计算两个日历日期之间的工作日差异

Question

我正在尝试查找两个日期之间的工作日计数（必须忽略周末和时间）。我正在使用以下功能来做到这一点。但它会针对多种情况给出错误的结果，例如开始日期是否在周末或结束日期是否在周末。这是一个演示示例，可以额外计算一天。

2018-03-08 00:00:00.0 and 2018-04-22 01:37:29.887

计数返回 32（应该是 31，它也在考虑 23-04-2018）。请提供一些完美的 solution/approach 来做同样的事情。

private static int calculateDuration(Date startDate, Date endDate)
{
  Calendar startCal = Calendar.getInstance();
  startCal.setTime(startDate);
  startCal.set( Calendar.HOUR_OF_DAY, 0 );
  startCal.set( Calendar.MINUTE, 0 );
  startCal.set( Calendar.SECOND, 0 );
  startCal.set( Calendar.MILLISECOND, 0 );
  Calendar endCal = Calendar.getInstance();
  endCal.setTime(endDate);
  endCal.set( Calendar.HOUR_OF_DAY, 0 );
  endCal.set( Calendar.MINUTE, 0 );
  endCal.set( Calendar.SECOND, 0 );
  endCal.set( Calendar.MILLISECOND, 0 );
  int workDays = 0;

  if (startCal.getTimeInMillis() > endCal.getTimeInMillis())
  {
    startCal.setTime(endDate);
    endCal.setTime(startDate);
  }

  do
  {
    startCal.add(Calendar.DAY_OF_MONTH, 1);
    System.out.println("************"+Calendar.DAY_OF_WEEK);
    System.out.println("Before weekend condition"+Calendar.DAY_OF_WEEK+"Workdays="+workDays);

    if (startCal.get(Calendar.DAY_OF_WEEK) != Calendar.SATURDAY && startCal.get(Calendar.DAY_OF_WEEK) != Calendar.SUNDAY)
    {
      workDays++;
        System.out.println("This day picked "+startCal.getTime()+"Workdays="+workDays);


    }
  }
  while (startCal.getTimeInMillis() <= endCal.getTimeInMillis());
System.out.println("Final workdays count for  "+startDate+" and "+endDate+" is"+workDays);

  return workDays;
}

我尝试了多种解决方案，但除了提到的情况外，这个效果很好。

Answer 1

我高度推荐使用Java 9及更高版本中的java.time.LocalDate::datesUntil方法。只需几行即可计算，而不必使用 Calendar:

var startDate = LocalDate.parse("2018-03-08");
var endDate = LocalDate.parse("2018-04-22");

var numWeekDays = startDate.datesUntil(endDate)
                           .map(LocalDate::getDayOfWeek)
                           .filter(d -> d != DayOfWeek.SATURDAY && d != DayOfWeek.SUNDAY)
                           .count();

System.out.println(numWeekDays);

输出：

计算两个日历日期之间的工作日差异

Calculating workday difference between two calendar dates

java

date

weekday

date-difference