brettwooldridge/HikariCP · critical · RuntimeException

Driver {} claims to not accept jdbcUrl, {}

Error message

Driver {} claims to not accept jdbcUrl, {}

What it means

DriverDataSource constructor verifies that a driver explicitly configured via dataSourceClassName/driverClassName actually accepts the jdbcUrl (driver.acceptsURL). If it returns false, HikariCP throws RuntimeException naming the driver class and (password-masked) URL — the driver and URL do not match.

Source

Thrown at src/main/java/com/zaxxer/hikari/util/DriverDataSource.java:116

            if (driverClass != null) {
               try {
                  driver = (Driver) driverClass.getDeclaredConstructor().newInstance();
               } catch (Exception e) {
                  LOGGER.warn("Failed to create instance of driver class {}, trying jdbcUrl resolution", driverClassName, e);
               }
            }
         }
      }

      final var sanitizedUrl = maskPasswordInJdbcUrl(jdbcUrl);

      try {
         if (driver == null) {
            driver = DriverManager.getDriver(jdbcUrl);
            LOGGER.debug("Loaded driver with class name {} for jdbcUrl={}", driver.getClass().getName(), sanitizedUrl);
         }
         else if (!driver.acceptsURL(jdbcUrl)) {
            throw new RuntimeException("Driver " + driverClassName + " claims to not accept jdbcUrl, " + sanitizedUrl);
         }
      }
      catch (SQLException e) {
         throw new RuntimeException("Failed to get driver instance for jdbcUrl=" + sanitizedUrl, e);
      }
   }

   @Override
   public Connection getConnection() throws SQLException
   {
      return driver.connect(jdbcUrl, driverProperties);
   }

   @Override
   public Connection getConnection(final String username, final String password) throws SQLException
   {
      final var cloned = (Properties) driverProperties.clone();
      if (username != null) {

View on GitHub (pinned to a4d93f4f85)

Solutions

1. Align driverClassName with the jdbcUrl family (e.g. org.mariadb.jdbc.Driver with jdbc:mariadb://)
2. Drop driverClassName entirely and let DriverManager auto-detect from the URL (HikariCP resolves it via jdbcUrl)
3. Fix typos in the jdbc:subprotocol and verify the URL against the driver docs
4. Upgrade the driver if its acceptsURL is known to be buggy for your URL form

Example fix

# before
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mariadb://db:3306/app

# after
driver-class-name=org.mariadb.jdbc.Driver
url=jdbc:mariadb://db:3306/app

// sanity-check before pool creation
Driver d = DriverManager.getDriver(jdbcUrl);
if (explicitDriver != null && !explicitDriver.acceptsURL(jdbcUrl)) {
    throw new IllegalStateException("driver/url mismatch");
}

When it happens

Trigger: Setting jdbcUrl to one database family (e.g. jdbc:mysql://) while driverClassName points at another driver (e.g. org.postgresql.Driver); a driver whose acceptsURL is strict about URL syntax/extra properties; wrong/typo'd jdbc: subprotocol.

Common situations: Copy-pasted configs across environments, MySQL vs MariaDB driver mixups (jdbc:mariadb:// with com.mysql.cj.jdbc.Driver), custom sharding proxies whose acceptsURL differs by version.

Related errors

• Failed to get driver instance for jdbcUrl={}
• Failed to load class ${className}
• Invalid transaction isolation value: ${transactionIsolationN
• connectionTimeout cannot be less than ${SOFT_TIMEOUT_FLOOR}m
• idleTimeout cannot be negative

AI-assisted analysis of brettwooldridge/HikariCP@a4d93f4f85 (2026-08-14). Data as JSON: /api/errors/dd5cca7a1606076b. Report an issue: GitHub.