Image Viewer - ImageFilter

import java.io.File;

import javax.swing.filechooser.FileFilter;;

public class ImageFilter extends FileFilter {
    public static String getExtension( File f ) {
        String ext = null;
        String s = f.getName();
        int i = s.lastIndexOf( '.' );

        if( i > 0 &&  i < s.length() - 1 ) {
            ext = s.substring( i+1 ).toLowerCase();
        }

        return( ext );
    }

    public boolean accept( File f ) {
        boolean r = false;

        if( f.isDirectory() ) {
            r = true;
        }
        else {
            String extension = getExtension( f );
            if( extension != null ) {
                r = extension.equals( "png" ) ||
                    extension.equals( "jpeg" ) ||
                    extension.equals( "jpg" ) ||
                    extension.equals( "tif" ) ||
                    extension.equals( "tiff" ) ||
                    extension.equals( "gif" );
            }
        }

        return( r );
    }

    public String getDescription() {
        return( "Image Files" );
    }
}