here an example of what works in our wildfly 8.x/9.x ejb app:
First of all define all the classes for each persistence-unit in the persistence.xml, unlisted classes can be turned off to disable autodiscovery.
persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="primary">
<jta-data-source>java:jboss/datasources/primary_ds</jta-data-source>
<class>whatever.primary.model.SomeEntity</class>
<exclude-unlisted-classes>true</exclude-unlisted-classes>
<properties> ... </properties>
</persistence-unit>
<persistence-unit name="secondary">
<jta-data-source>java:jboss/datasources/secondary_ds</jta-data-source>
<class>whatever.secondary.model.AnotherEntity</class>
<exclude-unlisted-classes>true</exclude-unlisted-classes>
<properties> ... </properties>
</persistence-unit>
</persistence>
If you use JBoss Developer Studio ignore the warning (it is only an eclipse flaw):
Multiple persistence units defined - only the first persistence unit will be recognized
Resources.java
package whatever.util;
import javax.annotation.Resource;
import javax.enterprise.inject.Produces;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.sql.DataSource;
public class Resources {
@Produces
@PersistenceContext(unitName = "primary")
private EntityManager emPrimary;
@Produces
@PersistenceContext(unitName = "secondary")
private EntityManager emSecondary;
@Produces
@Resource(lookup = "java:jboss/datasources/primary_ds")
private DataSource dsPrimary;
@Produces
@Resource(lookup = "java:jboss/datasources/secondary_ds")
private DataSource dsSecodnary;
}
Dao primary example
package whatever.dao;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
@Stateless
public class DaoPrimaryExample {
@PersistenceContext(unitName = "primary")
private EntityManager em;
public void create(SomeEntity entity) {
em.persist(entity);
}
}
Dao secondary example
package whatever.dao;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
@Stateless
public class DaoSecondaryExample {
@PersistenceContext(unitName = "secondary")
private EntityManager em;
public void create(AnotherEntity entity) {
em.persist(entity);
}
}
IMPORTANT: If you plan to use booth persistence units in same transaction than XA datasources should be used.
