package com.whn.hellospring.utils;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class DateUtils {

    /**
     * 计算两个日期之间相差的天数
     *
     * @param smdate 较小的时间
     * @param bdate  较大的时间
     * @return 相差天数
     */
    public static int daysBetween(Date smdate, Date bdate) {
        try {
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
            smdate = sdf.parse(sdf.format(smdate));
            bdate = sdf.parse(sdf.format(bdate));
            Calendar cal = Calendar.getInstance();
            cal.setTime(smdate);
            long time1 = cal.getTimeInMillis();
            cal.setTime(bdate);
            long time2 = cal.getTimeInMillis();
            long between_days = (time2 - time1) / (1000 * 3600 * 24);
            return Integer.parseInt(String.valueOf(between_days));
        } catch (Exception e) {
            return -1;
        }
    }
}