import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import java.io.*;
import java.net.URL;

abstract class SuffixAwareFilter 
			   extends javax.swing.filechooser.FileFilter {
	public String getSuffix(File f) {
		String s = f.getPath(), suffix = null;
	    int i = s.lastIndexOf('.');

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

		return suffix;
	}
	public boolean accept(File f) {
		return f.isDirectory();
	}
}