Question

Running JBoss 5.1, with Hibernate as the JPA provider. Backed with SQL Server 2008.

I’m receiving an error at server startup, which is java.lang.ClassCastException: org.hibernate.dialect.SQLServerDialect cannot be cast to org.hibernate.dialect.Dialect. Pretty clear message, but I’m baffled as to the underlying cause. I have hibernate-core-3.5.1-Final.jar on the classpath, and the necessary class files are present.

This dialect setting was giving no error in the project when it was being used as a property being passed to a Spring AnnotationSessionFactoryBean, but I’m trying to refactor a piece to straight EJB/JPA. For what it’s worth, here’s my persistence config:

<persistence xmlns="http://java.sun.com/xml/ns/persistence"
version="1.0">
<persistence-unit name="[my name here]">
    <jta-data-source>java:jdbc/[my name here]</jta-data-source>
    <properties>
        <property name="hibernate.show_sql" value="true" />
        <property name="hibernate.dialect" value="org.hibernate.dialect.SQLServerDialect"/>
        <property name="hibernate.cache.use_query_cache" value="true" />
        <property name="hibernate.cache.use_second_level_cache" value="true" />
        <property name="hibernate.cache.provider_class" value="net.sf.ehcache.hibernate.EhCacheProvider" />
    </properties>
</persistence-unit>

I hate these kind of “here’s my config and my stacktrace” questions, but I’ve been poking around on this for an hour and a half and am failing to come up with any new ideas.

Answer 1

The ClassCastException is caused by having two copies of the javax.persistence APIs in your system. When running on JBoss, you are just not supposed to package persistence jar in your application. Remove all the persistence related jar’s from your application and the exception should go away.