An alternative approach to configuration is to specify a full configuration in
a file named hibernate.cfg.xml
. This file can be used as a
replacement for the hibernate.properties
file or, if both
are present, to override properties.
The XML configuration file is by default expected to be in the root o
your CLASSPATH
. Here is an example:
<?xml version='1.0' encoding='utf-8'?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <!-- a SessionFactory instance listed as /jndi/name --> <session-factory name="java:hibernate/SessionFactory"> <!-- properties --> <property name="connection.datasource">java:/comp/env/jdbc/MyDB</property> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <property name="show_sql">false</property> <property name="transaction.factory_class"> org.hibernate.transaction.JTATransactionFactory </property> <property name="jta.UserTransaction">java:comp/UserTransaction</property> <!-- mapping files --> <mapping resource="org/hibernate/auction/Item.hbm.xml"/> <mapping resource="org/hibernate/auction/Bid.hbm.xml"/> <!-- cache settings --> <class-cache class="org.hibernate.auction.Item" usage="read-write"/> <class-cache class="org.hibernate.auction.Bid" usage="read-only"/> <collection-cache collection="org.hibernate.auction.Item.bids" usage="read-write"/> </session-factory> </hibernate-configuration>
As you can see, the advantage of this approach is the externalization of the
mapping file names to configuration. The hibernate.cfg.xml
is also more convenient once you have to tune the Hibernate cache. Note that is
your choice to use either hibernate.properties
or
hibernate.cfg.xml
, both are equivalent, except for the above
mentioned benefits of using the XML syntax.
With the XML configuration, starting Hibernate is then as simple as
SessionFactory sf = new Configuration().configure().buildSessionFactory();
You can pick a different XML configuration file using
SessionFactory sf = new Configuration() .configure("catdb.cfg.xml") .buildSessionFactory();