java.lang.Object
   |
   +----java.awt.Component
           |
           +----java.awt.Container
                   |
                   +----java.awt.Window
                           |
                           +----java.awt.Dialog
                                   |
                                   +----java.awt.FileDialog
 public class FileDialog
  
 extends Dialog
The FileDialog class displays a dialog window from which the user can select a file.
Since it is a modal dialog, when the application calls its show method to display the dialog, it blocks the rest of the application until the user has chosen a file.