如何将Java中的文件选择器限制为特定文件? [英] How to restrict file choosers in java to specific files?

问题描述

private void openMenuActionPerformed(java.awt.event.ActionEvent evt) {
    
    DBmanager db = new DBmanager();
    if (!db.getCurrentUser().equals("Admin")) {
        JOptionPane.showMessageDialog(this, "You are Not Allowed to Run Applications");
        JFileChooser fileChooser = new JFileChooser();
        fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
        fileChooser.addChoosableFileFilter(new FileNameExtensionFilter("PDF Documents", "pdf"));
        fileChooser.addChoosableFileFilter(new FileNameExtensionFilter("MS Office Documents", "docx", "xlsx", "pptx"));
        fileChooser.addChoosableFileFilter(new FileNameExtensionFilter("Images", "jpg", "png", "gif", "bmp"));
        fileChooser.setAcceptAllFileFilterUsed(false);
        int returnVal = fileChooser.showOpenDialog(this);

        if (returnVal == JFileChooser.APPROVE_OPTION) {
            File file = fileChooser.getSelectedFile();

            if (Desktop.isDesktopSupported()) {
                try {
                    Desktop.getDesktop().open(file);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    } else if (db.getCurrentUser().equals("Admin")) {
        JFileChooser fileChooser = new JFileChooser();
        fileChooser.setAcceptAllFileFilterUsed(true);
        int returnVal = fileChooser.showOpenDialog(this);
        if (returnVal == JFileChooser.APPROVE_OPTION) {
            File file = fileChooser.getSelectedFile();
            if (Desktop.isDesktopSupported()) {
                try {
                    Desktop.getDesktop().open(file);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }// TODO add your handling code here:
}

我正在尝试通过设置fileChooser.setAcceptAllFileFilterUsed(false);来过滤文件过滤器中的文件. 所有文件"该选项将从FileChooser中消失，但所有文件仍然可见，除非您从PDF文档，ms Office或图像中选择一个选项.打开文件选择器时，我只想拥有3个自定义过滤器.

I am trying to filter files in a file filter by setting fileChooser.setAcceptAllFileFilterUsed(false);. The "all files" option disappears from the FileChooser but all files remain visible unless you select an option from PDF documents,ms Office or images. I want to have only my 3 custom filters upon opening the file chooser.

推荐答案

例如，如果您要过滤JFileChooser以严格显示最常见的图像文件，则可以使用以下方法:

For example, if you want to filter your JFileChooser to strictly display most commonly found image files, you would use something like this:

FileNameExtensionFilter filter = new FileNameExtensionFilter("Image Files", "jpg", "png", "gif", "jpeg");
JFileChooser fileChooser = new JFileChooser();
fileChooser.setFileFilter(filter);

第一个参数是描述(选择时会在底部显示)，第二个参数是非正式文件扩展名.

The first argument is the description (what gets displayed upon selection at the bottom) and the second argument are the informal file extensions.

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