t8y2/dbx · error · IllegalArgumentException

No JDBC driver was discovered. Enter the driver class name f

Error message

No JDBC driver was discovered. Enter the driver class name for this JAR.

What it means

Thrown by registerDrivers in DbxJdbcPlugin after scanning a supplied JAR for JDBC driver classes: no class implementing java.sql.Driver was found or loadable, so the plugin cannot register anything. The plugin parses JARs, inspects META-INF/services/java.sql.Driver and candidate classes, and wraps them in a shim; if `loaded` stays false while JAR URLs exist, it fails fast with this IllegalArgumentException instead of failing later at connect time.

Source

Thrown at plugins/jdbc/src/main/java/app/dbx/jdbc/DbxJdbcPlugin.java:620

            Driver driver = (Driver) constructor.newInstance();
            registeredDriver = new DriverShim(driver);
            DriverManager.registerDriver(registeredDriver);
            registeredDriverKey = driverKey;
            return;
        }

        boolean loaded = false;
        Driver first = null;
        for (Driver driver : ServiceLoader.load(Driver.class, loader)) {
            Driver shim = new DriverShim(driver);
            if (first == null) {
                first = shim;
            }
            DriverManager.registerDriver(shim);
            loaded = true;
        }
        if (!loaded && !urls.isEmpty()) {
            throw new IllegalArgumentException("No JDBC driver was discovered. Enter the driver class name for this JAR.");
        }
        registeredDriver = first;
        registeredDriverKey = driverKey;
    }

    private static Connection openConnection(JsonNode connection) throws SQLException {
        String url = jdbcUrl(connection);
        if (url == null) {
            throw new IllegalArgumentException("JDBC URL is required.");
        }
        String key = connectionKey(connection);
        if (sharedConnection != null && key.equals(sharedConnectionKey) && !isConnectionClosed(sharedConnection)) {
            configureOrdinaryAutoCommit(sharedConnection);
            return sharedConnection;
        }
        closeSharedConnection();

        JdbcUrlCredentials urlCredentials = extractJdbcUrlCredentials(url);

View on GitHub (pinned to c0390bff16)

Solutions

1. Verify the JAR is the actual JDBC driver artifact (e.g. postgresql-42.x.jar, ojdbc11.jar) and the file path/URL is correct and readable.
2. Open the JAR and check META-INF/services/java.sql.Driver exists listing the driver class; if missing, add the services entry or use the vendor's official driver JAR.
3. Since the message says to enter the driver class name, supply the fully-qualified driver class explicitly (e.g. org.postgresql.Driver) via the plugin's driver-class option.
4. Run on a JDK version compatible with the driver's class-file version and ensure all of the driver's dependency JARs are on the classpath.

Example fix

// before
jarPath = "/libs/hikariCP.jar";            // connection pool, not a driver
registerDrivers(List.of(jarPath), null);
// after
jarPath = "/libs/postgresql-42.7.3.jar";    // actual driver jar
registerDrivers(List.of(jarPath), "org.postgresql.Driver"); // explicit class

// Java: verify jar is a driver jar before registering
boolean isDriverJar(Path jar) throws IOException {
    try (var zf = new java.util.zip.ZipFile(jar.toFile())) {
        return zf.getEntry("META-INF/services/java.sql.Driver") != null;
    }
}
if (!isDriverJar(Path.of(jarPath))) throw new IllegalStateException(jarPath + " has no java.sql.Driver service entry");

When it happens

Trigger: Calling the plugin's driver-registration flow (via handleLine) with a JAR path that contains no JDBC Driver implementation, a shaded/obfuscated driver whose services file was stripped, or a JAR whose driver class fails to load/instantiate (missing dependencies, wrong Java bytecode version).

Common situations: Pointing at the wrong JAR (e.g. a driver's non-driver companion jar), fat-jar repackaging that dropped META-INF/services entries, a driver compiled for a newer JDK than the runtime, or a JAR URL typo (file not found produces no discoverable driver).

Related errors

• JDBC pool registry must be attached before connecting
• Not connected
• JDBC Session was quarantined while waiting for a connection
• Object source is not supported
• Completion assistant search is not supported by this agent

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/ce03a59bfa18cd37. Report an issue: GitHub.