SonarSource/sonarqube · critical

Cannot detect path of main jar file

Error message

Cannot detect path of main jar file

What it means

AppSettingsLoaderImpl.detectHomeDir locates the SonarQube installation by resolving the code source of the org.sonar.application.App class and walking up two directory levels to find the home directory. If the class cannot be loaded or its location is not a valid URI, an IllegalStateException 'Cannot detect path of main jar file' is thrown during loader construction.

Solutions

  1. Start SonarQube with the official scripts (bin/run.sh / StartSonar.bat) so the application jar is on the classpath as distributed
  2. Verify sonar-application.jar exists in the lib directory and is not corrupted (reinstall/extract the distribution again)
  3. Avoid custom classloaders or shading that renames/moves org.sonar.application.App
  4. Move the installation to a plain path without unusual characters if URISyntaxException is the cause

Example fix

// before (custom launcher)
java -cp my-custom-boot.jar org.sonar.server.Server  // App class absent
// after
cd sonarqube-<version>/bin/linux-x86-64 && ./sonar.sh start
Defensive patterns

Strategy: try-catch

Validate before calling

try {
  Class.forName("org.sonar.application.App");
} catch (ClassNotFoundException e) {
  throw new IllegalStateException("sonar-application jar missing from classpath");
}

Try / catch

try {
  settingsLoader = new AppSettingsLoaderImpl(...);
} catch (IllegalStateException e) {
  if (e.getMessage().equals("Cannot detect path of main jar file")) {
    log.error("Launch SonarQube with the official start scripts; check sonar-application.jar in lib/", e.getCause());
  }
  throw e;
}

Prevention

When it happens

Trigger: Constructing AppSettingsLoaderImpl when org.sonar.application.App is missing from the classpath (ClassNotFoundException) or its code source location cannot be converted to a URI (URISyntaxException, e.g. paths with illegal characters or running from an unpacked/exotic classloader setup).

Common situations: Running the server with a repackaged or trimmed jar, launching via custom classloaders/frameworks instead of the official start scripts, jar paths with special characters (spaces are usually fine but URL-encoded quirks can break toURI), or partially extracted distributions.

Related errors

AI-assisted analysis of SonarSource/sonarqube@184c821202 (2026-09-09). Data as JSON: /api/errors/dae3784083628cb6. Report an issue: GitHub.

Appendix: source

Thrown at server/sonar-main/src/main/java/org/sonar/application/config/AppSettingsLoaderImpl.java:145

    // supports decryption of values, so it must be used when values
    // are accessed
    return new Props(p);
  }

  private static void loadPropertiesFromEnvironment(System2 system, Properties properties, Set<String> overridableSettings) {
    overridableSettings.forEach(key -> {
      String environmentVarName = fromJavaPropertyToEnvVariable(key);
      Optional<String> envVarValue = ofNullable(system.envVariable(environmentVarName));
      envVarValue.ifPresent(value -> properties.put(key, value));
    });
  }

  private static File detectHomeDir() {
    try {
      File appJar = new File(Class.forName("org.sonar.application.App").getProtectionDomain().getCodeSource().getLocation().toURI());
      return appJar.getParentFile().getParentFile();
    } catch (URISyntaxException | ClassNotFoundException e) {
      throw new IllegalStateException("Cannot detect path of main jar file", e);
    }
  }

  private static void warnOnNonSystemProperties(Properties fileProperties) {
    Set<String> systemKeys = stream(ProcessProperties.Property.values())
      .map(ProcessProperties.Property::getKey)
      .collect(Collectors.toSet());
    systemKeys.addAll(ADDITIONAL_SYSTEM_KEYS);

    fileProperties.stringPropertyNames().stream()
      .filter(key -> !systemKeys.contains(key))
      .filter(key -> !key.startsWith("sonar.log.level."))
      .filter(key -> MULTI_SERVER_LDAP_SETTINGS.stream().noneMatch(pattern -> key.matches(pattern.replace(".", "\\.").replace("*", "[^.]+"))))
      .sorted()
      .forEach(key -> LOG.warn(
        "Property '{}' is not a recognized system property. It cannot be managed from the UI or API when set here, and it may have no effect. Please check the documentation.",
        key));
  }

View on GitHub (pinned to 184c821202)