时间戳转换成日期格式字符串

/**
 * 时间戳转换成日期格式字符串
 * @param seconds 精确到秒的字符串
 * @param formatStr
 */
public static String timeStamp2Date(String seconds, String format) {
    if (seconds == null || seconds.isEmpty() || seconds.equals("null")) {
        return "";
    }
    if (format == null || format.isEmpty()) {
        format = "yyyy-MM-dd HH:mm:ss";
    }
    SimpleDateFormat sdf = new SimpleDateFormat(format);
    return sdf.format(new Date(Long.valueOf(seconds + "000")));
}