MyCATApache/Mycat-Server · error · IllegalArgumentException

Interval string does not match second-nano format of…

Error message

Interval string does not match second-nano format of ss.nnnnnnnnn

What it means

parseSecondNano parses a seconds-with-fraction string like '12.999999999' and throws this IllegalArgumentException when the input does not split into exactly two parts around the decimal point with non-empty valid components — i.e. it is not in ss.nnnnnnnnn form.

Solutions

1. Ensure the string has exactly one '.' separating integer seconds and nanoseconds, e.g. '12.5' not '12' or '12.5.6'
2. Convert locale decimal commas to '.' before parsing
3. Validate with a regex like ^\d*\.\d*$ before calling

Example fix

// before
long micros = interval.parseSecondNano("12,5");
// after
long micros = interval.parseSecondNano("12.500000000");

private static final Pattern SS_N = Pattern.compile("^\\d*\\.\\d{1,9}$");
static void requireSecondNano(String s) {
  if (s == null || !SS_N.matcher(s).matches())
    throw new IllegalArgumentException("expected ss.nnnnnnnnn, got: " + s);
}

static boolean isSecondNano(String s) {
  return s != null && s.matches("\\d*\\.\\d{1,9}");
}

try {
  long micros = parseSecondNano(s);
} catch (IllegalArgumentException e) {
  log.warn("Malformed seconds.nanos '{}'", s);
  micros = 0L;
}

When it happens

Trigger: Calling CalendarInterval.parseSecondNano("12"), parseSecondNano("1.2.3"), parseSecondNano("abc.def"), or parseSecondNano("") — e.g. from the micros() accessor with a malformed seconds string.

Common situations: Truncated fractional seconds from string splitting, locale decimal commas ('12,5'), missing nano part after the dot.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

• Interval string does not match year-month format of 'y-m':
• Interval string does not match day-time format of 'd…
• outside range [ , ]
• Interval year-month string was null
• Error parsing interval year-month string:

AI-assisted analysis of MyCATApache/Mycat-Server@65f8d8beb7 (2026-09-11). Data as JSON: /api/errors/4abb246875acc232. Report an issue: GitHub.

Appendix: source

Thrown at src/main/java/io/mycat/memory/unsafe/types/CalendarInterval.java:247

  }

  /**
   * Parse second_nano string in ss.nnnnnnnnn format to microseconds
   */
  public static long parseSecondNano(String secondNano) throws IllegalArgumentException {
    String[] parts = secondNano.split("\\.");
    if (parts.length == 1) {
      return toLongWithRange("second", parts[0], Long.MIN_VALUE / MICROS_PER_SECOND,
        Long.MAX_VALUE / MICROS_PER_SECOND) * MICROS_PER_SECOND;

    } else if (parts.length == 2) {
      long seconds = parts[0].equals("") ? 0L : toLongWithRange("second", parts[0],
        Long.MIN_VALUE / MICROS_PER_SECOND, Long.MAX_VALUE / MICROS_PER_SECOND);
      long nanos = toLongWithRange("nanosecond", parts[1], 0L, 999999999L);
      return seconds * MICROS_PER_SECOND + nanos / 1000L;

    } else {
      throw new IllegalArgumentException(
        "Interval string does not match second-nano format of ss.nnnnnnnnn");
    }
  }

  public final int months;
  public final long microseconds;

  public CalendarInterval(int months, long microseconds) {
    this.months = months;
    this.microseconds = microseconds;
  }

  public CalendarInterval add(CalendarInterval that) {
    int months = this.months + that.months;
    long microseconds = this.microseconds + that.microseconds;
    return new CalendarInterval(months, microseconds);
  }

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