Problem with session in Servet

Question

I have the saida.jsp. It is my page that depending on the option chosen by the user, it is mounted in one way. I have two options for the user verbs and adverbios. In case the user clicks on the option verbs it will be redirected to the page saida.jsp and it will be mounted in a form. The same goes for the option adverbios. My problem is when the user selects the option verbs, then it goes back to page and selects the option adverbios. When this happens, the page adverbios appears as if it were verbs. I’ve looked into it, I’ve been told it’s a session mistake, but I’m not really a session expert.

if(str.equals("verbos")){
            extrair = Extrair.verbos();
            verbos.contVerb = extrair.contverb;
            request.getSession().setAttribute("verbos", verbos);
            rd = request.getRequestDispatcher("saida.jsp");
}
else if(str.equals("adverbios")){
            extrair = Extrair.adverbios();
            adverbios.contAdv = extrair.contadv;
            request.getSession().setAttribute("adverbios", adverbios);
            rd = request.getRequestDispatcher("saida.jsp");
}

That’s the treatment I said. I don’t know how to handle session, someone could enlighten me?

Answer 1

You are putting the attributes in the session, but one is not cleaning the other. When accessing both pages, both "adverbios" and "verbs" attributes will have been set in the session and both will be visible in the saida.jsp, as the request will receive the session as the previous request left it.

The solution is to remove the unwanted attribute:

if(str.equals("verbos")){
        extrair = Extrair.verbos();
        verbos.contVerb = extrair.contverb;
        request.getSession().setAttribute("verbos", verbos);
        request.getSession().setAttribute("adverbios", null); // Remove o "adverbios".
        rd = request.getRequestDispatcher("saida.jsp");
}
else if(str.equals("adverbios")){
        extrair = Extrair.adverbios();
        adverbios.contAdv = extrair.contadv;
        request.getSession().setAttribute("adverbios", adverbios);
        request.getSession().setAttribute("verbos", null); // Remove o "verbos".
        rd = request.getRequestDispatcher("saida.jsp");
}

By the way, I see this is a remake of your other question. Since you’ve designed this one in a much better way, it’s much easier to answer. :)