Question

可能重复：
Calculating the Difference Between Two Java Date Instances

如何获取Java中两个日期之间的天数？

最好的方法是什么？这是我得到的，但它不是最好的：

public static ConcurrentHashMap<String, String> getWorkingDaysMap(int year, 
    int month, int day){
        int totalworkingdays=0,noofdays=0;
        String nameofday = "";
        ConcurrentHashMap<String,String> workingDaysMap = 
            new ConcurrentHashMap<String,String>();
        Map<String,String> holyDayMap = new LinkedHashMap<String,String>();
        noofdays = findNoOfDays(year,month,day);

        for (int i = 1; i <= noofdays; i++) {
            Date date = (new GregorianCalendar(year,month - 1, i)).getTime();
            // year,month,day
            SimpleDateFormat f = new SimpleDateFormat("EEEE");
            nameofday = f.format(date);

            String daystr="";
            String monthstr="";

            if(i<10)daystr="0";
            if(month<10)monthstr="0";

            String formatedDate = daystr+i+"/"+monthstr+month+"/"+year;

            if(!(nameofday.equals("Saturday") || nameofday.equals("Sunday"))){
                workingDaysMap.put(formatedDate,formatedDate);
                totalworkingdays++;
            }
        }

        return workingDaysMap;
    }

public static int findNoOfDays(int year, int month, int day) {
        Calendar calendar = Calendar.getInstance();
        calendar.set(year, month - 1, day);
        int days = calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
        return days;
    }

Answer 1

我通常做这样的事情：

final long DAY_IN_MILLIS = 1000 * 60 * 60 * 24;

int diffInDays = (int) ((date1.getTime() - date2.getTime())/ DAY_IN_MILLIS );

不需要外部lib，也很简单

更新：刚刚看到你想要“日期”，类似的方法适用：

//assume date1 < date2

List<Date> dateList = new LinkedList<Date>();
for (long t = date1.getTime(); t < date2.getTime() ; t += DAY_IN_MILLIS) {
  dateList.add(new Date(t));
}

当然，使用JODA时间或其他lib可能会让您的生活更轻松，但我认为目前的方式难以实现

更新：重要提示！这仅适用于没有夏令时或类似调整的时区，或者您对“天数差异”的定义实际上意味着“24小时单位差异”

如何获取java中两个日期之间的天数？

1 个答案: