根据年月得到月份第一天周几和一个月多少天

private int[] getMothMonDay1(String year,int month) {
int[] arr = new int[2];
Calendar cal = Calendar.getInstance();
   cal.set(Calendar.YEAR, Integer.parseInt(year));
   cal.set(Calendar.MONTH, month-1);
cal.set(Calendar.DAY_OF_MONTH, 1);
int lastDay = cal.getActualMaximum(Calendar.DAY_OF_MONTH);

int i = 1;
while(cal.get(Calendar.DAY_OF_WEEK) != Calendar.MONDAY){
cal.set(Calendar.DAY_OF_MONTH, i++);
}
   int j = cal.get(Calendar.DATE);
   arr[0] = j;
   arr[1] = lastDay;
   return arr;
}