I'm trying to use the BitMechanic JDBC pool when creating Hibernate Sessions.,

My code in the Factory reads:


My SqlMan.getConnection() class returns a java.sql.Connection. I'm getting an



Any ideas?

Hibernate version:
2.1.6
Mapping documents:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>

<class name="com.solidstategroup.forum.Thread" table="H_Thread">
<meta attribute="class-description">
Represents a thread
</meta>

<id name="id" type="int">
<meta attribute="scope-set">protected</meta>
<generator class="native"/>
</id>

<property name="subject" type="string" length="275" not-null="true"/>
<property name="numberOfViews" type="int" not-null="true"/>
<property name="numberOfReplies" type="int" not-null="true"/>
</class>

</hibernate-mapping>

Code between sessionFactory.openSession() and session.close():
Session session = HibernateSession.currentSession();
Transaction tx = null;

try {
tx = session.beginTransaction();
Thread t = new Thread("Test", 5, 2);
session.save(t);
tx.commit();
} catch (Exception e) {
Logger.addError(e.toString());
} finally {
try {
session.close();
} catch (HibernateException e) {
Logger.addError(e.toString());
}
}

Full stack trace of any exception that occurs:
0 [main] INFO cfg.Environment - Hibernate 2.1.6
0 [main] INFO cfg.Environment - loaded properties from resource hibernate.properties: {hibernate.connection.username=root, hibernate.connection.password=spit69fire, hibernate.cglib.use_reflection_optimizer=true, hibernate.dialect=net.sf.hibernate.dialect.MySQLDialect, hibernate.connection.url=jdbc:mysql://192.168.1.2:3306/test, hibernate.connection.driver_class=com.mysql.jdbc.Driver}
0 [main] INFO cfg.Environment - using CGLIB reflection optimizer
0 [main] INFO cfg.Configuration - configuring from file: hibernate.cfg.xml
125 [main] INFO cfg.Configuration - Mapping resource: com/solidstategroup/forum/Thread.hbm.xml
266 [main] INFO cfg.Binder - Mapping class: com.solidstategroup.forum.Thread -> H_Thread
360 [main] INFO cfg.Configuration - Configured SessionFactory: null
360 [main] INFO cfg.Configuration - processing one-to-many association mappings
360 [main] INFO cfg.Configuration - processing one-to-one association property references
360 [main] INFO cfg.Configuration - processing foreign key constraints
391 [main] INFO dialect.Dialect - Using dialect: net.sf.hibernate.dialect.MySQLDialect
407 [main] INFO cfg.SettingsFactory - Maximim outer join fetch depth: 2
407 [main] INFO cfg.SettingsFactory - Use outer join fetching: true
407 [main] INFO connection.DriverManagerConnectionProvider - Using Hibernate built-in connection pool (not for production use!)
407 [main] INFO connection.DriverManagerConnectionProvider - Hibernate connection pool size: 20
407 [main] INFO connection.DriverManagerConnectionProvider - using driver: com.mysql.jdbc.Driver at URL: jdbc:mysql://192.168.1.2:3306/test
407 [main] INFO connection.DriverManagerConnectionProvider - connection properties: {user=root, password=spit69fire}
407 [main] INFO transaction.TransactionManagerLookupFactory - No TransactionManagerLookup configured (in JTA environment, use of process level read-write cache is not recommended)
422 [main] INFO cfg.SettingsFactory - Use scrollable result sets: true
422 [main] INFO cfg.SettingsFactory - Use JDBC3 getGeneratedKeys(): true
422 [main] INFO cfg.SettingsFactory - Optimize cache for minimal puts: false
422 [main] INFO cfg.SettingsFactory - Query language substitutions: {}
422 [main] INFO cfg.SettingsFactory - cache provider: net.sf.hibernate.cache.EhCacheProvider
438 [main] INFO cfg.Configuration - instantiating and configuring caches
563 [main] INFO impl.SessionFactoryImpl - building session factory
860 [main] INFO impl.SessionFactoryObjectFactory - Not binding factory to JNDI, no JNDI name configured
java.lang.AbstractMethodError: com.bitmechanic.sql.PooledConnection.prepareStatement(Ljava/lang/String;I)Ljava/sql/PreparedStatement;
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at net.sf.hibernate.util.GetGeneratedKeysHelper.prepareStatement(GetGeneratedKeysHelper.java:39)
at net.sf.hibernate.impl.BatcherImpl.getPreparedStatement(BatcherImpl.java:254)
at net.sf.hibernate.impl.BatcherImpl.prepareStatement(BatcherImpl.java:61)
at net.sf.hibernate.persister.EntityPersister.insert(EntityPersister.java:525)
at net.sf.hibernate.persister.EntityPersister.insert(EntityPersister.java:432)
at net.sf.hibernate.impl.ScheduledIdentityInsertion.execute(ScheduledIdentityInsertion.java:29)
at net.sf.hibernate.impl.SessionImpl.doSave(SessionImpl.java:932)
at net.sf.hibernate.impl.SessionImpl.doSave(SessionImpl.java:857)
at net.sf.hibernate.impl.SessionImpl.saveWithGeneratedIdentifier(SessionImpl.java:775)
at net.sf.hibernate.impl.SessionImpl.save(SessionImpl.java:738)
at com.solidstategroup.forum.Test.main(Test.java:21)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:78)
Exception in thread "main"
Process finished with exit code 1

Name and version of the database you are using:
MySQL 4.0.20

The generated SQL (show_sql=true):
--
Debug level Hibernate log excerpt:
--

Are you using JDK 1.3.1?
If true try to recompile Hibernate on this JDK.

I'm using JDK 1.4.2.

So your driver seems not been compliant with the .sql package of the JDK 1.4.2

I'm using the latest MySQL Connector, version 3.0.15. Could it be that the Connection Pooling code needs recompiling?

Your connection pool does not support JDBC3, apparently. Use a better connection pool, or yell at BitMechanic to fix it.

For a workaround, disable use of getGeneratedKeys() in hibernate.properties.

P.S. Why do we always seem to get the blame when connection pools and JDBC drivers are broken??

Apologies. I've just started learning Hibernate and really think it is an incredible API. I guess with the number of JDBC drivers and DBMS's there is a large potential for nasty little errors like this.

If I were to recompile the BitMechanic source code, would that help me?

Probably not. You would need to actually change the src to add support for the extra JDBC3 methods.

Ok. Thanks for your help. Maybe it's time to drop the BitMechanic stuff and use the Jakarta DBCP.

Are there any guides on best practise for things like Connection Pooling with respect to Hibernate?

prefer c3p0 or proxool
all is documented on c3p0 and proxool site and of course hibernate wiki gives hints

Thanks for the tips. Is there any reason as to why you prefer these two APIs?

Just experience, there seem to be more problems comming up with DBCP than with the other two.

you can also check
http://forum.hibernate.org/viewtopic.php?t=931132