quarkusio/quarkus · error · java.lang.IllegalArgumentException

Invalid REST Client URL used

Error message

Invalid REST Client URL used: '<uri>'

What it means

StorkClientRequestFilter.filter resolves the service name from the host of a stork:// URI and throws this IllegalArgumentException when the URI has the stork scheme but no host, i.e. it is malformed and no service name can be extracted.

Solutions

1. Set the URI to the full form stork://<service-name> with a non-empty host
2. Log/print requestContext.getUri() to see the parsed URI and fix the authority portion
3. Validate the configured URI at startup (assert URI.create(uri).getHost() != null for stork scheme)

Example fix

// before
quarkus.rest-client.my-client.uri=stork://
// after
quarkus.rest-client.my-client.uri=stork://my-service

URI uri = URI.create(clientUri);
if (uri.getScheme() != null && uri.getScheme().startsWith("stork")
        && uri.getHost() == null) {
    throw new IllegalArgumentException("stork URI must include a service name host, e.g. stork://my-service (got: " + clientUri + ")");
}

boolean isValidStorkUri(String uri) {
    URI u = URI.create(uri);
    return u.getScheme() != null && u.getScheme().startsWith("stork") && u.getHost() != null && !u.getHost().isBlank();
}

try {
    webTarget = client.target(clientUri);
    response = webTarget.request().get();
} catch (IllegalArgumentException e) {
    if (e.getMessage().startsWith("Invalid REST Client URL used")) {
        log.error("Fix the stork:// URI to include a service name");
    } else throw e;
}

When it happens

Trigger: Configuring a client URI like stork:// (empty host), stork:///service (empty host per URI parsing), a typo such as 'stork:/svc', or building a stork URI programmatically with URI.create where the authority was dropped.

Common situations: Property typos in quarkus.rest-client.<key>.uri; double slashes lost when templating; URI produced by string concatenation where the service name variable was empty.

Related errors

• Parameter type should be provided.
• Cannot read ' ' field from of class
• Delay must be > 0
• Delay must be > 0
• empty host

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/e7f01c2c83af363e. Report an issue: GitHub.

Appendix: source

Thrown at independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/StorkClientRequestFilter.java:48

            stork = Stork.getInstance();

            if (stork == null) {
                throw new IllegalStateException(
                        "Trying to use a StorkClientRequestFilter but the quarkus-smallrye-stork extension is missing, please add the extension.");
            }
        } catch (Exception e) {
            throw new IllegalStateException(
                    "Trying to use a StorkClientRequestFilter but the quarkus-smallrye-stork extension is missing, please add the extension.");
        }
    }

    @Override
    public void filter(ResteasyReactiveClientRequestContext requestContext) {
        URI uri = requestContext.getUri();
        if (uri != null && uri.getScheme() != null && uri.getScheme().startsWith(Stork.STORK)) {
            String serviceName = uri.getHost();
            if (serviceName == null) { // invalid URI
                throw new IllegalArgumentException("Invalid REST Client URL used: '" + uri + "'");
            }

            requestContext.suspend();
            boolean measureTime = shouldMeasureTime(requestContext.getResponseType());
            try {
                stork.getService(serviceName)
                        .selectInstanceAndRecordStart(measureTime)
                        .subscribe()
                        .with(instance -> {
                            boolean isHttps = instance.isSecure() || "storks".equals(uri.getScheme());
                            String scheme = isHttps ? "https" : "http";
                            try {
                                // In the case the service instance does not set the host and/or port
                                String host = instance.getHost() == null ? "localhost" : instance.getHost();
                                int port = instance.getPort();
                                if (instance.getPort() == 0) {
                                    if (isHttps) {
                                        port = 433;

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