Question

我想知道如何找到自Java上次8:45以来已经过了多少时间。

离。
时间：8：44 - ＆gt; 23:59
时间8:46 - ＆gt; 00.01

我现在有一个相当难看的解决方案。

if (calendar.get(Calendar.HOUR_OF_DAY) >= 8) {
    if (calendar.get(Calendar.MINUTE) >= 45 || calendar.get(Calendar.HOUR_OF_DAY) > 9) {
        System.out.println("it between 8:45 and 00:00");
    }
}
else {
    System.out.println("its between 00:00 and 8:45");
}

Answer 1

类似的东西：

public void test() {
    Calendar c = Calendar.getInstance();
    Calendar eightFortyFive = Calendar.getInstance();
    eightFortyFive.set(Calendar.HOUR, 8);
    eightFortyFive.set(Calendar.MINUTE, 45);
    eightFortyFive.set(Calendar.SECOND, 0);
    eightFortyFive.set(Calendar.MILLISECOND, 0);
    // You might not need to do this or you may need to use -24.
    if (eightFortyFive.after(c)) {
        eightFortyFive.add(Calendar.HOUR, -12);
    }
    System.out.println("Time since " + eightFortyFive.getTime() + " = " + new Date(c.getTimeInMillis() - eightFortyFive.getTimeInMillis()));

}

基本上你必须花费当前时间，将小时，分钟，秒和毫秒设置为你想要的，并在必要时减去12或24小时。然后，您可以创建一个新的Date，这是两者之间的差异。

Answer 2

如果您只是希望到达日期之间的日子，可以使用以下内容：

public static void main(String[] args) {
    long initial = getTime("20-jul-2015 11:09:25"); /*you use System.currentTimeMillis() at the beginning*/
    long finalTime = getTime("21-jul-2016 15:21:26"); /*you use System.currentTimeMillis() at the capture of final time.*/
    printElapsedTime(initial, finalTime);
  }

  private static void printElapsedTime(long initial, long finalTime) {
    long lapse = finalTime - initial; 
    long secs = (lapse/(1000))%60;
    long mins = lapse/(1000*60)%60;
    long hrs = lapse/(1000*60*60)%24;
    long days = lapse/(1000*60*60*24);

    StringBuilder lapseMsg = new StringBuilder("Elapsed time since ").append(new Date(initial)).append(" to " + new Date(finalTime)).append(":\r\n");
    lapseMsg.append(days).append(" Days, ").append(hrs).append(" Hours, ").append(mins).append(" Minutes, ").append(secs).append(" seconds");
    System.out.println(lapseMsg.toString());
  }

  /*just used to get any date to test.*/
  private static long getTime(String date) {
    DateFormat format = DateFormat.getDateTimeInstance();
    try {
      return format.parse(date).getTime();
    } catch (ParseException e) {
      throw new RuntimeException();
    }
  }

如果您需要更复杂的内容，例如获取已失效的月份，您可以使用日历，对@OldCurmudgeon解决方案进行一些修复。（它不像我那样对我有用）

自上一次“X”时钟以来经过了多少时间

2 个答案: