根据年份和月份，获取某月多少天

/**
*根据年份和月份判断某月有多少天
* @param year
* @param month
* @return
*/
private int getDay(int year, int month) {
int day = 30;
boolean flag = false;
switch (year % 4) { //余0等于闰年
case 0:
flag = true;
break;
default:
flag = false;
break;
}
switch (month) {
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12:
day = 31;
break;
case 2:
day = flag ? 29 : 28; //闰年2月是29天
break;
default:
day = 30;
break;
}
return day;
}