2015-07-20 54 views
1

我想知道如何查找上次在Java中8:45以来经过了多少时间。自上次“X”时钟以来经过了多少时间

ex。
时间:8:44 - > 23:59
时间8:46 - > 00.01

我现在有一个比较难看的解决方案。

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"); 
} 
+0

更容易与时期(可在Java 1.8) - [链接](https://docs.oracle.com/javase/8/docs/api/java/ time/Period.html) –

+0

我们是24小时直线对话吗?或者您是否需要考虑由[夏令时](http://stackoverflow.com/tags/dst/info)转换创建的缺失时间间隔和重复时间重叠? –

回答

0

喜欢的东西:

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())); 

} 

从本质上讲,你一定要把当前时间,设定时,分,秒和毫秒到你想要的东西,如果需要减去12或24小时。然后,您可以创建一个新的Date,这是两者之间的区别。

+0

你会想要减去24小时 - 从OP很清楚他正在处理24小时制。 – dcsohl

+0

@dcsohl - 我不确定我真的需要减法。 – OldCurmudgeon

0

如果你只是想获得日期之间的日子里,你可以使用类似:

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(); 
    } 
    } 

,如果你需要的东西更像是一个你可以使用日历逝去的几个月,做一些修正,以复杂的@ OldCurmudgeon解决方案。 (它并不适用于我的方式)

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