java - 在 main() 中调用 int 函数来显示当前工作日

Question

我对java很陌生，发现下面的代码可以获取不包括周六和周日的工作日数。

我需要知道如何在 main() 中调用此函数来显示当月的workDays。

谢谢。

package mypkg;

import java.sql.Date;
import java.util.Calendar;

public class workrays {

    public static int getWorkingDaysBetweenTwoDates(Date startDate, Date endDate) {
        Calendar startCal;
        Calendar endCal;
        startCal = Calendar.getInstance();
        startCal.setTime(startDate);
        endCal = Calendar.getInstance();
        endCal.setTime(endDate);
        int workDays = 0;

        //Return 0 if start and end are the same
        if (startCal.getTimeInMillis() == endCal.getTimeInMillis()) {
            return 0;
        }

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

        do {
            startCal.add(Calendar.DAY_OF_MONTH, 1);
            if (startCal.get(Calendar.DAY_OF_WEEK) != Calendar.SATURDAY
            && startCal.get(Calendar.DAY_OF_WEEK) != Calendar.SUNDAY) {
                ++workDays;
            }
        } while (startCal.getTimeInMillis() < endCal.getTimeInMillis());

        return workDays;
    }

    public static void main(String args[]) {

        getWorkingDaysBetweenTwoDates(Date startDate, Date endDate);
        System.out.println(workdays);       
    }
}

Answer 1

首先，您应该使用java.util.Date，而不是java.sql.Date。其次，您需要先创建 Date 实例，然后再将其发送到 getWorkingDaysBetweenTwoDates 函数。第三，您需要将 getWorkingDaysBetweenTwoDates 函数的结果存储在局部变量中，然后使用它。为了创建 Date，您可以使用 SimpleDateFormat 对象:

public static void main(String[] args) {
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
    try {
        Date startDate = sdf.parse("2013-02-20");
        Date endDate = sdf.parse("2013-02-22");
        int workdays = getWorkingDaysBetweenTwoDates(startDate, endDate);
        System.out.println(workdays);
    } catch (Exception e) {
        System.out.println("There's an error somewhere. Check the stacktrace to find it");
        e.printStackTrace(System.out);
    }
}

<小时/>

根据您的评论，您可以创建另一个函数，通过发送 Date 来返回包含第一个日期值的 Date 实例:

public static Date getFirstDateOfMonth(Date aDate) {
    Calendar c = Calendar.getInstance();
    c.setTime(aDate);
    c.set(Calendar.DATE, 1);
    return c.getTime();
}

你可以这样调用它:

public static void main(String[] args) {
   Date endDate = new Date(); //current date/time
   Date startDate = getFirstDateOfMonth(endDate);
   int workdays = getWorkingDaysBetweenTwoDates(startDate, endDate);
   System.out.println(workdays);
}