如何在Java中的两个日期之间获得星期六和星期日

Question

StartDate:  2016-05-8 20:16:00;
EndDate:    2016-05-30 20:16:00;


     public int saturdaysundaycount(Date d1, Date d2) {
                Calendar c1 = Calendar.getInstance();
                c1.setTime(d1);

                Calendar c2 = Calendar.getInstance();
                c2.setTime(d2);

                int sundays = 0;
                int saturday = 0;

                while (c1.after(c2)) {
                    if (c2.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY || c2.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY)
                        sundays++;
                    saturday++;
                    c2.add(Calendar.DATE, 1);
                    c2.add(Calendar.DATE, 1);
                }
                System.out.println(sundays);

                return saturday + sundays;
            }

在这个函数中，我试图获取两个日期之间周六和周日的总数。但是当我通过日期时，结果为零。请指出错误并提出更正建议。

Answer 1

不建议编写完整的程序，但由于您付出了努力，这里似乎在我的系统上运行并返回7.

public class CountWeekends {

    public static void main(String[] args){

        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
        int count = 0;
        try {
            Date d1 = formatter.parse("2016-05-8 20:16:00");
            Date d2 = formatter.parse("2016-05-30 20:16:00");
            count = saturdaysundaycount(d1,d2);
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        System.out.println("Count of Sats & Sundays = "+count);
    }

    public static int saturdaysundaycount(Date d1, Date d2) {
        Calendar c1 = Calendar.getInstance();
        c1.setTime(d1);

        Calendar c2 = Calendar.getInstance();
        c2.setTime(d2);

        int sundays = 0;
        int saturday = 0;

        while (! c1.after(c2)) {
            if (c1.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY ){
                saturday++; 
            }
            if(c1.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY){
                sundays++;
            }

            c1.add(Calendar.DATE, 1);
        }

        System.out.println("Saturday Count = "+saturday);
        System.out.println("Sunday Count = "+sundays);
        return saturday + sundays;
    }

逻辑：你需要保持增量start date由一天忙到它超越end date并继续检查day上start date。