[b]How to Use the Class:[/b] // Create file chooser final JFileChooser fChooser = new JFileChooser(new File("MyFile.txt")); fChooser.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES); // Show fChooser.setFileFilter(new ChooserFilter("txt")); nRet = fChooser.showSaveDialog(this); if (nRet == JFileChooser.APPROVE_OPTION) { // DO Something } [b]The Class:[/b] // Imports import java.io.*; import javax.swing.filechooser.FileFilter; public class ChooserFilter extends FileFilter { // Declare variables // -- Private private String m_strExtention = null; public ChooserFilter(String strExt) { m_strExtention = strExt; } public boolean accept(File f) { if (f.isDirectory()) { return true; } String s = f.getName(); int i = s.lastIndexOf('.'); if (i > 0 && i < s.length() - 1) { String extension = s.substring(i + 1).toLowerCase(); if (m_strExtention.equals(extension)) { return true; } else { return false; } } return false; } public String getDescription() { return ""; } }