先将字符串转化为Date类型
然后在调用Date.getTime();方法得到毫秒数相减即可.
/**
* 计算两个日期间的天数
*
* @param fromDate
* 起始日期
* @param toDate
* 结束日期
* @return
* @throws ParseException
*/
public static int dateDiff(String fromDate, String toDate)
throws ParseException {
int days = 0;
SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd");
Date from = df.parse(fromDate);
Date to = df.parse(toDate);
days = (int) Math.abs((to.getTime() - from.getTime())
/ (24 * 60 * 60 * 1000)) + 1;
return days;
}