By default, hidden files are not shown in a file chooser dialog. 
    JFileChooser chooser = new JFileChooser();
    
    // By default, hidingEnabled is true
    boolean hidingEnabled = chooser.isFileHidingEnabled();
    
    // Display hidden files
    chooser.setFileHidingEnabled(false);
    
    // Show the dialog; wait until dialog is closed
    chooser.showOpenDialog(frame);