FileFilter  
There are several file filtering classes and interfaces in Java..

JFileChooser  
The javax.swing.JFileChooser class is used to create file choosers for selecting files or directories to open or save..

JOptionPane - Simple Dialogs  
Here are two useful static methods from javax.swing.JOptionPane..

JOptionPane - More Dialogs  
You will learn some more useful static methods from javax.swing.JOptionPane.

The Dialog boxes  
There are several ways to build dialog boxes..