public static <X, P extends MessageQueryParameter<X>, R extends RequestBody, M extends MessageParameters> X getQueryParameter(
			final HandlerRequest<R, M> request,
			final Class<P> queryParameterClass) throws RestHandlerException {

		return getQueryParameter(request, queryParameterClass, null);
	}
public static < X , P extends MessageQueryParameter < X > , R extends RequestBody , M extends MessageParameters > X getQueryParameter ( final HandlerRequest < R , M > request , final Class < P > queryParameterClass ) throws RestHandlerException { return getQueryParameter ( request , queryParameterClass , null ) ; }
Returns the value of a query parameter, or {@code null} if the query parameter is not set.
@throws RestHandlerException If the query parameter is repeated.