Retrieve Vaadin 6 Url Parameter

General
1

E.g. http://localhost:8080/ffl-client?aaa=bbb

i want to retrieve the value for “aaa”. How can i do this in Vaadin 6.8.?

2

getContext().addTransactionListener(new TransactionListener() {
@Override
public void transactionEnd(final Application application, final Object transactionData) {
}

        @Override
        public void transactionStart(final Application application, final Object transactionData) {
            HttpServletRequest httpServletRequest = (HttpServletRequest) transactionData;
            if (request.getParameter("aaa") != null) {
             todo
            }