Re: Struts - Getter method
On Aug 11, 5:33 pm, Rudi <diaz_ruben2...@yahoo.com> wrote:
On Aug 11, 4:18 pm, Rudi <diaz_ruben2...@yahoo.com> wrote:
On Jul 16, 3:10 pm, Rudi <diaz_ruben2...@yahoo.com> wrote:
On Jul 2, 8:27 pm, "Joe Blow" <nob...@noplace.com> wrote:
"Rudi" <diaz_ruben2...@yahoo.com> wrote in message
news:d3f66ee1-e208-4a48-9243-cd870e9e124d@f24g2000prh.googlegroups.c=
om...
On Jun 28, 3:50 pm, "Joe Blow" <nob...@noplace.com> wrote:
"Rudi28" <rd282...@yahoo.com> wrote in message
news:24ef7d68-1afc-4783-b142-a1161cc781ec@w1g2000prd.googlegroups=
..com...
On Jun 25, 11:54 pm, Lew <l...@lewscanon.com> wrote:
Joe Blow wrote:
Sorry to post the code,
First of all. . .never aplogize for posting the source code=
when you
are
asking for help with a programming problem.
To the OP: We love that you posted source code. It is a goo=
d thing.
This
group loves source code, as a rule.
<logic:iterate name="bookListForm" property="books" id=
="book"
type="com.mycompany.Book">
The JSP Standard Tag Library (JSTL) has largely supplanted th=
e logic:
taglib
from Struts.
<c:forEach>, etc.
<http://java.sun.com/products/jsp/jstl/1.1/docs/tlddocs/index=
..html>
You don't have to get into that right away. Learn logic:iter=
ate and
c:forEach
will make sense, in a different but similar way.
Sun's JSTL tutorial is a good starting place, when you're rea=
dy.
<http://java.sun.com/javaee/5/docs/tutorial/doc/bnakc.html>
--
Lew
Hi guys,
Thanks Joe and Lew for your replies. I'm glad I did the right=
thing
posting the code then.
I implemented the change that Joe suggested, I replaced:
<logic:iterate name="bookListForm" property="books" id="=
book">
with
<logic:iterate name="bookListForm" property="books" id="=
book"
type="com.mycompany.Book">
but I get the following error:
Jun 27, 2008 2:01:21 PM org.apache.catalina.core.ApplicationDi=
spatcher
invoke
SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.ClassCastException: [Ljava.lang.Object;
at org.apache.jsp.jsp.bookList_jsp._jspService(bookList_jsp.ja=
va:133)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.j=
ava:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803=
)
at
org.apache.jasper.servlet.JspServletWrapper.service(JspServlet=
Wrapper.java:
393)
at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet=
..java:
320)
I'm now reading about JSTL to see what I can do in terms of g=
etting
this to work.
Thanks for your help and any other ideas are welcome. Hope th=
at I
can get this
going soon since I need it for a project at work.
Sorry I should have caught this the first time through but I am =
not as
familiar with hibernate. Now that I'm looking again, I don't se=
e
anyplace
where you are actually constructing any Book objects. In your
BookListAction code you have this:
books = session.createQuery("select id, title, author, availab=
le from
Book
t").list();
bookListForm.setBooks(books);
Now if you look at the javadoc api's for the org.hibernate.Query=
class
you'll find the following explanation for the list() method:
"Return the query results as a List. If the query contains multi=
ple
results
pre row, the results are returned in an instance of Object[]."
So in my best estimate, unless there is some hibernate magic at =
work
behind
the scenes here I can't see, you never actually create any
com.mycompany.Book objects.
Hi Joe,
Thanks again for the reply. I'm new at this so it's taking me so=
me
time to get things
going. I appreciate your help.
I think I understand what you're telling me. I'm putting the res=
ult
set of the query
(objects) in a Collection, but it's not a collection of type Book=
..
There's no connection
between the Collection that I defined called books and the actual=
Book
Class.
So maybe I shouldn't have even defined that Collection in the Bo=
ok
Class.
I guess what I need to do is iterate through the result set from=
the
Query, while creating
instances of type Book and setting the attributes of each instanc=
e
accordingly with the
corresponding value from the result set (List). As each instance =
of
the Book object is created,
I need to load those instances in a Collection. Then I would have=
a
Collection of type Book to
go through and write to the jsp page.
Have a nice day and holiday. Hope that you're doing well. I'll t=
ry
to figure out how to do
this and will post again.
Take care,
Ruben
Yes, I think it looks like you have understood me perfectly. I bel=
ieve what
you stated is exactly what is causing your problem.
Hi Joe,
Thanks again for the reply. Hope that you're doing well.
I tried several different variation of things to get the code
working. So far
I haven't succeeded.
Below is the change that I made to the BookListAction.java in order
to get the
value of the items returned from the Query. I understand that it's a
list, but the
list (basically rows with data) seems to have an Object in each index=
..
So it's a
list of Objects where every Object has the 4 values retrieved for a
record in the
database.
To make things simple I added a where clause (for id = 1) so that=
it
matches only
one row. I'm able to display that the size of books2 is 1, but I can'=
t
get to the
values somehow.
I'll appreciate your help or any ideas regarding this problem. The
new code for
the BookListAction.java is shown below. The other files have no
changes.
Thanks again,
Ruben
========================
==========================
==========================
=
BookListAction.java
BookListAction.java
package com.mycompany.struts.action;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.swing.text.html.HTMLDocument.Iterator;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import com.mycompany.Book;
import com.mycompany.struts.form.BookListForm;
import com.mycompany.hibernate.*;
import org.hibernate.*;
import org.hibernate.criterion.Projections;
import java.util.*;
public class BookListAction extends Action {
public ActionForward execute(ActionMapping mapping, ActionFor=
m form,
HttpServletRequest request, HttpServletRespon=
se response) {
BookListForm bookListForm = (BookListForm) form;
SessionFactory factory = null;
Session session = null;
Collection <Book> books = new ArrayList<Book>();
List <Object> books2 = new ArrayList<Object>();
Object books3 = null;
Book book1 = null;
try {
factory = HibernateUtil.getSessionFactory();
session = (Session) factory.openSession();
// The line below works and I can see the values in
debug mode. I added the
// where clause to limit the resultset, but it work=
s
without it too
books2 = (List <Object>) session.createQuery("sel=
ect id,
title, author, available from Book where id = 1 ").list();
// The line below prints the total rows returned
from the query. With the
// where clause, it prints the value 1 since only
one row matches that criteria
System.out.println("Query Size = " + books2.size(=
));
// Below are the different things that I tried in
order to get the value from
// books2. Nothing works.
Object[] firstResult = (Object[]) books2.get(0);
// int id = ((Integer) firstResult[0]).intValue()=
;
String title = ((String) firstResult[1]).toString=
();
System.out.println(id);
System.out.println(title);
// Criteria crit = session.createCriteria(Book.cl=
ass);
// System.out.println("Query Size = " + books2.si=
ze());
// for (int i = 0; i < books2.size(); i++) {
// Book book = (Book) books2.getInt(0);
// }
// for (int i = 0; i < books2.size(); i++) {
// books3 = books2.get(i);
// System.out.println(books3);
// }
// for (int i = 0; i < books2.size(); i++) {
// System.out.println(books2);
// book1 = null;
// book1 = (Book) books2.get(i);
// System.out.println(book1.getTitle());
// }
bookListForm.setBooks(books2);
} finally {
session.close();
}
return mapping.findForward("showList");
}
}
========================
==========================
==========================
=
Hi Joe,
Thanks for the help.
I got things working with Hibernate. The code is in this link:
http://groups.google.com.pk/group/comp.lang.java.programmer/browse_th...
However, I get some problems when trying to display the result in a
jsp. I can...
read more =BB
Hi Everyone,
I actually got this to work finally. The last problem was solved
after
I replaced Strut nested tags with plain Struts iterate tags.
The code is in this link:
http://groups.google.com.pk/group/comp.lang.java.programmer/browse_th...
Thanks again to Joe and everyone else for all the help. :)
Moderator: Please close this thread. Thanks.
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