JFileChooser showSaveDialog在文件名为空或为空时显示错误消息

Question

该代码可用于检查非空/空格的AbsolutePath，但不适用于AbsolutePath仅为空白的情况。单击保存不执行任何操作，并且JFileChooser停留在showSaveDialog（）中。

当用户尝试使用空白文件名保存文件时，我想显示JOptionPane错误消息。

    try {
        JFileChooser chooser = new JFileChooser("./");
        FileNameExtensionFilter filter = new FileNameExtensionFilter("files (txt)", "txt");
        chooser.setFileFilter(filter);
        chooser.setMultiSelectionEnabled(false);
        chooser.setSelectedFile(new File(fileName));

        int value = chooser.showSaveDialog(this);
        if (value == JFileChooser.APPROVE_OPTION) {
            String filename = chooser.getSelectedFile().getAbsolutePath();
            if (chooser.getSelectedFile().getName().trim().equals("")
                    || !chooser.getSelectedFile().getName().endsWith(".txt")
                    || chooser.getSelectedFile().getName().replaceAll(".txt", "").trim().equals("")) {
                throw new IllegalArgumentException();
            }
            saveFile(filename);
        }

    } catch (IllegalArgumentException e) {
        JOptionPane.showMessageDialog(this, "Fail! File was not saved", "Error", JOptionPane.ERROR_MESSAGE);
    }

Answer 1

Clicking save does nothing and the JFileChooser stays in showSaveDialog().，如@camickr所说：this is the built in functionality of the JFileChooser and has nothing to do with your code. The file chooser doesn't close unless you enter a filename (and click Save) or use the Cancel button.。