.....
 public   class  FileListFilter  implements  FileNameFilter {

 private  String name;
 private  String extention;

 public  FileListFilter(String name,String extention )
  {
   this .name = name;
   this .extention = extention;
   }
   
    public   boolean  accept (File directory, String filename)
     {
        boolean  fileOK = true;
         
           if (name !=  null )
            fileOK &= filename.startsWith(name);
          
         if (extention !=  null )
           fileOK &= filename.endsWith('.' + extention );
       
        return  fileOK;
    }

}