1. Copy the required Hibernate .jars to <tomee-home>/lib
According to the documentation ( http://tomee.apache.org/tomee-and-hibernate.html ), the following ones are sufficient and in fact they worked for me:
<tomee-home>/lib/antlr-2.7.7.jar
<tomee-home>/lib/dom4j-1.6.1.jar
<tomee-home>/lib/hibernate-commons-annotations-4.0.2.Final.jar
<tomee-home>/lib/hibernate-core-4.2.21.Final.jar
<tomee-home>/lib/hibernate-entitymanager-4.2.21.Final.jar
<tomee-home>/lib/hibernate-validator-4.3.2.Final.jar
<tomee-home>/lib/javassist-3.18.1-GA.jar
<tomee-home>/lib/jboss-logging-3.1.0.GA.jar
All these .jars are contained in the Hibernate ORM 4.2.x download ( http://hibernate.org/orm/ ), except for the Hibernate Validator, which is a separate download ( http://hibernate.org/validator/ ).
2. Edit your pom.xml
Using the javaee-api maven artifact with a scope of provided you can now use the JPA specification in your project. However, if you have been using some Hibernate specific features, classes or annotations before, you can still refer to Hibernate in your pom.xml to match those dependencies:
<!-- JPA spec (required) -->
<dependencies>
<dependency>
<groupId>org.apache.openejb</groupId>
<artifactId>javaee-api</artifactId>
<version>6.0-4</version>
<scope>provided</scope>
</dependency>
<!-- Hibernate specific features (only if needed) -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>4.2.21.Final</version>
<scope>provided</scope>
</dependency>
3. Define your database connection
Edit <tomee-home>/conf/tomee.xml:
<Resource id="myJtaDatabase" type="DataSource">
JdbcDriver com.mysql.jdbc.Driver
JdbcUrl jdbc:mysql://localhost:3306/my_dbname?autoReconnect=true
UserName foo
Password bar
validationQuery = SELECT 1
JtaManaged true
</Resource>
You can also put the above <Resource>...</Resource> definition into WEB-INF/resources.xml and ship it with your application instead:
<?xml version="1.0" encoding="UTF-8"?>
<resources>
<!-- Put <Resource> elements here -->
<resources>
4. JTA Datasource
Now that you told TomEE how to establish a connection, define a JTA datasource in /src/main/java/META-INF/persistence.xml:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0"
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_2_0.xsd">
<persistence-unit name="my_persistence_unit">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<jta-data-source>java:openejb/Resource/myJtaDatabase</jta-data-source>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect" />
<!-- As many hibernate properties as you need, some examples: -->
<property name="hibernate.show_sql" value="false" />
<property name="hibernate.format_sql" value="true" />
<!-- Drop and then re-create the database schema (don't do this in production) -->
<property name="hibernate.hbm2ddl.auto" value="update" />
</properties>
</persistence-unit>
</persistence>
5. Start using JPA
Obtain an EntityManager in a CDI bean or EJB like this:
@PersistenceContext(unitName = "my_persistence_unit")
private EntityManager em;
Final Notes
Hibernate versions 4.3+
I am using Hibernate 4.2.21 (JPA 2.0, Java EE 6) along with TomEE 1.7.2. Any TomEE 1.7.x, 1.6.x and 1.5.x will work. However, you cannot use Hibernate 4.3+ (JPA 2.1 / Java EE 7), as TomEE 1.7.x and below only support Java EE 6. If you really want to use Java EE 7 features along with TomEE, this blog post might be helpful: http://rmannibucau.wordpress.com/2013/07/19/little-tip-to-help-you-to-test-javaee-7-in-tomee-with-tomee-maven-plugin/
TomEE 1.5.x
TomEE 1.5.x already includes a javassist-<version>.jar, so you don't have to copy one.
