Touch a file: set File Last Modified Time

 
import java.io.File;
import java.util.Date;

class Touch {
  public static void main(String[] args) {
    String[] names = new File(".").list();

    Date current = new Date();

    for (int i = 0; i < names.length; i++) {
      File f = new File(names[i]);
      f.setLastModified(current.getTime());
    }
  }
}