Ch3 Configuration

Programmatic configuration

hibernate.cfg.xml - place under root of classpath, override property file (see an example at the end)

hibernate.properties - under root of classpath

org.hibernate.cfg.Configuration - the representation of configurations and is used to obtain SessionFactory

• new Configuration()

• .configure() - use the default hibernate.cfg.xml under root classpath

• .configure("xxx.xml") - configure use the specified configuration file

Add mappings (if not by configuration file)

• .addResource("xxx.xml") - add xml mapping file from classpath

• .addClass(org.hibernate.sample.EntitySomething.class) - find the xml besides the class

Set properties (if not by configuration file)

• .setProperty(..., ...) - sets propertie manually

• .setProperties() - set collectively

• file "hibernate.properties" under classpath root

• set system properties (java -Dproperty=value)

• include <property> in hibernate.cfg.xml

Build session factory

• SessionFactory factory = cfg.buildSessionFactory()

JDBC connections

Basics - using direct connection (if not in JEE application server):

hibernate.connection.driver_class = org.postgresql.Driver

hibernate.connection.url = jdbc:postgresql://localhost/mydatabase

hibernate.connection.username = myuser

hibernate.connection.password = secret

hibernate.dialect = org.hibernate.dialect.PostgreSQL82Dialect

Arbitrary connection property can be passed to connection, for example, "hibernate.connection.charSet"

Dialect in most cases can be recognized.

Pooling:

• Use hibernate's own pooling

  • simply set "hibernate.connection.pool_size"

  • not recommended for production use

• Use third parties pooling

  • do not set hibernate.connection.pool_size

  • set third party's pooling options

  • example for c3po below

hibernate.c3p0.min_size=5

hibernate.c3p0.max_size=20

hibernate.c3p0.timeout=1800

hibernate.c3p0.max_statements=50

Use DataSource registered with JNDI in application server

hibernate.connection.datasource datasource JNDI name

hibernate.jndi.url URL of the JNDI provider (optional)

hibernate.jndi.class class of the JNDI InitialContextFactory (optional)

hibernate.connection.username database user (optional)

hibernate.connection.password database user password (optional)

An example:

hibernate.connection.datasource = java:/comp/env/jdbc/test

hibernate.transaction.factory_class = \

org.hibernate.transaction.JTATransactionFactory

hibernate.transaction.manager_lookup_class = \

org.hibernate.transaction.JBossTransactionManagerLookup

hibernate.dialect = org.hibernate.dialect.PostgreSQL82Dialect

Other Properties

Only some interesting ones discussed, others see reference

hibernate.dialect - can be omitted in most cases and hibernate will detect

hibernate.show_sql - true|false, show all sql to console

hibernate.default_schema - qualify table names with schema

hibernate.session_factory_name - generated factory will be bind to the name, e.g. "jndi/composite/name"

hibernate.max_fetch_depth - (recommend 0-3, 0 disables default outer fetch), for outer join fetch for single-ended association (one-to-one, many-to-one)

Integration with Jave EE server

Container managed data source: use JDBC connections provided via JNDI that is managed by container. JTA compatible TransactionManager and ResourceManager take care of transaction. Or can use Hibernate Transaction API.

Automatic JNDI binding. Set "hibernate.session_factory_name"

JTA session binding: Hibernate Session automatic bound to JTA transactions.

JMX deployment

(to be further studied)

Example hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>

<!DOCTYPE hibernate-configuration PUBLIC

"-//Hibernate/Hibernate Configuration DTD//EN"

"http://www.hibernate.org/dtd/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>