Re: Help with JTable ... ClassCastException

From:

Lew <noone@lewscanon.com>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 06 May 2012 20:43:48 -0700

Message-ID:

<jo7gdm$pu2$1@news.albasani.net>

On 05/06/2012 03:03 AM, Luiss wrote:

Hi all,

I'm writing a GUI to show a JTable cointaining data from a db table (after
I'll add also buttons to Add, Update and Delete rows). I need to have
different table fields and not only strings.

I've used Hibernate to do the select and then passed the list to a Vector
containing ConfigPersonale objects (my table bean).

I get this exception running the GUI:

********************************
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException:
com.ale.ts.persistence.ConfigPersonale cannot be cast to java.util.Vector

Don't use 'Vector' anyway, and do perform all GUI work on the Event Dispatch
Thread.

In this code:

public class QueryConfigPersonale {
    private Session session;
    private Query query;
    private List<ConfigPersonale> configPersList;

    //select * from ConfigPersonale
    @SuppressWarnings("unchecked")
    public Vector<ConfigPersonale> getConfigPersonale() {
        session = SessionFactoryUtil.getSessionFactory().getCurrentSession();
        session.beginTransaction();
        query = session.createQuery("from ConfigPersonale");

        configPersList = query.list();
        session.getTransaction().commit();

        return new Vector<ConfigPersonale>(configPersList);
    }
}

you use old-fashioned Hibernate ('Session' instead of 'EntityManager'). Use
the JPA style.

Don't suppress unchecked warnings. That's very bad. How do you know it's safe
to do that? You have absolutely no documentation in your code to explain why
it's safe. That's bad.

The Hibernate query returns a list already. Why convert it to a 'Vector'?

--
Lew
Honi soit qui mal y pense.
http://upload.wikimedia.org/wikipedia/commons/c/cf/Friz.jpg