How to externalize properties from JPAs persistence.xml?
Solution 1
As an alternative to your current approach and since you're using Hibernate, you could use Hibernate to configure JPA by declaring a hibernate.cfg.xml
file using the hibernate.ejb.cfgfile
property, like this:
<persistence>
<persistence-unit name="manager1" transaction-type="JTA">
<jta-data-source>java:/DefaultDS</jta-data-source>
<properties>
<property name="hibernate.ejb.cfgfile" value="/hibernate.cfg.xml"/>
</properties>
</persistence-unit>
</persistence>
My understanding is that the hibernate.cfg.xml
is just supposed to be on the classpath (so it could be outside the packaged archive).
References
- Hibernate Entity Manager Reference Guide
Solution 2
Just found a an alleged way for EclipseLink users. There is "eclipselink.persistencexml" which has a default value of
public static final String ECLIPSELINK_PERSISTENCE_XML_DEFAULT = "META-INF/persistence.xml";
but it can't be overridden although the docs say it can be...
/**
* The <code>"eclipselink.persistencexml"</code> property specifies the full
* resource name to look for the persistence XML files in. If not specified
* the default value defined by {@link #ECLIPSELINK_PERSISTENCE_XML_DEFAULT}
* will be used.
* <p>
* IMPORTANT: For now this property is used for the canonical model
* generator but it can later be used as a system property for customizing
* weaving and application bootstrap usage.
* <p>
* This property is only used by EclipseLink when it is locating the
* configuration file. When used within an EJB/Spring container in container
* managed mode the locating and reading of this file is done by the
* container and will not use this configuration.
*/
Solution 3
I used this mechanism, seems to work for most of the properties, had issues with non-jta-data-source.
Solution 4
If you are using Spring to manage and inject entity manager, then it is possible to implement org.springframework.orm.jpa.persistenceunit.PersistenceUnitPostProcessor and pass on external properties. I could successfully externalize all properties from persistence.xml using this.
Comments
-
stacker over 4 years
I would like to put some of the hibernate configuration in a property file to make it editable without build and deploy.
I tried to solve my problem by following the instructions from Create JPA EntityManager without persistence.xml configuration file
app.properties:
hibernate.show_sql=true hibernate.dialect=org.hibernate.dialect.MySQLDialect hibernate.hbm2ddl.auto=validate hibernate.show_sql=true hibernate.format_sql=true hibernate.default_schema=myschema
persistence.xml
<?xml version="1.0" encoding="UTF-8"?> <!-- Persistence deployment descriptor for dev profile --> <persistence 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" version="1.0"> <persistence-unit name="pu"> <provider>org.hibernate.ejb.HibernatePersistence</provider> <jta-data-source>jdbc/appDatasource</jta-data-source> <properties> <property name="jboss.entity.manager.factory.jndi.name" value="java:/appEntityManagerFactory"/> </properties> </persistence-unit> </persistence>
In the initialization code the application executes the following sequence, (which finds the properties),
Properties props = new Properties(); InputStream is = ClassLoader.getSystemResourceAsStream( "app.properties" ); props.load( is ); Persistence.createEntityManagerFactory( "pu", props );
but fails with the error message:
INFO [SessionFactoryImpl] building session factory INFO [SessionFactoryObjectFactory] Not binding factory to JNDI, no JNDI name configured ERROR [STDERR] javax.persistence.PersistenceException: [PersistenceUnit: pu] Unable to build EntityManagerFactory
Does anyone have an idea what could be wrong with my configuration?
Versions: JBoss 4.3 Seam: 2.1.2
EDIT:
JBoss JNDI enlists "pu" as persistence unit:
persistence.units:ear=app.ear,jar=app.jar,unitName=pu (class: org.hibernate.impl.SessionFactoryImpl)