quarkusio/quarkus · error · IllegalArgumentException

Value: ' ' of property 'quarkus.spring-cloud-config.url' is…

Error message

Value: '${config.url()}' of property 'quarkus.spring-cloud-config.url' is invalid

What it means

DirectConfigServerBaseUrlProvider converts the quarkus.spring-cloud-config.url property into a java.net.URI for the Config Server base URL. When UrlUtility.toURI() raises a URISyntaxException the provider wraps it in an IllegalArgumentException naming the offending property value. The configured URL is syntactically invalid (bad characters, spaces, missing scheme, etc.).

Solutions

Correct the value of quarkus.spring-cloud-config.url to a valid absolute URI, e.g. http://config-server:8888
URL-encode any special characters or remove spaces/braces
Verify that property substitution resolved correctly (run with -Dquarkus.log.level=DEBUG or print effective config)

Example fix

// before
quarkus.spring-cloud-config.url=http://config server:8888

// after
quarkus.spring-cloud-config.url=http://config-server:8888

Defensive patterns

Strategy: validation

Validate before calling

String url = "http://config-server:8888";
try { new java.net.URI(url); } catch (URISyntaxException e) {
    throw new IllegalArgumentException("Invalid quarkus.spring-cloud-config.url: " + url, e);
}

Try / catch

catch (IllegalArgumentException e) { log.error("Fix quarkus.spring-cloud-config.url", e); }

Prevention

Always include scheme http:// or https://
Avoid spaces and unencoded special characters in the URL
Validate effective config in CI before deployment

When it happens

Trigger: Setting quarkus.spring-cloud-config.url to a malformed URI, e.g. 'http://config server:8888' (space), 'config-server:8888' (no scheme, parsed as unknown scheme), or containing unencoded special characters like '{' or '|'.

Common situations: Copy-pasting a URL with trailing whitespace or quotes from documentation; using environment-variable interpolation that leaves literal '${...}' text in the value; typos in the host/port.

Related errors

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/da7fddb220d000aa. Report an issue: GitHub.

Appendix: source

Thrown at extensions/spring-cloud-config-client/runtime/src/main/java/io/quarkus/spring/cloud/config/client/runtime/DirectConfigServerBaseUrlProvider.java:22

import java.net.URISyntaxException;

import io.quarkus.spring.cloud.config.client.runtime.util.UrlUtility;

public class DirectConfigServerBaseUrlProvider implements ConfigServerBaseUrlProvider {
    private final SpringCloudConfigClientConfig config;

    public DirectConfigServerBaseUrlProvider(SpringCloudConfigClientConfig config) {
        this.config = config;
    }

    @Override
    public URI get() {
        String url = config.url();
        validate(url);
        try {
            return UrlUtility.toURI(url);
        } catch (URISyntaxException e) {
            throw new IllegalArgumentException("Value: '" + config.url()
                    + "' of property 'quarkus.spring-cloud-config.url' is invalid", e);
        }
    }

    private void validate(String url) {
        if (null == url || url.isEmpty()) {
            throw new IllegalArgumentException(
                    "The 'quarkus.spring-cloud-config.url' property cannot be empty");
        }
    }
}

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