[java] How to get a list of current open windows/process with Java?

This is my code for a function that gets the tasks and gets their names, also adding them into a list to be accessed from a list. It creates temp files with the data, reads the files and gets the task name with the .exe suffix, and arranges the files to be deleted when the program has exited with System.exit(0), it also hides the processes being used to get the tasks and also java.exe so that the user can't accidentally kill the process that runs the program all together.

private static final DefaultListModel tasks = new DefaultListModel();

public static void getTasks()
{
    new Thread()
    {
        @Override
        public void run()
        {
            try 
            {
                File batchFile = File.createTempFile("batchFile", ".bat");
                File logFile = File.createTempFile("log", ".txt");
                String logFilePath = logFile.getAbsolutePath();
                try (PrintWriter fileCreator = new PrintWriter(batchFile)) 
                {
                    String[] linesToPrint = {"@echo off", "tasklist.exe >>" + logFilePath, "exit"};
                    for(String string:linesToPrint)
                    {
                        fileCreator.println(string);
                    }
                    fileCreator.close();
                }
                int task = Runtime.getRuntime().exec(batchFile.getAbsolutePath()).waitFor();
                if(task == 0)
                {
                    FileReader fileOpener = new FileReader(logFile);
                    try (BufferedReader reader = new BufferedReader(fileOpener))
                    {
                        String line;
                        while(true)
                        {
                            line = reader.readLine();
                            if(line != null)
                            {
                                if(line.endsWith("K"))
                                {
                                    if(line.contains(".exe"))
                                    {
                                        int index = line.lastIndexOf(".exe", line.length());
                                        String taskName = line.substring(0, index + 4);
                                        if(! taskName.equals("tasklist.exe") && ! taskName.equals("cmd.exe") && ! taskName.equals("java.exe"))
                                        {
                                            tasks.addElement(taskName);
                                        }
                                    }
                                }
                            }
                            else
                            {
                                reader.close();
                                break;
                            }
                        }
                    }
                }
                batchFile.deleteOnExit();
                logFile.deleteOnExit();
            } 
            catch (FileNotFoundException ex) 
            {
                Logger.getLogger(Functions.class.getName()).log(Level.SEVERE, null, ex);
            } 
            catch (IOException | InterruptedException ex) 
            {
                Logger.getLogger(Functions.class.getName()).log(Level.SEVERE, null, ex);
            }
            catch (NullPointerException ex)
            {
                // This stops errors from being thrown on an empty line
            }
        }
    }.start();
}

public static void killTask(String taskName)
{
    new Thread()
    {
        @Override
        public void run()
        {
            try 
            {
                Runtime.getRuntime().exec("taskkill.exe /IM " + taskName);
            } 
            catch (IOException ex) 
            {
                Logger.getLogger(Functions.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    }.start();
}