java代码：判断月份的最后一天是多少 原

//判断月份的最后一天是多少
String dateStr = "2016-07";
int year = Integer.parseInt(dateStr.substring(0, 4));
int month = Integer.parseInt(dateStr.substring(5, 7));
String end_data_mid = "31";
if(month == 2){
	if((year%4==0&&year%100!=0)||year%400==0) {
		end_data_mid = "29";
	}else{
		end_data_mid = "28";
	}
}else if(month == 4 || month == 6 || month == 9 || month == 11){
	end_data_mid = "30";
}