private String getParam(String paramName, HttpHeaders httpHeaders, MultivaluedMap uriParams) {
        if (uriParams == null || !uriParams.containsKey(paramName)) {
            return httpHeaders.getHeaderString(paramName);
        }

        return (String) uriParams.getFirst(paramName);
    }
Tries to parse a long out of the value.  If the val is blank, it returns -1.
Throws {@link NumberFormatException}

@param val
@return
tika-server/tika-server-core/src/main/java/org/apache/tika/server/core/FetcherStreamFactory.java