JFileChooser showSaveDialog在文件名為空或為空時顯示錯誤消息

Question

該代碼可用於檢查非空/空格的AbsolutePath，但不適用於AbsolutePath僅為空白的情況。 單擊保存不執行任何操作，並且JFileChooser停留在showSaveDialog（）中。

當用戶嘗試使用空白文件名保存文件時，我想顯示JOptionPane錯誤消息。

    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(). 正如@camickr上面所說的： 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. 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. 。