Prva zad operativni(FileFilter)

package filter;


import java.io.File;
import java.io.FilenameFilter;

public class Filter{
   public static void main(String[] args) {
      int i=0,zbir=0;
      float prosGol;
      File f = null;
      File[] filovi;

      try{
         // create new file
         f = new File("C:\\");

         // create new filename filter
         FilenameFilter fileNameFilter = new FilenameFilter() {

            @Override
            public boolean accept(File dir, String name) {
               if(name.lastIndexOf('.')>0)
               {
                  // get last index for '.' char
                  int lastIndex = name.lastIndexOf('.');

                  // get extension
                  String str = name.substring(lastIndex);

                  // match path name extension
                  if(str.equals(".txt"))
                  {
                     return true;
                  }
               }
               return false;
            }
         };
         // returns pathnames for files and directory
          filovi = f.listFiles(fileNameFilter);

         // for each pathname in pathname array
         for(File k:filovi)
         {
             i++;
             zbir +=k.length();
            // prints file and directory paths

             System.out.println(k);
         }
         prosGol=(float)zbir/i;
         System.out.println("Prosecna golemina"+prosGol);
      }catch(Exception e){
         // if any error occurs
         System.out.println("Error");
      }
   }
}