common_helper/src/main/java/com/xiongyingqi/util/DateHelper.java
public static String getTwoDay(String sj1, String sj2) {
        SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");
        long day = 0;
        try {
            Date date = myFormatter.parse(sj1);
            Date mydate = myFormatter.parse(sj2);
            day = (date.getTime() - mydate.getTime()) / (24 * 60 * 60 * 1000);
        } catch (Exception e) {
            return "";
        }
        return day + "";
    }
public static String getTwoDay(String sj1, String sj2) {
        SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");
        long day = 0;
        try {
            Date date = myFormatter.parse(sj1);
            Date mydate = myFormatter.parse(sj2);
            day = (date.getTime() - mydate.getTime()) / (24 * 60 * 60 * 1000);
        } catch (Exception e) {
            return "";
        }
        return day + "";
    }
得到二个日期间的间隔天数