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Hibernate version: 3.2.3ga

Full stack trace of any exception that occurs:
java.lang.NullPointerException
at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:505)
at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:423)
at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:139)
at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1547)
at org.hibernate.loader.Loader.doQuery(Loader.java:673)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236)
at org.hibernate.loader.Loader.doList(Loader.java:2220)
at org.hibernate.loader.Loader.listUsingQueryCache(Loader.java:2136)
at org.hibernate.loader.Loader.list(Loader.java:2096)
at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:94)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1569)
at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:283)
at org.hibernate.impl.CriteriaImpl.uniqueResult(CriteriaImpl.java:305)
at de.vdb.testapp.dao.ApplicationPropertyDaoBase$2.doInHibernate(ApplicationPropertyDaoBase.java:418)
at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:419)
at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:339)
at de.vdb.testapp.dao.ApplicationPropertyDaoBase.findByUkProp(ApplicationPropertyDaoBase.java:408)
at de.vdb.testapp.dao.ApplicationPropertyDaoBase.findByUkProp(ApplicationPropertyDaoBase.java:380)
at de.vdb.testapp.dao.ApplicationPropertyDao.findByName(ApplicationPropertyDao.java:51)
at de.vdb.testapp.dao.ApplicationPropertyDao.findBooleanValue(ApplicationPropertyDao.java:170)

Name and version of the database you are using: Oracle 10g (

We have some strange problem with Hibernate and Oracle 10g. Under heavy load Hibernate tends to loose the database connection from time to time (see the stacktrace).

From the Hibernate sources:


The connection pool configuration in Tomcat:


Obviously the connection is null.

This might be a problem with Hibernate, with the connection pool (we use Tomcat's internal connection pooling) or the database driver.
After short time the connection is available again.

Any hints ?

I am also getting the similar type of exception? Could you please let me know, what needs to be done for this? i am using hibernate 3.2.3ga version.

jdbc connections are not reliable, that's why you shouldn't rely on Tomcat alone.
If you need to use Tomcat you'll have to use a connection pool like c3p0 (there are lots of guides online to use hibernate with c3p0).
Otherwise, use an application server, there you can configure nice settings to use reliable and monitored connections.

Sorry I am using resin server (application server), not tomcat.
The following db configuration, we are using in resin.
<resource jndi-name="financedb" type="oracle.jdbc.pool.OracleDataSource">
<init><url>DB URL</url>
<user>user name</user>
<password>pass word</password>
<fast-connection-failover-enabled>true</fast-connection-failover-enabled>
<connection-caching-enabled>true</connection-caching-enabled>
<connection-cache-properties>
MinLimit=0
MaxLimit=10
InitialLimit=1
InactivityTimeout=1800
AbandonedConnectionTimeout=900
ConnectionWaitTimeout=60
ValidateConnection=true
Validate-connection-statement="select 1 from dual;"
</connection-cache-properties>
</init>
</resource>

while I don't know Resin, this seems to make sense:

Which hibernate version? it shouldn't really throw a nullpointer there.

Which hibernate version? it shouldn't really throw a nullpointer there. --
I am using 3.2.3ga -- Hibernate Version -- I am getting the nullpointer exception spordically.

By using these two tags we are validating, whether the connection is valid or not...
ValidateConnection=true
Validate-connection-statement="select 1 from dual;"

ok sorry for asking I was assuming you where using something newer than the original thread poster.
That's very old! you should try upgrading, there have been thousands of improvements and bugfixes after that.

Without upgrading the hibernate version..can't we able to fix this issue? Because if i upgrade the version, we have to test the all the scenerios...This is very huge.

And one morething, I am getting the exception in 505 line.



Could you please let me know, why i am getting the Null Pointer Exception in this line?

Any hints?

of course it means the connection was null; it's hard to track why; you might want to debug it.
Anyway even if we could fix that, you would have to change version.


that's why you should have automated tests, or you will be locked forever in the fear of changing any library.

Anyway you might want to at least upgrade to the latest supported hibernate 3.2.X instead of switching to 3.5.2 (which is the latests), so you should minimize risk and still get a load of issues fixed. There's a 3.2.7 and there are also extra-stable supported packages provided by Red Hat support which contain only backported fixes and attempt to avoid all breaking changes (I don't work for RH, but this might be a solution for you).

Try a drop-in of 3.2.7; remember to upgrade also depending libraries from the 3.2.7 download package.

Can we know, what are the changes have done in 3.2.7 vesrion?

Do we have any fix for this Null Pointer exception or memory leak in 3.2.7 version?

All changes, bugfixes and new features are tracked on JIRA.