public static void main(String[] args) throws ParseException {
String dateStr = "2016-05-18";
//1、获取string对应date日期:
Date date = new SimpleDateFormat("yyyy-MM-dd").parse(dateStr );
//2、获取date对应的Calendar对象
Calendar ca = Calendar.getInstance();
ca.setTime(date);
//3、可以从ca中获取各种该日期的属性值:
int day = ca.get(Calendar.DAY_OF_YEAR);//一年中的第几天
int week = ca.get(Calendar.WEEK_OF_YEAR);//一年中的第几周
int month = ca.get(Calendar.MONTH);//第几个月
int year = ca.get(Calendar.YEAR);//年份数值
System.out.println("year==="+year);
System.out.println("month==="+month);
}