Apache TomEE ships with OpenJPA as the default JPA provider, however any valid JPA 2.0 provider can be used.

The basic steps are:

1. Add the Hibernate jars to <tomee-home>/lib/
2. Configure the webapp or the server to use Hibernate

The atifact versions defined here are just for example, so please feel free to use current library versions.

Webapp Configuration

Any webapp can specify the JPA provider it would like to use via the persistence.xml file, which can be at any of the following locations in a webapp

• WEB-INF/persistence.xml of the .war file
• META-INF/persistence.xml in any jar located in WEB-INF/lib/

A single webapp may have many persistence.xml files and each may use whichever JPA provider it needs.

The following is an example of a fairly common persistence.xml for Hibernate

<persistence version="1.0"
       xmlns="http://java.sun.com/xml/ns/persistence"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
       http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">

  <persistence-unit name="movie-unit">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <jta-data-source>movieDatabase</jta-data-source>
    <non-jta-data-source>movieDatabaseUnmanaged</non-jta-data-source>

    <properties>
      <property name="hibernate.hbm2ddl.auto" value="create-drop"/>
    </properties>
  </persistence-unit>
</persistence>

Note, TomEE will automatically add the following property unless it is explicitly configured:

      <property name="hibernate.transaction.manager_lookup_class"
                value="org.apache.openejb.hibernate.TransactionManagerLookup"/>

Server Configuration

The default JPA provider can be changed at the server level to favor Hibernate over OpenJPA.

Using the <tomee-home>/conf/system.properties file or any other valid means of setting java.lang.System.getProperties(), the following standard properties can set the detault for any persistence.xml file.

• javax.persistence.provider
• javax.persistence.transactionType
• javax.persistence.jtaDataSource
• javax.persistence.nonJtaDataSource

So, for example, Hibernate can become the default provider via setting

CATALINA_OPTS=-Djavax.persistence.provider=org.hibernate.ejb.HibernatePersistence

You must of course add the Hibernate libraries to <tomee-home>/lib/ for this to work.

Hibernate libraries

Jars needed for Hibernate 4.x:

Add:

• <tomee-home>/lib/antlr-2.7.7.jar
• <tomee-home>/lib/dom4j-1.6.1.jar
• <tomee-home>/lib/hibernate-commons-annotations-4.0.1.Final.jar
• <tomee-home>/lib/hibernate-core-4.1.4.Final.jar
• <tomee-home>/lib/hibernate-entitymanager-4.1.4.Final.jar
• <tomee-home>/lib/hibernate-validator-4.3.0.Final.jar
• <tomee-home>/lib/jboss-logging-3.1.0.GA.jar

Remove (optional):

• <tomee-home>/lib/asm-3.2.jar
• <tomee-home>/lib/openjpa-2.2.0.jar

Ehcache (optional)

To use Hibernate with Ehcache, add:

• <tomee-home>/lib/hibernate-ehcache-4.1.4.Final.jar
• <tomee-home>/lib/ehcache-core-2.5.1.jar
• <tomee-home>/lib/ehcache-terracotta-2.5.1.jar
• <tomee-home>/lib/terracotta-toolkit-1.4-runtime-4.1.0.jar

Infinispan (optional)

To use Infinispan cache (default Hibernate 2nd level cache) you need the below jars:

    org.infinispan:infinispan-core:5.1.4.FINAL
    org.hibernate:hibernate-infinispan:${hibernate.core.version}
    org.jgroups:jgroups:3.0.9.Final
    org.jboss.marshalling:jboss-marshalling-river:1.3.11.GA:
    org.jboss.marshalling:jboss-marshalling:1.3.11.GA
    org.codehaus.woodstox:woodstox-core-asl:4.1.1
    org.codehaus.woodstox:stax2-api:3.1.1
    org.rhq.helpers:rhq-pluginAnnotations:3.0.4
    org.jboss.logmanager:jboss-logmanager:1.2.2.GA

There are many guides on how to use 2nd level cache with JPA 2. You can remove OpenJPA jar so less jars are in <tomee-home>/lib folder. Also, be sure to put your Database JDBC driver in <tomee-home>/lib.

The actual Maven dependencies for your project can be added in the usual way:

    <!-- Hibernate -->      
    <dependency>
        <groupId>antlr</groupId>
        <artifactId>antlr</artifactId>
        <version>2.7.7</version>
    </dependency>       
    <dependency>
        <groupId>dom4j</groupId>
        <artifactId>dom4j</artifactId>
        <version>1.6.1</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate.common</groupId>
        <artifactId>hibernate-commons-annotations</artifactId>
        <version>4.0.5.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>4.2.16.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-ehcache</artifactId>
        <version>4.2.16.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
        <version>4.2.16.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-validator</artifactId>
        <version>4.3.2.Final</version>
    </dependency>
    <dependency>
        <groupId>org.jboss.logging</groupId>
        <artifactId>jboss-logging</artifactId>
        <version>3.1.0.GA</version>
    </dependency>
    <dependency>
        <groupId>org.javassist</groupId>
        <artifactId>javassist</artifactId>
        <version>3.15.0-GA</version>
    </dependency>