Java copy.

import java.io.File;

public class renamer
{

 public static void main(String[] args)
{

  // Directory path here
  String path = "C:\\Users\\wildcat\\Desktop\\renameinput";

  String files;
  File folder = new File(path);
  File[] listOfFiles = folder.listFiles();

  //Find files to process, list them.
  for (int i = 0; i < listOfFiles.length; i++)
  {

   if (listOfFiles[i].isFile())
   {
   files = listOfFiles[i].getName();
       if (files.endsWith(".txt") || files.endsWith(".TXT"))
       {
          System.out.println(files);
        }
     }
  }

  for (int i = 0; i < listOfFiles.length; i++)
  {
          File oldFile = new File(listOfFiles[i].getName());
          System.out.println(listOfFiles[i].getName());
          boolean happen = oldFile.renameTo(new File("C:\\Users\\wildcat\\Desktop\\renameoutput" + oldFile.getName()));
          System.out.println(happen);
  }

}
}