SonarSource/sonarqube · error · IllegalStateException

The property ' ' is not a float value

Error message

The property '%s' is not a float value

What it means

Settings.getFloat retrieves the string value of a property and converts it to a Float. If the value is non-empty but not a valid float, the NumberFormatException is replaced by this IllegalStateException. The library throws it because numeric settings must be parseable and an unparseable value is a configuration error.

Solutions

1. Correct the stored value to a valid float using '.' as the decimal separator (e.g. 12.5)
2. Validate the value before calling getFloat (parse with Float.valueOf yourself or use a regex)
3. Re-save the property via UI/API with a proper numeric value
4. Fall back to getDefaultValue or a sane default if the property may be user-supplied

Example fix

// before
Float f = settings.getFloat("sonar.threshold"); // value = "12,5"
// after
settings.setProperty("sonar.threshold", "12.5");
Float f = settings.getFloat("sonar.threshold");

// validate before calling getFloat
String v = settings.getString(key);
if (v != null && !v.trim().isEmpty()) {
  try { Float.valueOf(v.trim()); }
  catch (NumberFormatException e) {
    throw new IllegalArgumentException("property " + key + " must be a float, got: " + v);
  }
}

try {
  return settings.getFloat(key);
} catch (IllegalStateException e) {
  log.warn("Non-float value for {} - using default", key, e);
  return defaultValue;
}

When it happens

Trigger: Calling getFloat(key) when the property holds text like '12.5x', a localized decimal separator (e.g. comma), an empty-but-present value, or any non-numeric string.

Common situations: Users typing values with commas as decimal separators in sonar.properties or the UI; typos in numeric thresholds; values set programmatically from unvalidated input.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• The property ' ' is not a double value
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AI-assisted analysis of SonarSource/sonarqube@184c821202 (2026-09-09). Data as JSON: /api/errors/5c0bc9e47dfd51d3. Report an issue: GitHub.

Appendix: source

Thrown at sonar-plugin-api-impl/src/main/java/org/sonar/api/config/internal/Settings.java:244

    }
    return null;
  }

  /**
   * Effective value as {@code Float}.
   *
   * @return the value as {@code Float}. If the property does not have value nor default value, then {@code null} is returned.
   * @throws NumberFormatException if value is not empty and is not a parsable number
   */
  @CheckForNull
  @Override
  public Float getFloat(String key) {
    String value = getString(key);
    if (StringUtils.isNotEmpty(value)) {
      try {
        return Float.valueOf(value);
      } catch (NumberFormatException e) {
        throw new IllegalStateException(String.format("The property '%s' is not a float value", key));
      }
    }
    return null;
  }

  /**
   * Effective value as {@code Double}.
   *
   * @return the value as {@code Double}. If the property does not have value nor default value, then {@code null} is returned.
   * @throws NumberFormatException if value is not empty and is not a parsable number
   */
  @CheckForNull
  @Override
  public Double getDouble(String key) {
    String value = getString(key);
    if (StringUtils.isNotEmpty(value)) {
      try {
        return Double.valueOf(value);

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