quarkusio/quarkus · error · IllegalArgumentException

Different array length

Error message

Different array length

What it means

IllegalArgumentException from PausableHttpPostRequestEncoder.addBodyFileUploads: the parallel arrays passed for a multi-file upload parameter (files, contentTypes, isText) have different lengths. Each file needs exactly one content type and one isText flag; the array length mismatch is the fault.

Source

Thrown at independent-projects/resteasy-reactive/client/runtime/src/main/java/org/jboss/resteasy/reactive/client/impl/multipart/PausableHttpPostRequestEncoder.java:493

     * Add a series of Files associated with one File parameter
     *
     * @param name
     *        the name of the parameter
     * @param file
     *        the array of files
     * @param contentType
     *        the array of content Types associated with each file
     * @param isText
     *        the array of isText attribute (False meaning binary mode) for each file
     * @throws IllegalArgumentException
     *         also throws if array have different sizes
     * @throws ErrorDataEncoderException
     *         if the encoding is in error or if the finalize were already done
     */
    public void addBodyFileUploads(String name, File[] file, String[] contentType, boolean[] isText)
            throws ErrorDataEncoderException {
        if (file.length != contentType.length && file.length != isText.length) {
            throw new IllegalArgumentException("Different array length");
        }
        for (int i = 0; i < file.length; i++) {
            addBodyFileUpload(name, file[i], contentType[i], isText[i]);
        }
    }

    /**
     * Add the InterfaceHttpData to the Body list
     *
     * @throws NullPointerException
     *         for data
     * @throws ErrorDataEncoderException
     *         if the encoding is in error or if the finalize were already done
     */
    public void addBodyHttpData(InterfaceHttpData data) throws ErrorDataEncoderException {
        if (headerFinalized) {
            throw new ErrorDataEncoderException("Cannot add value once finalized");
        }

View on GitHub (pinned to e1c734241f)

Solutions

1. Pad missing content types with a sensible default (e.g. application/octet-stream) before the call
2. Assert array lengths are equal before calling addBodyFileUploads
3. Switch to calling addBodyFileUpload per file to avoid parallel-array pitfalls

Example fix

// before
encoder.addBodyFileUploads("files", files, contentTypes, isTextFlags);
// after
if (files.length != contentTypes.length || files.length != isTextFlags.length) {
    throw new IllegalStateException("arrays must match");
}
encoder.addBodyFileUploads("files", files, contentTypes, isTextFlags);

if (file.length != contentType.length || file.length != isText.length) { throw new IllegalArgumentException("arrays must have equal length"); }

null

try { encoder.addBodyFileUploads(name, files, types, flags); } catch (IllegalArgumentException e) { /* fix arrays or add one-by-one */ }

When it happens

Trigger: Calling addBodyFileUploads with arrays of mismatched lengths, e.g. file.length=2 but contentType.length=1.

Common situations: Building parallel arrays programmatically and skipping an entry for a file with unknown content type; refactoring single-upload code to batch mode.

Related errors

• setting content of MultiByteHttpData is not supported
• adding content to MultiByteHttpData is not supported
• getting all the contents of a MultiByteHttpData is not suppo
• MultiByteHttpData invoked on an invalid context :
• Reading MultiByteHttpData as String is not supported

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/b61dfe11adf4f6b5. Report an issue: GitHub.