protected void init()

in commons-fileupload2-core/src/main/java/org/apache/commons/fileupload2/core/FileItemInputIteratorImpl.java [229:277]
42 lines of code
9 McCabe index (conditional complexity)

    protected void init(final AbstractFileUpload<?, ?, ?> fileUploadBase, final RequestContext initContext) throws FileUploadException, IOException {
        final var contentType = requestContext.getContentType();
        if (null == contentType || !contentType.toLowerCase(Locale.ENGLISH).startsWith(AbstractFileUpload.MULTIPART)) {
            throw new FileUploadContentTypeException(String.format("the request doesn't contain a %s or %s stream, content type header is %s",
                    AbstractFileUpload.MULTIPART_FORM_DATA, AbstractFileUpload.MULTIPART_MIXED, contentType), contentType);
        }
        final var contentLengthInt = requestContext.getContentLength();
        // @formatter:off
        final var requestSize = RequestContext.class.isAssignableFrom(requestContext.getClass())
                                 // Inline conditional is OK here CHECKSTYLE:OFF
                                 ? requestContext.getContentLength()
                                 : contentLengthInt;
                                 // CHECKSTYLE:ON
        // @formatter:on
        final InputStream inputStream; // N.B. this is eventually closed in MultipartInput processing
        if (sizeMax >= 0) {
            if (requestSize != -1 && requestSize > sizeMax) {
                throw new FileUploadSizeException(
                        String.format("the request was rejected because its size (%s) exceeds the configured maximum (%s)", requestSize, sizeMax), sizeMax,
                        requestSize);
            }
            // N.B. this is eventually closed in MultipartInput processing
            inputStream = new BoundedInputStream(requestContext.getInputStream(), sizeMax) {
                @Override
                protected void onMaxLength(final long maxLen, final long count) throws IOException {
                    throw new FileUploadSizeException(
                            String.format("The request was rejected because its size (%s) exceeds the configured maximum (%s)", count, maxLen), maxLen, count);
                }
            };
        } else {
            inputStream = requestContext.getInputStream();
        }

        final var charset = Charsets.toCharset(fileUploadBase.getHeaderCharset(), requestContext.getCharset());
        multiPartBoundary = fileUploadBase.getBoundary(contentType);
        if (multiPartBoundary == null) {
            IOUtils.closeQuietly(inputStream); // avoid possible resource leak
            throw new FileUploadException("the request was rejected because no multipart boundary was found");
        }

        progressNotifier = new MultipartInput.ProgressNotifier(fileUploadBase.getProgressListener(), requestSize);
        try {
            multiPartInput = MultipartInput.builder().setInputStream(inputStream).setBoundary(multiPartBoundary).setProgressNotifier(progressNotifier).get();
        } catch (final IllegalArgumentException e) {
            IOUtils.closeQuietly(inputStream); // avoid possible resource leak
            throw new FileUploadContentTypeException(String.format("The boundary specified in the %s header is too long", AbstractFileUpload.CONTENT_TYPE), e);
        }
        multiPartInput.setHeaderCharset(charset);
    }