SwingWorker problem!!! How can I run it 2 times or more?

Question

Hello!!
I am new in Java. I use the following code:
SwingWorker SWorker = new SwingWorker<String, Void>()
   public String doInBackground() {
   return CargarInformacion();
public void done() {
   try {
      JTextAreaReport.append(get());
   } catch(InterruptedException ie)
      System.out.println(ie.toString());
   } catch(java.util.concurrent.ExecutionException ee)
      System.out.println(ee.toString());
private String CargarInformacion()
   try
      in = new BufferedReader(new FileReader(file));
      <read file...>
   return StrMessage;
}The problem is that when this code runs for the first time it works perfect!!! but I need to use it several times with other file names. In the java docs I found the following text:
"SwingWorker is only designed to be executed once. Executing a SwingWorker more than once will not result in invoking the doInBackground method twice."
How can I resolve this?
thank's.
David.
Edited by: davigre on Oct 1, 2008 8:42 PM

Answer 1

I am trying to do this as well. For some reason, it is not working for me. I have a class "Task" that extends Swingworker with a doInBackground() and done(). Each time I click "submit" I create a new "Task" and call task.execute(). But the second time around, the doInBackground() never gets called. Can someone help me out? Here are a couple of the relevant functions.
Thanks
Mike
Here is where the thread is started:
public void readDataLogger() {
        jButton.setEnabled(false);
        jBox.setEnabled(false);
        String deleteData = JOptionPane.showInputDialog("Would you like to erase all the data off this logger after it is downloaded? (y/n)");
        if (deleteData == null || deleteData.equalsIgnoreCase("n") || deleteData.equalsIgnoreCase("no")) {
            // user clicked cancel or typed n/no
        } else if (deleteData.equalsIgnoreCase("y") || deleteData.equalsIgnoreCase("yes")) {
            erase = true;
        routeNum.setText("Route Num: " + (String) jBox.getSelectedItem());
        waiting.setText("Please wait a moment...");
        Thread stepper = new BarThread(progressBar);
        stepper.start();
        this.add(progressBar);
        Task task = new Task();
        task.execute();
    }And the thread classes:
class BarThread extends Thread {
        JProgressBar progressBar;
        public BarThread(JProgressBar bar) {
            progressBar = bar;
        public void run() {
    class Task extends SwingWorker<Void, Void>{
        boolean wrongPort;
        long timeGoneBy = 0;
         * Main task. Executed in background thread.
        public Void doInBackground() {
            wrongPort = true;
            try {
                logWriter.append("starting new thread");
                logWriter.flush();
            } catch (IOException ex) {
                Logger.getLogger(DDAGPS.class.getName()).log(Level.SEVERE, null, ex);
            Runtime rt = Runtime.getRuntime();
            File propertiesFile = new File("port.properties");
            Properties properties = new Properties();
            String command = "";
            int portTry = 0;
            boolean propPort = false;
            if (propertiesFile.exists()) {
                try {
                    properties.load(new FileInputStream("port.properties"));
                } catch (IOException ex) {
                    ex.printStackTrace();
                if (properties.containsKey("port")) {
                    portTry = Integer.parseInt((String) properties.get("port"));
                    try {
                        logWriter.append("port from properties: " + portTry + "\r\n");
                        logWriter.flush();
                    } catch (IOException ex) {
                        ex.printStackTrace();
                    command = baseDir + "GPSBabel/gpsbabel.exe -p \"\" -w -t -i mtk";
                    if (erase) {
                        command += ",erase";
                    command += " -f com" + portTry + ": -o gpx,gpxver=1.0 -F " + baseDir + "Temp/" + jBox.getSelectedItem() + "-" + numbLoggers + ".gpx";
                    launching.setText("trying it on COM" + portTry);
                    try {
                        logWriter.append("command using port from props: " + command + "\r\n");
                        logWriter.flush();
                        Process p = rt.exec(command);
                        File bin = new File(baseDir + "data.bin");
                        boolean fileExists = false;
                        double time = 0.0;
                        while (!procDone(p) && !fileExists && time < 10) {
                            logWriter.append("waiting and looking for bin file: " + time + "\r\n");
                            logWriter.flush();
                            Thread.sleep(200);
                            time += .2;
                            if (bin.exists() && bin.length() > 0) {
                                wrongPort = false;
                                launching.setText("it worked on COM" + portTry + ", building data file...");
                                propPort = true;
                                fileExists = true;
                        if (!fileExists) {
                            logWriter.append("it did not work using the port from the properties file");
                            logWriter.flush();
                    } catch (IOException ex) {
                        try {
                            logWriter.append("error: " + ex.getMessage() + " trying to use GPSBabel with port from properties file\r\n");
                            logWriter.flush();
                        } catch (IOException ex1) {
                            ex1.printStackTrace();
                    } catch (InterruptedException ex) {
                        ex.printStackTrace();
            //if (!propPort) {
                try {
                    Process p = rt.exec("mode.com");
                    String s = null;
                    ArrayList<Integer> ports = new ArrayList<Integer>();
                    BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));
                    logWriter.append("Here is the standard output of the command:\r\n");
                    logWriter.flush();
                    int lines = 0;
                    int po = -1;
                    while ((s = stdInput.readLine()) != null) {
                        String port = "";
                        logWriter.append("line: " + s + "\r\n");
                        logWriter.flush();
                        if (lines > 0) {
                            if (s.contains("Baud") && s.contains("115200")) {
                                logWriter.append("adding port: " + po + "\r\n");
                                logWriter.flush();
                                ports.add(po);
                            lines--;
                        if (s.startsWith("Status for device COM")) {
                            port = s.substring(s.indexOf("M") + 1, s.indexOf(":"));
                            po = Integer.parseInt(port);
                            lines = 2;
                    stdInput.close();
                    portTry = 0;
                    logWriter.append("wrongPort: " + wrongPort);
                    logWriter.flush();
                    while (portTry < ports.size() && wrongPort) {
                        command = baseDir + "GPSBabel/gpsbabel.exe -p \"\" -w -t -i mtk";
                        if (erase) {
                            command += ",erase";
                        command += " -f com";
                        command += ports.get(portTry) + ": -o gpx,gpxver=1.0 -F " + baseDir + "Temp/" + jBox.getSelectedItem() + "-" + numbLoggers + ".gpx";
                        System.out.println("command: " + command);
                        Long currentTime1 = System.currentTimeMillis();
                        launching.setText("trying it on COM" + ports.get(portTry));
                        logWriter.append("command: " + command + "\r\n");
                        logWriter.flush();
                        p = rt.exec(command);
                        boolean fileExists = false;
                        while (!procDone(p) && wrongPort && !fileExists) {
                            Thread.sleep(100);
                            long currentTime2 = System.currentTimeMillis();
                            timeGoneBy = (currentTime2 - currentTime1);
                            Long seconds = timeGoneBy / 1000;
                            int hundreds = (int) (timeGoneBy / 100) % 10;
                            timer.setText(seconds + "." + hundreds + " s");
                            logWriter.append("still working: " + seconds + " seconds\r\n");
                            logWriter.flush();
                            File bin = new File(baseDir + "data.bin");
                            if (!(bin.exists() && bin.length() > 0)) {
                                wrongPort = true;
                            } else {
                                logWriter.append("bin exists: " + bin.exists() + "\r\n");
                                logWriter.flush();
                                //File port = new File(baseDir + "port.properties");
                                //FileWriter fw = new FileWriter(port);
                                //fw.append("port=" + String.valueOf((ports.get(portTry))));
                                //fw.flush();
                                //fw.close();
                                launching.setText("it worked on COM" + ports.get(portTry) + ", building data file...");
                                wrongPort = false;
                            if (seconds > 15) {
                                takeAWhile.setText("This could take a minute or two depending on how much data you have to pull off.");
                            File file = new File(baseDir + "Temp/" + jBox.getSelectedItem() + "-" + numbLoggers + ".gpx");
                            if (file.exists()) {
                                fileExists = true;
                            logWriter.append("wrongPort: " + wrongPort + "\r\n");
                            logWriter.flush();
                            logWriter.append("fileExists: " + fileExists + "\r\n");
                            logWriter.flush();
                            logWriter.append("procDone: " + procDone(p) + "\r\n");
                            logWriter.flush();
                        portTry++;
                } catch (IOException ex) {
                    ex.printStackTrace();
                } catch (InterruptedException ex) {
                    ex.printStackTrace();
            return null;
        private boolean procDone(Process p) {
            try {
                int v = p.exitValue();
                return true;
            } catch (IllegalThreadStateException e) {
                return false;
         * Executed in event dispatch thread
        public void done() {
            try {
                logWriter.append("in done!\r\n");
                logWriter.append("wrongPort: " + wrongPort);
                logWriter.flush();
            } catch (IOException ex) {
                Logger.getLogger(DDAGPS.class.getName()).log(Level.SEVERE, null, ex);
            launching.setText("");
            ddagps.repaint();
            File bin = new File(baseDir + "data.bin");
            if (wrongPort) {
                //wrongPort = false;
                String message = "Something went wrong.  Please make sure the device is turned on and replug the " +
                        "device into the USB port and hit OK.";
                int response = redo(message);
                if (response == 1) {
                    System.exit(0);
                } else {
                    timer.setText("");
                    readDataLogger();
            } else {
                try {
                    logWriter.append("i am in done's else!\r\n");
                    logWriter.flush();
                } catch (IOException ex) {
                    Logger.getLogger(DDAGPS.class.getName()).log(Level.SEVERE, null, ex);
                launching.setText("creating gpx file");
                ddagps.repaint();
                File file = new File(baseDir + "Temp/" + jBox.getSelectedItem() + "-" + numbLoggers + ".gpx");
                while (!file.exists()) {
                    try {
                        Thread.sleep(100);
                    } catch (InterruptedException ex) {
                        ex.printStackTrace();
                //System.out.println("f1 does not exist");
                numbLoggers++;
                ddagps.remove(progressBar);
                takeAWhile.setText("");
                Toolkit.getDefaultToolkit().beep();
                jBox.setEnabled(true);
                jButton.setEnabled(true);
                waiting.setText("Done!\n");
                String moreDevices = JOptionPane.showInputDialog("Do you have any more devices to enter in? (y/n)");
                if (moreDevices == null) {
                    // user clicked cancel
                } else if (moreDevices.equalsIgnoreCase("y") || moreDevices.equalsIgnoreCase("yes")) {
                    JOptionPane.showMessageDialog(null, "Hit OK when the next logger is plugged in.");
                    timer.setText("");
                    bin.delete();
                    readDataLogger();
                } else if (moreDevices.equalsIgnoreCase("n") || moreDevices.equalsIgnoreCase("no")) {
                    launching.setText("Merging files...");
                    ddagps.repaint();
                    int numb = numbLoggers - 1;
                    File f = new File(baseDir + "Temp/" + jBox.getSelectedItem() + "-" + numb + ".gpx");
                    while (!f.exists()) {
                        try {
                            Thread.sleep(200);
                        } catch (InterruptedException ex) {
                            ex.printStackTrace();
                    //System.out.println("f2 does not exist");
                    //System.out.println("found " + f.getName());
                    ParseAndCombineKMLs pack = new ParseAndCombineKMLs(numbLoggers, jBox.getSelectedItem());
                    if (pack.parseAndCombine()) {
                        f = new File(baseDir + "Output/" + jBox.getSelectedItem() + ".kml");
                        while (!f.exists()) {
                            try {
                                Thread.sleep(100);
                            } catch (InterruptedException ex) {
                                ex.printStackTrace();
                        //System.out.println("f3 does not exist");
                        Uploader up = new Uploader(upload);
                        if (up.pushFile(baseDir + "Output/" + jBox.getSelectedItem() + ".kml")) {
                            launching.setText("Upload Successful");
                            Runtime rt = Runtime.getRuntime();
                            try {
                                rt.exec("C:/Program Files/Mozilla Firefox/firefox.exe " + view + "?route=" + jBox.getSelectedItem());
                                bin = new File(baseDir + "data.bin");
                                bin.delete();
                                launching.setText("Launching browswer with your data...");
                            } catch (IOException ex) {
                                ex.printStackTrace();
                    try {
                        logWriter.close();
                    } catch (IOException ex) {
                        ex.printStackTrace();
    }Edited by: dmikester1 on Nov 5, 2008 8:50 AM