Re: DisplayTag Library Question

From:

Daniel Pitts <newsgroup.spamfilter@virtualinfinity.net>

Newsgroups:

comp.lang.java.programmer

Date:

Mon, 05 Oct 2009 17:03:50 -0700

Message-ID:

<sQvym.39531$6f4.36321@newsfe08.iad>

Arne Vajh?j wrote:

Mongoose wrote:

Hi All,

For some reason I'm having trouble with displaying my list data with
the DisplayTag Library . . . I'm new to Struts (and the
DisplayTagLibrary) so hopefully it's something simple . . .

In my implementation class I have a method that uses Hibernate to get
some data from an Oracle Database. The List (in this case called
"results") is returned to the caller . . . which is a Struts Action.
The first part of this file is shown below as well . . .

public List getDefects( ) throws DatastoreException
{
   List results = null;
   List items = null;

   Session session = null;

    try
    {
         session = sessionFactory.openSession( );
         Query q = session.createQuery("select DefectID, Description,
PriorityID from Defect");
         results = q.list( );
         session.close( );
         }catch( Exception ex ){
         ex.printStackTrace( );
         throw DatastoreException.datastoreError(ex);
     }
         return results;
}

public class TestAction extends Action
{
    public TestAction()
    {
        super();
    }

    public ActionForward execute (ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) throws
Exception
    {

        ActionErrors errors = new ActionErrors();
        ActionForward forward = new ActionForward();
        // return value
        //SubmitForm submitForm = (SubmitForm) form;

        try
        {

            System.out.println("Go Away");

             EricEnhancementServiceImpl E = new
EricEnhancementServiceImpl();
             List results = E.getDefects();

             for (ListIterator iter = results.listIterator();
iter.hasNext
() ; )
              {
                 Object[] row = (Object[])iter.next();
                 Integer id = (Integer)row[0];
                 String desc = (String)row[1];
                 Integer priorityid = (Integer)row[2];
              }

             request.setAttribute("stuff", results);

As you can see in the action the "results" list is stored in
session . . .
The .jsp where I'm just trying to display the results of the data that
is in my list is shown below:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><%@page
    language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>

<%@taglib uri="http://struts.apache.org/tags-html" prefix="html"%>
<%@taglib uri="http://struts.apache.org/tags-bean" prefix="bean"%>
<%@ taglib uri="http://displaytag.sf.net" prefix="display" %>
<%@ taglib uri="http://displaytag.sf.net/el" prefix="displayel" %>

<html:html>
<head>
<title>defect</title>
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1">
</head>
<body>

    <jsp:include page="strutsmenu.jsp"/>

    <display:table name="stuff"/>

</body>
</html:html>

When I try to execute the Struts application I get the memory location
printed instead of the data (like this). As far as I know all .jar
file and .tld files are present.

[Ljava.lang.Object;@64c964c9
[Ljava.lang.Object;@64e164e1
[Ljava.lang.Object;@64f964f9
[Ljava.lang.Object;@650f650f
[Ljava.lang.Object;@65276527
[Ljava.lang.Object;@65406540

Can someone please tell me what I'm doing wrong . . .

Maybe your Defect class should have a toString method.

Arne

Even worse than that, the ooutput suggests an "Object[]" instance is the
actual object being printed. Perhaps dispaytag's documentation would
illuminate the proper usage.

You may have to transform your Object[] rows into actual Strings,
Objects, or (ick) Maps.

--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/>