private ArrayList parseRange()

in src/main/java/org/apache/sling/servlets/get/impl/helpers/StreamRenderer.java [589:692]
68 lines of code
15 McCabe index (conditional complexity)

    private ArrayList<Range> parseRange(
            HttpServletRequest request, HttpServletResponse response, ResourceMetadata metadata) throws IOException {

        // Checking If-Range
        String headerValue = request.getHeader("If-Range");
        if (headerValue != null) {

            long headerValueTime = (-1L);
            try {
                headerValueTime = request.getDateHeader("If-Range");
            } catch (IllegalArgumentException e) {
                // Ignore
            }

            if (headerValueTime == (-1L)) {

                // If the ETag the client gave does not match the entity
                // etag, then the entire entity is returned.
                // Sling: no etag support yet, return full range
                return FULL;

            } else if (metadata.getModificationTime() > (headerValueTime + 1000)) {

                // If the timestamp of the entity the client got is older than
                // the last modification date of the entity, the entire entity
                // is returned.
                return FULL;
            }
        }

        long fileLength = metadata.getContentLength();
        if (fileLength == 0) {
            return FULL;
        }

        // Retrieving the range header (if any is specified)
        String rangeHeader = request.getHeader("Range");
        if (rangeHeader == null) {
            return FULL;
        }

        // bytes is the only range unit supported (and I don't see the point
        // of adding new ones).
        if (!rangeHeader.startsWith("bytes")) {
            failParseRange(response, fileLength, rangeHeader);
            return null;
        }

        rangeHeader = rangeHeader.substring(6);

        // Vector which will contain all the ranges which are successfully
        // parsed.
        ArrayList<Range> result = new ArrayList<>();
        StringTokenizer commaTokenizer = new StringTokenizer(rangeHeader, ",");

        // Parsing the range list
        while (commaTokenizer.hasMoreTokens()) {
            String rangeDefinition = commaTokenizer.nextToken().trim();

            Range currentRange = new Range();
            currentRange.length = fileLength;

            int dashPos = rangeDefinition.indexOf('-');

            if (dashPos == -1) {
                failParseRange(response, fileLength, rangeHeader);
                return null;
            }

            if (dashPos == 0) {

                try {
                    long offset = Long.parseLong(rangeDefinition);
                    currentRange.start = fileLength + offset;
                    currentRange.end = fileLength - 1;
                } catch (NumberFormatException e) {
                    failParseRange(response, fileLength, rangeHeader);
                    return null;
                }

            } else {

                try {
                    currentRange.start = Long.parseLong(rangeDefinition.substring(0, dashPos));
                    if (dashPos < rangeDefinition.length() - 1)
                        currentRange.end =
                                Long.parseLong(rangeDefinition.substring(dashPos + 1, rangeDefinition.length()));
                    else currentRange.end = fileLength - 1;
                } catch (NumberFormatException e) {
                    failParseRange(response, fileLength, rangeHeader);
                    return null;
                }
            }

            if (!currentRange.validate()) {
                failParseRange(response, fileLength, rangeHeader);
                return null;
            }

            result.add(currentRange);
        }

        return result;
    }