quarkusio/quarkus · error · IllegalArgumentException

Scheme was null

Error message

Scheme was null

What it means

UriBuilderImpl.schemeSpecificPart(String ssp) throws 'Scheme was null' when the ssp argument itself is null. The message is misleading: it mentions the scheme but actually guards the scheme-specific-part parameter. The JAX-RS contract mandates IllegalArgumentException for null arguments; the method cannot parse null into authority/path/query/fragment components.

Source

Thrown at independent-projects/resteasy-reactive/common/runtime/src/main/java/org/jboss/resteasy/reactive/common/jaxrs/UriBuilderImpl.java:310

        if (uri.getRawPath() != null && uri.getRawPath().length() > 0) {
            path = uri.getRawPath();
        }
        if (uri.getRawQuery() != null && uri.getRawQuery().length() > 0) {
            query = uri.getRawQuery();
        }

        return this;
    }

    public UriBuilder scheme(String scheme) throws IllegalArgumentException {
        this.scheme = scheme;
        return this;
    }

    public UriBuilder schemeSpecificPart(String ssp) throws IllegalArgumentException {
        if (ssp == null)
            throw new IllegalArgumentException("Scheme was null");

        StringBuilder sb = new StringBuilder();
        if (scheme != null)
            sb.append(scheme).append(':');
        if (ssp != null)
            sb.append(ssp);
        if (fragment != null && fragment.length() > 0)
            sb.append('#').append(fragment);
        URI uri = URI.create(sb.toString());

        if (uri.getRawSchemeSpecificPart() != null && uri.getRawPath() == null) {
            this.ssp = uri.getRawSchemeSpecificPart();
        } else {
            this.ssp = null;
            userInfo = uri.getRawUserInfo();
            host = uri.getHost();
            port = uri.getPort();
            path = uri.getRawPath();

View on GitHub (pinned to e1c734241f)

Solutions

1. Do not pass null: check the string before calling or skip the call when null
2. Fail fast with Objects.requireNonNull(ssp, 'ssp') at your call site
3. If optional, skip: if (ssp != null) builder.schemeSpecificPart(ssp);
4. Remember the message text is misleading - validate the ssp argument, not the builder scheme

Example fix

// before: builder.schemeSpecificPart(ssp); // throws if ssp null // after: if (ssp != null) { builder.schemeSpecificPart(ssp); }

if (ssp == null) {
    throw new IllegalArgumentException('scheme-specific part must not be null');
}

static boolean hasSsp(String ssp) {
    return ssp != null && !ssp.isEmpty();
}

try {
    builder.schemeSpecificPart(ssp);
} catch (IllegalArgumentException e) {
    throw new IllegalArgumentException('schemeSpecificPart argument was null (message text is misleading)', e);
}

When it happens

Trigger: Calling schemeSpecificPart(null) directly, or passing a String variable that was never initialized or that a lookup returned as null.

Common situations: Generated or reflective code calling schemeSpecificPart with an absent field; deserialized objects with null ssp; copy-paste of the uri(URI) null-check pattern where the guard was expected elsewhere.

Related errors

• URI is null
• path is null
• Illegal URI template${uriTemplate}
• invalid host
• invalid port

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/2a8bd252d4800aa4. Report an issue: GitHub.