I have made some progress sorting out general configuration errors from my
Tomcat 6 environment, and can restate the transaction problem in more
specific terms that will hopefully lead more directly to a solution.
The specific errors mentioned in my first post were mainly the result of
Tomcat classloader problems, resulting from various dependent classes
deployed wrongly in the webapp WEB-INF/lib/ directory, Tomcat lib/
directory, or both. Many of the errors raised as a result of these problems
are generic and misleading messages such as 'cannot instantiate class...',
'document error...', etc. (Classloader problems seem to be the root of all
evil with things Tomcat.) However, after fixing these problems I am still
unable to retrieve the JTA transaction properly from Hibernate 3.
I have configured the environment to move the transaction-managed JDBC data
source configuration from Tomcat's server.xml into openejb.xml, as follows.
<Resource id="jdbc/LsBpmDS" type="DataSource">
JdbcDriver com.mysql.jdbc.Driver
JdbcUrl jdbc:mysql://localhost:3306/qadworkflow?autoReconnect=true
UserName ...
Password ...
JtaManaged true
InitialSize 0
MaxActive 20
MaxIdle 20
MinIdle 0
MaxWait -1
</Resource>
My hibernate.cfg.xml configuration is as follows (irrelevant settings
omitted).
<property
name="connection.datasource">java:comp/env/jdbc/LsBpmDS</property>
<!-- Proposed workaround suggested on Hibernate forums to work
around bug in UserTransaction retrieval, that causes stack overflow -->
<property name="jta.UserTransaction">UserTransaction</property>
<property
name="transaction.factory_class">org.hibernate.transaction.JTATransactionFactory</property>
<property
name="hibernate.transaction.manager_lookup_class">org.apache.openejb.hibernate.TransactionManagerLookup</property>
With the above I receive a stack overflow error at runtime when attempting
to retrieve the JTA transaction.
java.lang.StackOverflowError
at java.lang.Character.digit(Unknown Source)
at java.lang.Character.digit(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at java.text.MessageFormat.makeFormat(Unknown Source)
at java.text.MessageFormat.applyPattern(Unknown Source)
at java.text.MessageFormat.<init>(Unknown Source)
at java.text.MessageFormat.format(Unknown Source)
at org.apache.naming.StringManager.getString(StringManager.java:121)
at org.apache.naming.StringManager.getString(StringManager.java:144)
at org.apache.naming.NamingContext.lookup(NamingContext.java:770)
at org.apache.naming.NamingContext.lookup(NamingContext.java:153)
at org.apache.naming.SelectorContext.lookup(SelectorContext.java:137)
at javax.naming.InitialContext.lookup(Unknown Source)
at
org.hibernate.transaction.JTATransactionFactory.getUserTransaction(JTATransactionFactory.java:162)
at
org.hibernate.transaction.JTATransactionFactory.getUserTransaction(JTATransactionFactory.java:172)
at
org.hibernate.transaction.JTATransactionFactory.getUserTransaction(JTATransactionFactory.java:172)
...
Here is an associated nested exception.
java.rmi.RemoteException: The bean encountered a non-application exception;
nested exception is:
java.lang.StackOverflowError
at
org.apache.openejb.core.transaction.EjbTransactionUtil.handleSystemException(EjbTransactionUtil.java:152)
at
org.apache.openejb.core.stateless.StatelessContainer._invoke(StatelessContainer.java:233)
at
org.apache.openejb.core.stateless.StatelessContainer.invoke(StatelessContainer.java:174)
at
org.apache.openejb.core.ivm.EjbObjectProxyHandler.businessMethod(EjbObjectProxyHandler.java:217)
at
org.apache.openejb.core.ivm.EjbObjectProxyHandler._invoke(EjbObjectProxyHandler.java:77)
at
org.apache.openejb.core.ivm.BaseEjbProxyHandler.invoke(BaseEjbProxyHandler.java:281)
I have also tried setting the JNDI context factory to the OpenEJB
implementation by adding the setting below, but it does not change the
error.
<property
name="jndi.class">org.apache.openejb.client.LocalInitialContextFactory</property>
The stack overflow error in itself is well-known Hibernate behavior
resulting from repeated unsuccessful attempts by Hibernate to retrieve the
UserTransaction object. From other postings, I know that Hibernate's
JTATransactionFactory class always attempts to read the UserTransaction
object, regardless of the TransactionManager being used; and that apparently
OpenEJB does not create a UserTransaction object inside its own JNDI store.
Is this the root cause of my problem??
Also, I ran across the class
'org.apache.openejb.tomcat.common.UserTransactionFactory' inside one of the
OpenEJB JAR files, and tried configuring a UserTransaction myself in
server.xml as follows.
<Transaction
factory="org.apache.openejb.tomcat.common.UserTransactionFactory" />
This change seemed to have no effect at runtime. I could not even find any
Tomcat log entries verifying that it was used.
Finally I don't know how relevant it is, but I am also puzzled how Hibernate
is able to retrieve the OpenEJB-managed data source
'java:comp/env/jdbc/LsBpmDS' at all, given that this is the JNDI name used
by Tomcat when it was still configured in server.xml. (It is now
unreferenced in both server.xml or the webapp's context.xml.) My
understanding from other OpenEJB forum postings is that the JNDI name used
by OpenEJB from outside an EJB would be 'java:openejb/Resource/LsBpmDS'.
However, if I change the connection.datasource property value in
hibernate.cfg.xml to ''java:openejb/Resource/LsBpmDS'', I receive a
different JNDI lookup error when using either the OpenEJB JNDI context
factory or the default.
javax.ejb.EJBException: org.hibernate.HibernateException: Could not find
datasource
at
org.apache.openejb.core.stateless.StatelessInstanceManager.getInstance(StatelessInstanceManager.java:212)
at
org.apache.openejb.core.stateless.StatelessContainer.invoke(StatelessContainer.java:165)
at
org.apache.openejb.core.ivm.EjbObjectProxyHandler.businessMethod(EjbObjectProxyHandler.java:217)
at
org.apache.openejb.core.ivm.EjbObjectProxyHandler._invoke(EjbObjectProxyHandler.java:77)
at
org.apache.openejb.core.ivm.BaseEjbProxyHandler.invoke(BaseEjbProxyHandler.java:281)
...
I have reviewed Hibernate, OpenEJB, and Tomcat debug logs and can at least
verify that the Hibernate settings that I have tried are being used at
runtime. However, these logs have not been of much help diagnosing the
problem.
Please suggest config changes that I made need, or point me to any custom
class implementations that might help.
Reza Rahman-2 wrote:
>
> Let me see if I can help here, it'll take me a couple of days,
> though...I'm swamped at the moment. I would think David could help too...
>
> Cheers,
> Reza
> =============================
> Author, EJB 3 in Action
> Expert Group Member, Java EE 6 and EJB 3.1
> Resin EJB 3.1 Lite Container Lead
>
>
> Jacek Laskowski wrote:
>> On Mon, Jan 11, 2010 at 4:32 AM, freeway <f...@qad.com> wrote:
>>
>>
>>> To close this message: I have seen many (rather confusing) posts and
>>> partial
>>> examples regarding the use of the config files persistence.xml,
>>> services-jar.xml, and/or openejb-jar.xml files to define data source
>>> resources, Hibernate properties, and transaction managers more
>>> explicitly
>>> inside OpenEJB. However, it seems to me based on other doc I have read
>>> that
>>> using openejb.xml, ejb-jar.xml, and the native Hibernate files should be
>>> enough for a seemingly straightforward case like this one. If this is
>>> wrong, please steer me in the right direction.
>>>
>>
>> I'm so glad you're building the stack with OpenEJB, but alas I won't
>> be able to help you out with the problem at hand. I hope there're
>> people in the mailing list who will share their findings with similar
>> configurations and will provide a viable solution.
>>
>> Jacek
>>
>>
>
>
>
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