quarkusio/quarkus · error · IllegalArgumentException

Param cannot be null

Error message

Param cannot be null

What it means

RequestImpl.evaluatePreconditions(Date) throws IllegalArgumentException when the lastModified Date parameter is null, per the JAX-RS contract. It cannot evaluate If-Modified-Since/If-Unmodified-Since without a timestamp.

Source

Thrown at independent-projects/resteasy-reactive/server/runtime/src/main/java/org/jboss/resteasy/reactive/server/jaxrs/RequestImpl.java:155

            return null;
        }
        return Response.status(Response.Status.PRECONDITION_FAILED).lastModified(lastModified);

    }

    /**
     * We must compare header dates (seconds-precision) with dates that have the same precision,
     * otherwise they may include milliseconds and they will never match the Last-Modified
     * values that we generate from them (since we drop their milliseconds when we write the headers)
     */
    private long millisecondsWithSecondsPrecision(Date lastModified) {
        return (lastModified.getTime() / 1000) * 1000;
    }

    @Override
    public Response.ResponseBuilder evaluatePreconditions(Date lastModified) {
        if (lastModified == null)
            throw new IllegalArgumentException("Param cannot be null");
        Response.ResponseBuilder builder = null;
        MultivaluedMap<String, String> headers = requestContext.getHttpHeaders().getRequestHeaders();
        String ifModifiedSince = headers.getFirst(HttpHeaders.IF_MODIFIED_SINCE);
        if (ifModifiedSince != null && (!isRfc7232preconditions() || (!headers.containsKey(HttpHeaders.IF_NONE_MATCH)))) {
            builder = ifModifiedSince(ifModifiedSince, lastModified);
        }
        if (builder == null) {
            String ifUnmodifiedSince = headers.getFirst(HttpHeaders.IF_UNMODIFIED_SINCE);
            if (ifUnmodifiedSince != null && (!isRfc7232preconditions() || (!headers.containsKey(HttpHeaders.IF_MATCH)))) {
                builder = ifUnmodifiedSince(ifUnmodifiedSince, lastModified);
            }
        }
        if (builder != null && varyHeader != null)
            builder.header(HttpHeaders.VARY, varyHeader);

        return builder;
    }

View on GitHub (pinned to e1c734241f)

Solutions

1. Provide a valid lastModified Date, falling back to a creation timestamp or Instant.now().
2. When the timestamp is unknown, use the no-arg evaluatePreconditions() overload.
3. Null-check the date and return an unconditioned response builder when absent.

Example fix

// before
Response.ResponseBuilder rb = request.evaluatePreconditions(lastModified); // may be null
// after
Response.ResponseBuilder rb = lastModified != null
    ? request.evaluatePreconditions(lastModified)
    : request.evaluatePreconditions();

if (lastModified == null) {
    return request.evaluatePreconditions();
}

boolean hasTimestamp(Date d) {
    return d != null;
}

try {
    return request.evaluatePreconditions(lastModified);
} catch (IllegalArgumentException e) {
    return request.evaluatePreconditions();
}

When it happens

Trigger: Calling request.evaluatePreconditions(Date) with a null Date — e.g. the resource's modification timestamp was never set or the lookup returned null.

Common situations: File or entity metadata missing a last-modified value; a Date field that is null for newly created resources; passing an Optional-wrapped date after calling get() on an empty Optional.

Related errors

• Last modified was null
• ETag was null
• etag was null
• retrieving all roles not supported when JAX-RS security cont
• More than one Application class: ${applications}

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/d57b5ca1c9f85d56. Report an issue: GitHub.