import java.io.File;
 
public class RenameFile {
 
 public static void main(String[] args) {
 
  File file = new File("C:\\MyFile.txt");
  File newFile = new File("C:\\MyFileRenamed.txt");
  file.renameTo(newFile);
 }
}

This code will take the file 'MyFile.txt' and rename it 'MyFileRenamed.txt'

This can be used to rename any file on your computer.