After quite few fixes during my migration from 2.1.7 to 3.0.2, I run into this exception and don't see how I can fix it. Had a look at the migration documentation, I can't find any coding problem. It seems to me that the exception class is not in the Hibernate jar file.

Hibernate version: 3.0.2

Full stack trace of any exception that occurs:
2005-05-06 12:58:25,718 ERROR org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/xyz].[xyz] - Servlet.service() for servlet xyz threw exception
java.lang.NoClassDefFoundError: antlr/ANTLRException
at org.hibernate.hql.ast.ASTQueryTranslatorFactory.createQueryTranslator(ASTQueryTranslatorFactory.java:27)
at org.hibernate.impl.SessionFactoryImpl.createQueryTranslators(SessionFactoryImpl.java:352)
at org.hibernate.impl.SessionFactoryImpl.getQuery(SessionFactoryImpl.java:418)
at org.hibernate.impl.SessionImpl.getQueries(SessionImpl.java:822)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:782)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:74)
at org.springframework.orm.hibernate3.HibernateTemplate$30.doInHibernate(HibernateTemplate.java:772)
at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:310)
at org.springframework.orm.hibernate3.HibernateTemplate.findByNamedParam(HibernateTemplate.java:763)

Name and version of the database you are using:

PostgreSQL 8.0.2

add antlr-2.7.5H3.jarr (from hibernate distibution) in your classpath.3.0.2 have new antlr jar .
delete old antlr if you have one

Thanks very much Snpesnpe.

I didn't recoganze it is an external library problem.