code: public String toTimeStr() {
  		if (null != this.timeZone) {
  			final SimpleDateFormat simpleDateFormat = new SimpleDateFormat(DatePattern.NORM_TIME_PATTERN);
  			simpleDateFormat.setTimeZone(this.timeZone);
  			return toString(simpleDateFormat);
  		}
  		return toString(DatePattern.NORM_TIME_FORMAT);
  	}
docs: 转为"HH:mm:ss" 格式字符串
  
  @return "HH:mm:ss" 格式字符串
  @since 4.1.4