Java Data Type - 如何获取从现在开始5秒钟的时间

import java.util.Calendar;

public class Main {

  public static void main(String[] args) {
    Calendar now = Calendar.getInstance();
    System.out.println("Current time : " + now.get(Calendar.HOUR_OF_DAY) + ":"
        + now.get(Calendar.MINUTE) + ":" + now.get(Calendar.SECOND));

    now.add(Calendar.SECOND, 100);
    System.out.println("New time after adding 100 seconds : " + now.get(Calendar.HOUR_OF_DAY) + ":"
        + now.get(Calendar.MINUTE) + ":" + now.get(Calendar.SECOND));
  }
}