java 求两个日期之间工作日数

private int getWorkingDay(Calendar d1, Calendar d2) {
		int result = -1;   
		  if (d1.after(d2)) { // swap dates so that d1 is start and d2 is end   
		   java.util.Calendar swap = d1;   
		   d1 = d2;   
		   d2 = swap;   
		  }   
		  int betweendays = getDaysBetween(d1, d2);   
		  int charge_date = 0;   
		 int charge_start_date = 0;//开始日期的日期偏移量   
		  int charge_end_date = 0;//结束日期的日期偏移量   
		   // 日期不在同一个日期内   
		   int stmp;   
		   int etmp;   
		   stmp = 7 - d1.get(Calendar.DAY_OF_WEEK);   
		  etmp = 7 - d2.get(Calendar.DAY_OF_WEEK);   
		   if (stmp != 0 && stmp != 6) {// 开始日期为星期六和星期日时偏移量为0   
		    charge_start_date = stmp - 1;   
		   }   
		   if (etmp != 0 && etmp != 6) {// 结束日期为星期六和星期日时偏移量为0   
		    charge_end_date = etmp - 1;   
		   }   
 
		  result = (getDaysBetween(this.getNextMonday(d1), this.getNextMonday(d2)) / 7)   
		    * 5 + charge_start_date - charge_end_date;   
		 
		  System.out.println("between day is-->" + betweendays);   
		  return result;   
		
	}


	private Calendar getNextMonday(Calendar date) {
		Calendar result = null;   
		  result = date;   
		  do {   
		   result = (Calendar) result.clone();   
		   result.add(Calendar.DATE, 1);   
		  } while (result.get(Calendar.DAY_OF_WEEK) != 2);   
		  return result;   
	}


	private int getDaysBetween(Calendar d1, Calendar d2) {
		if (d1.after(d2)) { // swap dates so that d1 is start and d2 is end   
			   java.util.Calendar swap = d1;   
			   d1 = d2;   
			   d2 = swap;   
			  }   
			  int days = d2.get(java.util.Calendar.DAY_OF_YEAR)   
			    - d1.get(java.util.Calendar.DAY_OF_YEAR);   
			 int y2 = d2.get(java.util.Calendar.YEAR);   
			  if (d1.get(java.util.Calendar.YEAR) != y2) {   
			   d1 = (java.util.Calendar) d1.clone();   
			   do {   
			   days += d1.getActualMaximum(java.util.Calendar.DAY_OF_YEAR);   
			   d1.add(java.util.Calendar.YEAR, 1);   
			   } while (d1.get(java.util.Calendar.YEAR) != y2);   
			  }   
			  return days;   
	}