and the phone mobile is Alcatel OT-806D. They are connected through the mobile's USB cable. I launched a command line java J2SE program ( c:\>path_to_the_src\java net.Example ) :

package net;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Vector;

public class Example implements net.Network_iface {

    // set the speed of the serial port
    public static int speed = 115200;
    private static net.Network network;

    private static boolean resend_active = false;

    public static void main(String[] args) {
        network = new net.Network(0, new net.Example(), 255);

        // reading the speed if
        if (args.length > 0) {
            try {
                speed = Integer.parseInt(args[0]);
            } catch (NumberFormatException e) {
                System.out.println("the speed must be an integer\n");
                System.exit(1);
            }
        }

        // initializing reader from command line
        int i, inp_num = 0;
        String input;
        BufferedReader in_stream = new BufferedReader(new InputStreamReader(
                System.in));

        // getting a list of the available serial ports
        Vector<String> ports = network.getPortList();

        // choosing the port to connect to
        System.out.println();
        if (ports.size() > 0) {
            System.out.println("the following serial ports have been detected:");
        } 
        else {
            System.out.println("sorry, no serial ports were found on your computer\n");
            System.exit(0);
        }
        for (i = 0; i < ports.size(); ++i) {
            System.out.println("    " + Integer.toString(i + 1) + ":  " + ports.elementAt(i));
        }
        boolean valid_answer = false;
        while (!valid_answer) {
            System.out.println("enter the id (1,2,...) of the connection to connect to: ");
            try {
                input = in_stream.readLine();
                inp_num = Integer.parseInt(input);
                if ((inp_num < 1) || (inp_num >= ports.size() + 1))
                    System.out.println("your input is not valid");
                else
                    valid_answer = true;
            } catch (NumberFormatException ex) {
                System.out.println("please enter a correct number");
            } catch (IOException e) {
                System.out.println("there was an input error\n");
                System.exit(1);
            }
        }

        // connecting to the selected port
        if (network.connect(ports.elementAt(inp_num - 1), speed)) {
            System.out.println();
        } else {
            System.out.println("sorry, there was an error connecting\n");
            System.exit(1);
        }

        // asking whether user wants to mirror traffic
        System.out.println("do you want this tool to send back all the received messages?");
        valid_answer = false;
        while (!valid_answer) {
            System.out.println("'y' for yes or 'n' for no: ");
            try {
                input = in_stream.readLine();
                if (input.equals("y")) {
                    resend_active = true;
                    valid_answer = true;
                } else if (input.equals("n")) {
                    valid_answer = true;
                } else if (input.equals("q")) {
                    System.out.println("example terminated\n");
                    System.exit(0);
                }
            } catch (IOException e) {
                System.out.println("there was an input error\n");
                System.exit(1);
            }
        }

        // reading in numbers (bytes) to be sent over the serial port
        System.out.println("type 'q' to end the example");
        while (true) {
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e1) {
            }
            System.out.println("\nenter a number between 0 and 254 to be sent ('q' to exit): ");
            try {
                input = in_stream.readLine();
                if (input.equals("q")) {
                    System.out.println("example terminated\n");
                    network.disconnect();
                    System.exit(0);
                }
                inp_num = Integer.parseInt(input);
                if ((inp_num > 255) || (inp_num < 0)) {
                    System.out.println("the number you entered is not valid");
                } else {
                    int temp[] = { inp_num };
                    network.writeSerial(1, temp);   // ecriture dans le port série
                    System.out.println("sent " + inp_num + " over the serial port");
                }
            } catch (NumberFormatException ex) {
                System.out.println("please enter a correct number");
            } catch (IOException e) {
                System.out.println("there was an input error");
            }
        }
    }

    public void networkDisconnected(int id) {
        System.exit(0);
    }

    public void parseInput(int id, int numBytes, int[] message) {
        if (resend_active) {
            network.writeSerial(numBytes, message);
            System.out.print("received and sent back the following message: ");
        } else {
            System.out.print("received the following message: ");
        }
        System.out.print(message[0]);
        for (int i = 1; i < numBytes; ++i) {
            System.out.print(", ");
            System.out.print(message[i]);
        }
        System.out.println();
    }

    public void writeLog(int id, String text) {
        System.out.println("   log:  |" + text + "|");
    }

}


package net;

import gnu.io.*;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.Vector;

public class Network {
    private InputStream inputStream;
    private OutputStream outputStream;
    /**
     * The status of the connection.
     */
    private boolean connected = false;
    /**
     * The Thread used to receive the data from the Serial interface.
     */
    private Thread reader;
    private SerialPort serialPort;
    private boolean end = false;

    private Network_iface contact;
    private int divider;
    private int id;

    private int[] tempBytes;
    int numTempBytes = 0, numTotBytes = 0;

    public Network(int id, Network_iface contact, int divider) {
        this.contact = contact;
        this.divider = divider;
        if (this.divider > 255)
            this.divider = 255;
        if (this.divider < 0)
            this.divider = 0;
        this.id = id;
        tempBytes = new int[1024];
    }

    public Network(int id, Network_iface contact) {
        this(id, contact, 255);
    }

    public Network(Network_iface contact) {
        this(0, contact);
    }

    @SuppressWarnings("unchecked")
    public Vector<String> getPortList() {
        Enumeration<CommPortIdentifier> portList;
        Vector<String> portVect = new Vector<String>();
        portList = CommPortIdentifier.getPortIdentifiers();

        CommPortIdentifier portId;
        while (portList.hasMoreElements()) {
            portId = (CommPortIdentifier) portList.nextElement();
            if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
                portVect.add(portId.getName());
            }
        }
        contact.writeLog(id, "found the following ports:");
        for (int i = 0; i < portVect.size(); i++) {
            contact.writeLog(id, ("   " + (String) portVect.elementAt(i)));
        }

        return portVect;
    }

    public boolean connect(String portName) {
        return connect(portName, 115200);
    }

    public boolean connect(String portName, int speed) {
        CommPortIdentifier portIdentifier;
        boolean conn = false;
        try {
            portIdentifier = CommPortIdentifier.getPortIdentifier(portName);
            if (portIdentifier.isCurrentlyOwned()) {
                contact.writeLog(id, "Error: Port is currently in use");
            } else {
                serialPort = (SerialPort) portIdentifier.open("RTBug_network",
                        2000);
                serialPort.setSerialPortParams(speed, SerialPort.DATABITS_8,
                        SerialPort.STOPBITS_1, SerialPort.PARITY_NONE);

                inputStream = serialPort.getInputStream();
                outputStream = serialPort.getOutputStream();

                reader = (new Thread(new SerialReader(inputStream)));
                end = false;
                reader.start();
                connected = true;
                contact.writeLog(id, "connection on " + portName
                        + " established");
                conn = true;
            }
        } catch (NoSuchPortException e) {
            contact.writeLog(id, "the connection could not be made");
            e.printStackTrace();
        } catch (PortInUseException e) {
            contact.writeLog(id, "the connection could not be made");
            e.printStackTrace();
        } catch (UnsupportedCommOperationException e) {
            contact.writeLog(id, "the connection could not be made");
            e.printStackTrace();
        } catch (IOException e) {
            contact.writeLog(id, "the connection could not be made");
            e.printStackTrace();
        }
        return conn;
    }

    private class SerialReader implements Runnable {
        InputStream in;

        public SerialReader(InputStream in) {
            this.in = in;
        }

        public void run() {
            byte[] buffer = new byte[1024];
            int len = -1, i, temp;
            try {
                while (!end) {
                    if ((in.available()) > 0) {
                        if ((len = this.in.read(buffer)) > -1) {
                            for (i = 0; i < len; i++) {
                                temp = buffer[i];
                                 // adjust from C-Byte to Java-Byte
                                if (temp < 0)
                                    temp += 256;
                                if (temp == divider) {
                                    if  (numTempBytes > 0) {
                                        contact.parseInput(id, numTempBytes,
                                                tempBytes);
                                    }
                                    numTempBytes = 0;
                                } else {
                                    tempBytes[numTempBytes] = temp;
                                    ++numTempBytes;
                                }
                            }
                        }
                    }
                }
            } catch (IOException e) {
                end = true;
                try {
                    outputStream.close();
                    inputStream.close();
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
                serialPort.close();
                connected = false;
                contact.networkDisconnected(id);
                contact.writeLog(id, "connection has been interrupted");
            }
        }
    }

    public boolean disconnect() {
        boolean disconn = true;
        end = true;
        try {
            reader.join();
        } catch (InterruptedException e1) {
            e1.printStackTrace();
            disconn = false;
        }
        try {
            outputStream.close();
            inputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
            disconn = false;
        }
        serialPort.close();
        connected = false;
        contact.networkDisconnected(id);
        contact.writeLog(id, "connection disconnected");
        return disconn;
    }

    public boolean isConnected() {
        return connected;
    }

    public boolean writeSerial(String message) {
        boolean success = false;
        if (isConnected()) {
            try {
                outputStream.write(message.getBytes());
                success = true;
            } catch (IOException e) {
                disconnect();
            }
        } else {
            contact.writeLog(id, "No port is connected.");
        }
        return success;
    }

    public boolean writeSerial(int numBytes, int message[]) {
        boolean success = true;
        int i;
        for (i = 0; i < numBytes; ++i) {
            if (message[i] == divider) {
                success = false;
                break;
            }
        }
        if (success && isConnected()) {
            try {
                for (i = 0; i < numBytes; ++i) {
                        outputStream.write(changeToByte(message[i]));
                }
                outputStream.write(changeToByte(divider));
            } catch (IOException e) {
                success = false;
                disconnect();
            }
        } else if (!success) {
            // message contains the divider
            contact.writeLog(id, "The message contains the divider.");
        } else {
            contact.writeLog(id, "No port is connected.");
        }
        return success;
    }

    private byte changeToByte(int num) {
        byte number;
        int temp;
        temp = num;
        if (temp > 255)
            temp = 255;
        if (temp < 0)
            temp = 0;
        number = (byte) temp;
        return number;
    }
}

package net;

public interface Network_iface {
    public void writeLog(int id, String text);

    public void parseInput(int id, int numBytes, int[] message);

    public void networkDisconnected(int id);
}

And then I launch a J2ME MIDlet :

public class lecturePortSerieMidlet extends MIDlet implements CommandListener, Runnable {
    private Command exit=new Command("exit", Command.OK, 1);
    private Form frm = new Form("test lecture serial port");
    private TextField txt=new TextField(null, null, 10000, TextField.ANY), stat=new TextField("Status", null, 10000, TextField.ANY);;
    private Thread lire;
    private CommConnection com;
    private InputStream is;
    private InputStreamReader reader;

    public lecturePortSerieMidlet()
    {
        frm.addCommand(exit);
        frm.setCommandListener(this);
        frm.append(new TextField("Ports :", System.getProperty("microedition.commports"), 10000, TextField.ANY));
        frm.append(txt);
        frm.append(stat);
        lire = new Thread(this);
    }

    public void startApp() {
        Display.getDisplay(this).setCurrent(frm);
        lire.start();
        stat.setString("lecture port série démarrée ...");
    }

    public void pauseApp() {
    }

    public void destroyApp(boolean unconditional) {
        notifyDestroyed();
    }

    public void commandAction(Command c, Displayable d) {
        if (c == exit)
            destroyApp(true);
    }

    public void run() {
        String str = null;
        char[] buffer = new char[32];
        StringBuffer sb = new StringBuffer( );
        int count;
        try {
            com = (CommConnection) Connector.open("comm:0", Connector.READ);
            is = com.openInputStream();
            reader = new InputStreamReader(is);
            while ((count = reader.read(buffer, 0, buffer.length)) > -1)
            {
                sb.append(buffer, 0, count);
            }
            str = sb.toString();
            stat.setString("data = "+str);
            is.close();
        } catch (IOException ex) {
            stat.setString(ex.getMessage());
        }
    }
}

So the scenario is : I execute first the command line java program then I run the MIDlet. When I execute the command line java program then I chose the COM4 port identified by the program , then I enter a number value as asked by the program. Then I launch the midlet.

The problem is that the midlet shows 0 as the value of System.getProperty("microedition.commports") but the value shown in the stat field is The requested protocol does not exist comm:0 .

So why the midlet didn't work ?

0

There are 0 answers