不多说，直接上干货！

 

　　这是yyyy-MM-dd HH:mm:ss.S  

 

GetIntervalDays.java

 

 

package zhouls.bigdata.DataFeatureSelection.sim;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;public class GetIntervalDays {    public static void main(String[] args) throws ParseException {        String s1 = "2017-01-16 22:28:11.0";        String s2 = "2017-04-03 16:49:57.0";        Date d1 = parseDate(s1);//解析成Date类型        Date d2 = parseDate(s2);//解析成Date类型        System.out.println(d1);//Mon Jan 16 22:28:11 CST 2017        System.out.println(d2);//Mon Apr 03 16:49:57 CST 2017        System.out.println(getIntervalDays(d1,d2));//相差的天数76                            }    /**     * 把字符串解析成日期     * @param s     * @return d     * @throws ParseException     */    public static Date parseDate(String s) throws ParseException {        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.S");        Date d = sdf.parse(s);        return d;    }        /**     * 相差天数（隔24小时为相差1天，否则为0天）     * @param fDate     * @param oDate     * @return d     */    public static int getIntervalDays(Date fDate, Date oDate) {        if (null == fDate || null == oDate) {            return -1;        }        long intervalMilli = oDate.getTime() - fDate.getTime();        return (int) (intervalMilli / (24 * 60 * 60 * 1000));    }            }