javax.transaction.RollBackException when calling session-bea
Hi,
I'm experiencing antoher problem when trying to call a method of a stateless session-bean from a servlet. The session-bean has the following method:
@Stateless (mappedName="ArticleManager")
public class ArticleManager implements ArticleManagerRemote, ArticleManagerLocal {
@PersistenceContext (unitName="texaco",type=PersistenceContextType.TRANSACTION) EntityManager em;
@TransactionAttribute(TransactionAttributeType.REQUIRED)
public Article testArticles(int i){
Article article=em.find(Article.class, 1);
System.out.println("*********** Article name" + article.getArticle_name());
return article;
}
}
This method is called from the servlet; the session-bean is injected:
public class TestServlet extends HttpServlet {
private @EJB ArticleManagerLocal artman;
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException{
try {
Article article=artman.testArticles(1);
PrintWriter out=res.getWriter();
out.print("<HTML>");
out.print(article.getArticle_name());
out.print("</HTML>");
out.println("Hello, world said davy!");
out.close();
} catch (Exception ex){
System.out.println(ex.printStackTrace());
}
}
}
When I try to call the testArticles method, I'm fetching an article from the underlying mysql-database. In the testArticles()-method itself, the name of the article with id="1" is printed correctly, but in the final stage of the method-call, I get the following error-message:
2007-07-22 17:05:28,906 INFO [STDOUT] *********** Article namecoca cola 2007-07-22 17:05:28,906 DEBUG [org.hibernate.event.def.AbstractFlushingEventListener] processing flush-time cascades 2007-07-22 17:05:28,921 DEBUG [org.hibernate.event.def.AbstractFlushingEventListener] dirty checking collections 2007-07-22 17:05:28,968 DEBUG [org.hibernate.ejb.AbstractEntityManagerImpl] mark transaction for rollback 2007-07-22 17:05:28,968 DEBUG [org.jboss.ejb3.entity.ManagedEntityManagerFactory] ************** closing entity managersession ************** 2007-07-22 17:05:29,031 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[localhost].[/texaco_webapp].[hello]] Servlet.service() for servlet hello threw exception java.lang.RuntimeException: javax.transaction.RollbackException at org.jboss.aspects.tx.TxPolicy.handleEndTransactionException(TxPolicy.java:198) at org.jboss.aspects.tx.TxPolicy.endTransaction(TxPolicy.java:180) at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:87)
As one can see: the name of the article itself is fetched correct, but as soon as the article is returned to the servlet, I get that horrible javax.transaction.RollbackException. Also interesting might be the "root cause" of the problem:
javax.transaction.RollbackException com.arjuna.ats.internal.jta.transaction.arjunacore.TransactionImple.commitAndDisassociate(TransactionImple.java:1192) com.arjuna.ats.internal.jta.transaction.arjunacore.BaseTransaction.commit(BaseTransaction.java:134) com.arjuna.ats.jbossatx.BaseTransactionManagerDelegate.commit(BaseTransactionManagerDelegate.java:87 etc.
I use MySQL 5.0.41, Jboss-5.0.0-Beta2 and mysql-connection-java-5.0.6. Is it possible the warning at startup: The locking scheme is NONE instead of
READ_COMMITTED is set, has something to do with this? And in which configuration-file can I change that setting eventually?
Once again,
thanks for possible answers!
Davy.