获取时间帮助类

public class GetTime {
    /**
     * 获取当前时间
     *
     * @param type
     * @return
     */
    public static String getDateToString(String type, long time) {
        SimpleDateFormat sf = new SimpleDateFormat(type);
        Date d = new Date(time);
        return sf.format(d);
    }

    /**
     * 获取指定哪天的日期
     * 如  day=2   就是后天
     * day=-2  就是前天
     *
     * @param day 正数向后推，负数向前推
     * @return
     */
    public static String getLastDateToString(int day) {
        Calendar cal = Calendar.getInstance();
        cal.add(Calendar.DATE, day);
        return new SimpleDateFormat("yyyy-MM-dd").format(cal.getTime());
    }

    public static String getLastDateTimeToString(int day) {
        Calendar cal = Calendar.getInstance();
        cal.add(Calendar.DATE, day);
        return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(cal.getTime());
    }

    /**
     * 获取当前星期
     *
     * @param date
     * @return
     */
    public static String getWeekday(String date) {//必须yyyy-MM-dd
        SimpleDateFormat sd = new SimpleDateFormat("yyyy-MM-dd");
        SimpleDateFormat sdw = new SimpleDateFormat("E");
        Date d = null;
        try {
            d = sd.parse(date);
        } catch (ParseException e) {
            e.printStackTrace();

        }
        return sdw.format(d);

    }

    /*
     * 将时间转换为时间戳
     */
    public static String dateToStamp(String s) throws ParseException {
        String res;
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Date date = simpleDateFormat.parse(s);
        long ts = date.getTime();
        res = String.valueOf(ts);
        return res;
    }

    /**
     * 获取当前日的开始时间戳
     * 即  xxxx-xx-xx 00:00:00
     *
     * @return
     * @throws ParseException
     */
    public static String dayStartTime() throws ParseException {
        Calendar startCal = new GregorianCalendar();
        startCal.set(Calendar.HOUR_OF_DAY, 0);
        startCal.set(Calendar.MINUTE, 0);
        startCal.set(Calendar.SECOND, 0);
        return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(startCal.getTime());
    }

    /**
     * 获取当前日的结束时间戳
     * 即  xxxx-xx-xx 23:59:59
     *
     * @return
     * @throws ParseException
     */
    public static String dayEndTime() throws ParseException {
        Calendar endCal = new GregorianCalendar();
        endCal.set(Calendar.HOUR_OF_DAY, 23);
        endCal.set(Calendar.MINUTE, 59);
        endCal.set(Calendar.SECOND, 59);

        return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(endCal.getTime());
    }


}