how to use a list containing the query result with hibernate and display it in jsp

Question

hi everyone,

In my servlet I construct the query like the following:

    net.sf.hibernate.Session s = null;
    net.sf.hibernate.Transaction tx;
    try {
        s= HibernateUtil.currentSession();
        tx=s.beginTransaction();
        Query query = s.createQuery("select  opcemployees.Nom,opcemployees.Prenom,dailytimesheet.TrackingDate,dailytimesheet.Activity," +
                "dailytimesheet.ProjectCode,dailytimesheet.WAName,dailytimesheet.TaskCode," +
                "dailytimesheet.TimeSpent,dailytimesheet.PercentTaskComplete from  Opcemployees opcemployees,Dailytimesheet dailytimesheet  " +
                "where opcemployees.Matricule=dailytimesheet.Matricule  and dailytimesheet.Etat=3 " +
                "group by opcemployees.Nom,opcemployees.Prenom" );  

        List opdts= query.list();
        request.setAttribute("items", opdts);
        request.getRequestDispatcher("EspaceValidation.jsp").forward(request, response);
    } catch (HibernateException e){   e.printStackTrace();}

But in the jsp I can't display the result correctly. I do the following in JSP:

<table>
<c:forEach items="${items}" var="item">
    <tr>
        <td>${item}</td>
    </tr>
</c:forEach>
</table>

thanks for help.

Answer 1

You need to determine the object type of every list item. It should be an existing model object (a Javabean like class with private properties and public getters). The ${item} in JSP would only display its Object#toString() outcome, something like com.packagename.ClassName@hashcode. Or if the toString() method is overridden, then you would see a "human friendly" string. Other way to reveal the type would then be debugging the getClass() of the list item:

System.out.println(opdts.get(0).getClass().getName());

Once the type is known and the property names are known, then you can just access its properties in EL like ${item.someProperty}, ${item.otherProperty}, etcetera.

Update: since the list seems to contain Object[] as every item (thus the list signature is actually List<Object[]>), here's how you could display it in JSP/JSTL:

<table>
    <c:forEach items="${list}" var="objects">
        <tr>
            <c:forEach items="${objects}" var="object">
                <td>${object}</td>
            </c:forEach>
        </tr>
    </c:forEach>
</table>

This does basically the same as following in "raw" Java:

System.out.println("<table>");
for (Object[] objects : list) {
    System.out.println("<tr>");
    for (Object object : objects) {
        System.out.println("<td>" + object + "</td>");
    }
    System.out.println("</tr>");
}
System.out.println("</table>");