/** * Returns the non-empty value of the given required query string parameter. * * <p>If this parameter occurs multiple times in the URL, only the last value is returned and * others are silently ignored. * * @param paramname Name of the query string parameter to get. * @return The value of the parameter. * @throws BadRequestException if this query string parameter wasn't passed or if its last * occurrence had an empty value ({@code &a=}). */ public String getRequiredQueryStringParam(final String paramname) throws BadRequestException { final String value = getQueryStringParam(paramname); if (value == null || value.isEmpty()) { throw BadRequestException.missingParameter(paramname); } return value; }