Count the PDF files

import java.io.*;

class JustATest
{
    public class PdfFileFilter implements FileFilter
    {
        public boolean accept(File pathname)
        {
            if (pathname.getName().toLowerCase().endsWith(".pdf")) return true;
            return false;
        }
    }

    public static void main(String args[])
    {
        File dir = new File("Your_directory_here");
        System.out.println("Number of PDF files: " + dir.listFiles(new PdfFileFilter()).length);
    }
}