Java如何计算两个时间段内的工作日天数

import java.text.ParseException;
import java.util.*;
import org.apache.commons.lang3.time.DateFORMatUtils;
import org.apache.commons.lang3.time.DateUtils;
public class CalcWorkDays {
    
    public static List<String> getHolidayList() {
        List<String> holidays = new ArrayList<>();
        // 元旦
        holidays.add("2021-01-01");
        holidays.add("2021-01-02");
        holidays.add("2021-01-03");
        // 春节
        holidays.add("2021-02-11");
        holidays.add("2021-02-12");
        holidays.add("2021-02-13");
        holidays.add("2021-02-14");
        holidays.add("2021-02-15");
        holidays.add("2021-02-16");
        holidays.add("2021-02-17");
        // 清明节
        holidays.add("2021-04-03");
        holidays.add("2021-04-04");
        holidays.add("2021-04-05");
        // 劳动节
        holidays.add("2021-05-01");
        holidays.add("2021-05-02");
        holidays.add("2021-05-03");
        holidays.add("2021-05-04");
        holidays.add("2021-05-05");
        // 端午节
        holidays.add("2021-06-12");
        holidays.add("2021-06-13");
        holidays.add("2021-06-14");
        // 中秋节
        holidays.add("2021-09-19");
        holidays.add("2021-09-20");
        holidays.add("2021-09-21");
        // 国庆节
        holidays.add("2021-10-01");
        holidays.add("2021-10-02");
        holidays.add("2021-10-03");
        holidays.add("2021-10-04");
        holidays.add("2021-10-05");
        holidays.add("2021-10-06");
        holidays.add("2021-10-07");
        return holidays;
    }
    
    public static List<String> getNeedWorkWeekends() {
        List<String> workWeekends = new ArrayList<>();
        workWeekends.add("2021-02-07");
        workWeekends.add("2021-02-20");
        workWeekends.add("2021-04-25");
        workWeekends.add("2021-05-08");
        workWeekends.add("2021-09-18");
        workWeekends.add("2021-09-26");
        workWeekends.add("2021-10-09");
        return workWeekends;
    }
    
    public static int calc(String start, String stop) throws ParseException {
    	//获取今年的法定节假日期
        List<String> workWeekends = getNeedWorkWeekends();
        //获取今年需要补班的日期
        List<String> holidays = getHolidayList();
      
        String pattern = "yyyy-MM-dd";
        Date begin = DateUtils.parseDate(start, pattern);
        Date endTime = DateUtils.parseDate(stop, pattern);
        Calendar cEnd = new GreGorianCalendar();
        cEnd.setTime(endTime);
        // 计算时算入stop当天
        cEnd.add(Calendar.DATE,1);
        Date end=cEnd.getTime();
        //
        Calendar c = Calendar.getInstance();
        c.setTime(begin);
        int count = 0;
        String ymd = null;
        while (c.getTime().before(end)) {
            ymd = DateFormatUtils.format(c.getTime(), pattern);
            // 不是法定节假日
            if (!holidays.contains(ymd)) {
                // 不是休息日
                if (workWeekends.contains(ymd)) {
                    count++;
                } else {
                    // 非周末
                    if (c.get(Calendar.DAY_OF_WEEK) != 1 && c.get(Calendar.DAY_OF_WEEK) != 7) {
                        count++;
                    }
                }
            }
            c.add(Calendar.DATE, 1);
        }
        return count;
    }
}

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
 

public class WeekEnd {	
	public static void main(String[] args) throws ParseException {
		  // 设置传入的时间格式  
	      SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
	      // 指定一个日期  
	      Date date1 = dateFormat.parse("2016-11-12 13:24:16");  
	      Date date2 = dateFormat.parse("2016-11-20 13:24:16");
	     //第三个三处代表是否 去除 双休日
	      System.out.println(computeHolidays(date2,date1));			
	}
	
	public static int computeHolidays(Date t1,Date t2) throws ParseException{
		//初始化第一个日期
		Calendar cal1 = Calendar.getInstance();
		//初始化第二个日期，这里的天数可以随便的设置
		Calendar cal2 = Calendar.getInstance(); 
 
		// 设置传入的时间格式  
		SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
		// 指定一个日期  
		Date date1 = dateFormat.parse(dateFormat.format(t1));  
		Date date2 = dateFormat.parse(dateFormat.format(t2));
		// 对 calendar 设置为 date 所定的日期  
		cal1.setTime(date1);  
		cal2.setTime(date2);
 
		int holidays = 0;
		//确定一个 大日期
		if(cal1.compareTo(cal2) > 0){
			Calendar temp = cal1;
			cal1 = cal2;
			cal2 = temp;
			temp = null;
		}
		while(cal1.compareTo(cal2)<=0){
			if(cal1.get(Calendar.DAY_OF_WEEK)==1||cal1.get(Calendar.DAY_OF_WEEK)==7){
				holidays++;
				System.out.println("周末："+new SimpleDateFormat("yyyy-MM-dd").format(cal1.getTime()));
			}
			cal1.add(Calendar.DAY_OF_YEAR,1);
			
		}
		return holidays;
	}	
}