Java 在爪哇如何在两次约会之间获得周六和周日

在这个函数中，我试图获得两个日期之间的星期六和星期日的总数。但当我超过了日期，结果是零。请指出错误并提出改正建议

问题在于您的

，而
，这段代码对我来说运行良好

检查
endDate
和
startDate
，因为我猜您发送的顺序不对

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;
            }

不建议编写完整的程序，但由于您付出了努力，下面是在我的系统上运行并返回值
7

public static int getNumberofSundays(String d1,String d2) throws Exception{ //object in Date form
    Date date1=getDate(d1);
    Date date2=getDate(d2);

    Calendar c1=Calendar.getInstance();
    c1.setTime(date1);
    Calendar c2=Calendar.getInstance();
    c2.setTime(date2);
    int sundays=0;
    while(c1.after(c2)){
        if(c2.get(Calendar.DAY_OF_WEEK)==Calendar.SUNDAY){
            sundays++;
            c2.add(Calendar.DATE,1);
        }
    }
    System.out.println("number of days between 2 dates"+sundays);

    return sundays;
}

逻辑：您需要将增量
开始日期
保留一天，直到它结束
超过
结束日期
并在
开始日期
上继续检查
日期

您的代码不会在几天内循环。请尝试以下代码。在while循环中，它循环给定的第一个日期和最后一个日期之间的所有日期。它通过在每次迭代中向c1添加一天来实现这一点，直到c1在c2之后。这将给出给定日期之间（包括这两天）的星期六和星期日数

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;
    }

类似的问题也得到了回答。更改逻辑说明我尝试过亲爱的我无法做到这一点它总是返回0if（startCal.get（Calendar.DAY\u OF u WEEK）==Calendar.SATURDAY&&startCal.get（Calendar.DAY\u OF u WEEK）==Calendar.SUNDAY）我已经应用了这个逻辑为什么你要这样做
c2.add（Calendar.DATE，1）两次？c2.add（Calendar.DATE，2）；错误来了，我们必须加上星期六，不仅是星期天，同样的方法是计算星期六，看这是它，但它不是working@ResearchDevelopment“找不到404”
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;
    }

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 saturdays = 0;

    while (!c1.after(c2)) {
        SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd-E");
        String formatted = format1.format(c1.getTime());
        System.out.println("Current Date C1 : " + formatted);

        if (c1.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY) {
            sundays++;
        } else if (c1.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY) {
            saturdays++;
        }
        c1.add(Calendar.DATE, 1);
    }

    System.out.println("Sundays : " + sundays);
    System.out.println("Saturdays : " + saturdays);

    return saturdays + sundays;
}