Java swing中的并发问题

Question

我使用SwingWorker刷新当前目录中充满文件的JList。为了防止用户多次运行刷新命令，我在运行时使用AtomicBoolean锁定命令但是在使用HashTable的put（）时，我仍然有时会遇到NullPointerException的奇怪问题，有时它会＆ ＃39;带有Matcher（）的IllegalStateException。 AtomicBoolean不足以阻止并发问题吗？

有问题的行是syntaxHash.put(file.getAbsolutePath(), m.group(1));函数

中的doInBackground()

public boolean fillWithFiles(final String EXEC_DIR) {
    if (started.compareAndSet(false, true)) {   //Lock the function
        FillWithFilesWorker worker = new FillWithFilesWorker();
        worker.execute();   //Run the worker
        return true;
    } else {
        return false;   //There is a thread in the function still
    }
}

private class FillWithFilesWorker extends SwingWorker<Void, Boolean> {

    @Override
    public Void doInBackground() {
        try {
            publish(true);  //disable JList and activate wait cursor
            if (syntaxHash != null) syntaxHash.clear();

            File currentFolder = new File(HelperWindow.EXEC_DIR);
            File[] currentRexScripts = currentFolder.listFiles(new FilenameFilter() {
                public boolean accept(File dir, String name) {
                    return name.toLowerCase().endsWith(".txt");
                }
            });

            listModel = new DefaultListModel<String>();
            for (File file : currentRexScripts) {
                listModel.addElement(file.getAbsolutePath());
            }

            final File[] tempCurrentRexScripts = currentRexScripts;
            for (File file : tempCurrentRexScripts) {
                try {
                    try (Scanner fileScanner = new Scanner(file)) {
                        while (fileScanner.hasNext()) {
                            String s = fileScanner.nextLine();
                            m = syntax.matcher(s);
                            if (m.find()) {
                                syntaxHash.put(file.getAbsolutePath(), m.group(1));
                                break;
                            }
                        }
                    }
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void done() {
        JListHelper.this.setModel(listModel);
        HelperWindow.scrollPane.setCursor(Cursor.getDefaultCursor());
        JListHelper.this.setEnabled(true);
        started.set(false);
    }

    @Override
    protected void process(List<Boolean> chunks) {
        for (Boolean chunk : chunks) {
            if (chunk) {
                HelperWindow.scrollPane.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
                JListHelper.this.setEnabled(false);
            }
        }
    }
}