How to constrain JFileChooser to select particular number files?

问题

Using JFileChooser, I have enabled multi-selection mode by setMultiSelectionEnabled(true), but how can I set a limit so that the user can only select a particular number of text (or other) files?

public File[] fileSelect() {
    fileChooser = new JFileChooser();
    fileNameExtFilter = new FileNameExtensionFilter("Text File","txt");
    fileChooser.setCurrentDirectory(new java.io.File("."));
    fileChooser.setDialogTitle("Open Question Set");
    fileChooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
    fileChooser.setAcceptAllFileFilterUsed(false);
    fileChooser.setFileFilter(fileNameExtFilter);
    fileChooser.setMultiSelectionEnabled(true);

    if (fileChooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION)
        return fileChooser.getSelectedFiles();
    else
        return null;
}

回答1:

Several approaches are possible:

Create a custom FileChooserUI by subclassing BasicFileChooserUI and limit the selection in your implementation of the nested class SelectionListener.
Create a custom file browser, as shown here, and limit the selection in the relevant listener.
Use the existing FileChooser and present a dialog when the selection exceeds three; consider using a JTable containing checkboxes as shown here.
Use separate chooser panels, as shown here for two files via createPathPanel().

The best choice and exact details will depend on the use case.

来源：https://stackoverflow.com/questions/32523630/how-to-constrain-jfilechooser-to-select-particular-number-files

标签

java

swing

jfilechooser