Question

通过Calendar获取系统的当前时间后，我想把时分秒都的值都设成0，分秒成功啦，但是小时却不可以，求高手

Calendar cal = Calendar.getInstance();
cal.setTime(new Date());
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.SECOND,0);
cal.set(Calendar.MINUTE,0);

Answer 1

那就先把时间设置成明天，再设成0点
cal.add(Calendar.DATE, 1);
cal.set(Calendar.HOUR, 0);

Answer 2

cal.set(Calendar.HOUR_OF_DAY, 0); 这一项直接改为：cal.set(Calendar.HOUR, 0);

追问

还是不对，结果为2013-02-25 12:00:00，我想要的是2013-02-25 00:00:00，该怎么实现呢？？

追答

你试一试这个：cal.set(Calendar.HOUR_OF_NIGHT, 0);

Answer 3

/**
* Field number for <code>get</code> and <code>set</code> indicating the
* hour of the morning or afternoon. <code>HOUR</code> is used for the
* 12-hour clock (0 - 11). Noon and midnight are represented by 0, not by 12.
* E.g., at 10:04:15.250 PM the <code>HOUR</code> is 10.
*
* @see #AM_PM
* @see #HOUR_OF_DAY
*/
public final static int HOUR = 10;
/**
* Field number for <code>get</code> and <code>set</code> indicating the
* hour of the day. <code>HOUR_OF_DAY</code> is used for the 24-hour clock.
* E.g., at 10:04:15.250 PM the <code>HOUR_OF_DAY</code> is 22.
*
* @see #HOUR
*/
public final static int HOUR_OF_DAY = 11;
需要看你对时间格式化的规则，
DateFormat df=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
如果 是 HH 的方式 就用 cal.set(Calendar.HOUR_OF_DAY, 0)

DateFormat df=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
如果 是 hh 的方式 就用 cal.set(Calendar.HOUR, 0)

Answer 4

calendar.set(Calendar.Hour,0)就可以了