Re: Unmarshalling with Toplink + Eclipse + MySQL

From:
Arved Sandstrom <dcest61@hotmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Fri, 09 Oct 2009 09:49:18 GMT
Message-ID:
<yGDzm.48201$PH1.31125@edtnps82>
Volker Mueller wrote:

Hi there,

I don't know, if I'm right here in this group - if not please tell me
the better choice. The group c.l.j.beans seams to be dead.

I'm just trying out OC4J-Standallone-10.1.3n in an environment as
described in the subject.

In principle the environment "works" - that means I have a working
Datasource (proven by writing an entity - the same one that I now try to
read back - into the DB).

But: When I try to read the entity back:

<code>
@Stateless
public class BookmarkBean implements BookmarkBeanRemote, BookmarkBeanLocal {

[...]
    @PersistenceContext EntityManager em;

    public void getOneUnitEntry() {
        Unit u = null;

        Query q = em.createQuery("UNIT u from UNIT as u");
// List<?> resultList = q.getResultList();
// for (Object e : resultList) {
// if (e instanceof Unit) {
// u = (Unit) e;
// }
// }

        //return u;
    }
[...]
</code>

I get the Exception that I pasted at the end of this message (on client
side - the server side exception is quite short and doesn't explain
anything for me).

Does anybody know what to do to get it working?

TIA, Bye, Volker

This is the exception I get (no matter what I write as Query String).

java.rmi.UnmarshalException: Error deserializing exception-value:
writing aborted; java.io.NotSerializableException:
persistence.antlr.CommonToken; nested exception is:

[ SNIP ]

Hi, Volker

I could be wrong, but it seems to me that it would indeed matter what
you write as the query string, since if there were no problem with the
query you'd have no exception. The stack trace is indicating that
persistence.antlr.CommonToken is not Serializable - it's not - and the
only reason that token is there is because it's included in exception
information being returned from the invocation of that SLSB method.

Did you try a query string like

"select u from Unit u"?

Arved

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