时间戳与指定格式时间的装换

/*
 * 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;
}

/*
 * 将时间戳转换为时间
 */
public static String stampToDate(String s){
    String res;
    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    long lt = new Long(s);
    Date date = new Date(lt);
    res = simpleDateFormat.format(date);
    return res;
}