SonarSource/sonarqube · error · IllegalArgumentException

Value '%s' is not a number

Error message

Value '%s' is not a number

What it means

Metric criteria in the project measures search must carry a numeric value. parseValue, called from createMetricCriterion, uses Double.parseDouble and rethrows NumberFormatException as this IllegalArgumentException when the criterion value is not parseable as a number.

Source

Thrown at server/sonar-webserver-webapi/src/main/java/org/sonar/server/component/ws/ProjectMeasuresQueryFactory.java:167

  private static void processMetricCriterion(Criterion criterion, ProjectMeasuresQuery query) {
    checkOperator(criterion);
    checkValue(criterion);
    query.addMetricCriterion(createMetricCriterion(criterion, criterion.getKey().toLowerCase(ENGLISH), criterion.getOperator()));
  }

  private static MetricCriterion createMetricCriterion(Criterion criterion, String metricKey, Operator operator) {
    if (NO_DATA.equalsIgnoreCase(criterion.getValue())) {
      checkArgument(EQ.equals(operator), "%s can only be used with equals operator", NO_DATA);
      return MetricCriterion.createNoData(metricKey);
    }
    return MetricCriterion.create(metricKey, operator, parseValue(criterion.getValue()));
  }

  private static double parseValue(String value) {
    try {
      return Double.parseDouble(value);
    } catch (NumberFormatException e) {
      throw new IllegalArgumentException(format("Value '%s' is not a number", value));
    }
  }

  private static void checkValue(Criterion criterion) {
    checkArgument(criterion.getValue() != null, "Value cannot be null for '%s'", criterion.getKey());
  }

  private static void checkOperator(Criterion criterion) {
    checkArgument(criterion.getOperator() != null, "Operator cannot be null for '%s'", criterion.getKey());
  }
}

View on GitHub (pinned to 184c821202)

Solutions

  1. Ensure the metric value is a plain number using '.' as decimal separator (e.g. 'coverage >= 80').
  2. Strip units, currency symbols, thousands separators and whitespace from the value.
  3. Check that the criterion did not get split so the operator/value landed in the wrong field.
  4. Handle percentages as 0-100 numbers (e.g. coverage >= 80, not 0.8).

Example fix

// before
String criteria = "ncloc > 1,000"; // comma not parseable
// after
String criteria = "ncloc > 1000";
Defensive patterns

Strategy: validation

Validate before calling

if (!value.matches("-?\\d+(\\.\\d+)?")) {
  throw new IllegalArgumentException("Metric value must be a plain number with '.' decimal separator: " + value);
}

Try / catch

try {
  response = ws.searchProjects("coverage >= " + value);
} catch (IllegalArgumentException e) {
  if (e.getMessage().contains("is not a number")) {
    double normalized = Double.parseDouble(value.replace(',', '.'));
    response = ws.searchProjects("coverage >= " + normalized);
  } else throw e;
}

Prevention

When it happens

Trigger: Sending a metric criterion with a non-numeric or empty value, e.g. 'coverage >= abc', 'ncloc > "1,000"' (comma thousand separator), 'coverage >= ' (empty), or locale-formatted numbers like '95,5'.

Common situations: Copy-pasting displayed measure values (with units or separators) into filters; localization producing comma decimal separators; forgetting to quote/escape values so the parser splits incorrectly.

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

AI-assisted analysis of SonarSource/sonarqube@184c821202 (2026-09-09). Data as JSON: /api/errors/783eb28eb902d395. Report an issue: GitHub.