java代码如何将“小时、分钟、秒”设置为零呢?

实现思路:
    定义一个Calendar对象
	然后将对象中的小时，分，秒设置为零
	即可到达相应的效果

public class Main
{
   static SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    public static void main(String[] args)
    {
        Calendar now = Calendar.getInstance();
        now.set(Calendar.HOUR, 0);
        now.set(Calendar.MINUTE, 0);
        now.set(Calendar.SECOND, 0);
        System.out.println(sdf.format(now.getTime()));
        now.set(Calendar.HOUR_OF_DAY, 0);
        System.out.println(sdf.format(now.getTime()));
    }
}