How to get select value in a JSP to a servlet ? JAVAEE

Question

first pic here after month reading posts to help me so, kinda excited ! :D I'm currently learning JavaEE in scholl and have a problem to get values from a select box in my JSP file.

Here is what I want to do : get the value from the select box when I click "add to card", put that in a list (in the servlet) et show that list back in my jsp file. I give you the code I have for now (probably kin of ugly, sorry, first days...)

Servlet :

public class CommandeServlet extends HttpServlet {

    private List listePlatsCommandes = new ArrayList();

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doWork(request, response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doWork(request, response);
    }

    private void doWork(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        CommandeModel beanSessionCommande = (CommandeModel) request.getSession().getAttribute("beanSessionCommande");




        if (request.getParameterMap().isEmpty()) {
            beanSessionCommande = new CommandeModel();
        } else if (request.getParameter("submit") != null) {

            listePlatsCommandes.add(request.getParameter("platCommande"));
            Commande com = new Commande(request.getParameter("libelle"), listePlatsCommandes);

            CommandeManagerSingl.getInstance().ajouter(com);

            beanSessionCommande.setCommande(com);


        }
        System.out.println(listePlatsCommandes);
        request.getSession().setAttribute("beanSessionCommande", beanSessionCommande);
        request.getRequestDispatcher("/WEB-INF/commande.jsp").forward(request, response);
    }
}

Model :

public class CommandeModel {

    private List<Plat> plats;
    private Commande commande;

    public CommandeModel() {

        this.plats = new ArrayList<Plat>();
        this.commande = new Commande();
    }

    public List<Plat> getPlats() {
        return plats;
    }

    public void addPlat(Plat plat) {
        plats.add(plat);
    }

    public void setPlats(List<Plat> plats) {
        this.plats = plats;
    }

    public Commande getCommande() {
        return commande;
    }

    public void setCommande(Commande commande) {
        this.commande = commande;
    }
}

JSP file :

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
         pageEncoding="ISO-8859-1" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title>Commande</title>
</head>
<body>
<a href="/PlatServlet">Plats</a> - <a href="/CommandeServlet">Commandes</a>
<h1>Gestion des commandes</h1>

<div>
    <form action="CommandeServlet">

        <select name="listePlats">

            <c:forEach var="plat" items="${beanSessionPlat.listePlats}">
                <option name="platCommande" value=" ${plat.libelle} " selected="selected"> ${plat.libelle} </option>
            </c:forEach>

        </select>

        <input type="submit" value="Add to cart" name="submit">
    </form>
</div>

<div>
    <!-- ICI LA LISTE DE LA COMMANDE -->
<h3>Résumé de la commande :</h3> <br><br>
    <table border="1">

        <c:forEach var="com" items="${beanSessionCommande.plats}">
            <tr>
                <td> ${com} </td>
            </tr>
        </c:forEach>
    </table>
</div>

</body>
</html>

Forgot to say : everything is in Session for now, and i get the select list filled up with a list i get from another JSP file

Thanks a lot for helping :)

Answer 1

As the only <select> tag you have has name equal to listePlats , it will be submitted under this name.

request.getParameter("listePlats") will return the value of the selected option .

By the way, it seems that you mark all options as selected . I doubt this is useful: only one (or none) should be marked as such for a non-multi <select> .

How to get select value in a JSP to a servlet ? JAVAEE

Question

1 answers

solution1
1 ACCPTED 2018-02-24 19:16:43

How to get select value in a JSP to a servlet ? JAVAEE

Question

1 answers

solution1 1 ACCPTED 2018-02-24 19:16:43

solution1
1 ACCPTED 2018-02-24 19:16:43