Multiple session in hibernate?

gan.gary · **Joined:** Tue Jun 17, 2008 12:14 am **Posts:** 21

If I have a hibernate apps that need to open multiple connection, how to
do this?

I think should be :
hibernate.cfg.xml

Code:

<?xml version='1.0' encoding='utf-8'?>
    <!DOCTYPE hibernate-configuration PUBLIC    "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
    <hibernate-configuration>
      <session-factory>
        <property name="connection.url">jdbc:sqlserver://PC1:XXXX;database=DB1</property>
        <property name="connection.driver_class">com.microsoft.sqlserver.jdbc.SQLServerDriver</property>
        <property name="connection.username">sa</property>
        <property name="connection.password">P@ssw0rd</property>
        <!-- Set AutoCommit to true -->
        <property name="connection.autocommit">true</property>
        <!-- SQL Dialect to use. Dialects are database specific -->
        <property name="dialect">org.hibernate.dialect.SQLServerDialect</property>
        <!-- Mapping files --> 
      </session-factory>
   <session-factory>
        <property name="connection.url">jdbc:sqlserver://PC2:3751;database=DB2</property>
        <property name="connection.driver_class">com.microsoft.sqlserver.jdbc.SQLServerDriver</property>
        <property name="connection.username">sa</property>
        <property name="connection.password">P@ssw0rd</property>
        <!-- Set AutoCommit to true -->
        <property name="connection.autocommit">true</property>
        <!-- SQL Dialect to use. Dialects are database specific -->
        <property name="dialect">org.hibernate.dialect.SQLServerDialect</property>
        <!-- Mapping files -->
      </session-factory>
    </hibernate-configuration>

But what about java/POJO ?
this is for single connection:

Code:

SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
        session = sessionFactory.openSession(); 

what about multiple?

windbell · **Joined:** Wed Apr 30, 2008 4:46 am **Posts:** 8

For multiple connections you can also create multiple configurations
For example..

Code:

Configuration cfg1 = new Configuration()
.addClass(org.hibernate.auction.Item.class)
.setProperty("hibernate.dialect", "org.hibernate.dialect.Oracle9iDialect");

Code:

Configuration cfg2 = new Configuration()
.addClass(org.hibernate.auction.Vendor.class)
.addClass(org.hibernate.auction.Item.class);

and then create SessionFactory

Code:

SessionFactory sessionFactory1 = cfg1.buildSessionFactory();
SessionFactory sessionFactory2 = cfg2.buildSessionFactory();

windbell · **Joined:** Wed Apr 30, 2008 4:46 am **Posts:** 8

You can use the same POJOs.

gan.gary · **Joined:** Tue Jun 17, 2008 12:14 am **Posts:** 21

Thanks.

But do you know how to do this in JBoss?
I thought it was:

Code:

SessionFactory sessionFactory = (SessionFactory)
ctx.lookup("java:/hibernate/SessionFactory");         
session = sessionFactory.openSession();

SessionFactory sessionFactory2 = (SessionFactory)
ctx.lookup("java:/hibernate/SessionFactory2");          
session2 = sessionFactory2.openSession();

And my "jboss-service.xml":

Code:

<?xml version="1.0" encoding="UTF-8"?>
<server>
    <mbean code="org.jboss.hibernate.jmx.Hibernate" 
           name="jboss.adminguide:name=SessionFactory">
        <attribute name="DatasourceName">java:/DS</attribute>
        <attribute name="Dialect">org.hibernate.dialect.SQLServerDialect</attribute> 
        <attribute name="SessionFactoryName">java:/hibernate/SessionFactory</attribute> 
   <attribute name="QueryCacheEnabled" >true</attribute>
    </mbean>
   <mbean code="org.jboss.hibernate.jmx.Hibernate" name="jboss.adminguide:name=SessionFactory2">
        <attribute name="DatasourceName">java:/DS2</attribute>
        <attribute name="Dialect">org.hibernate.dialect.SQLServerDialect</attribute> 
        <attribute name="SessionFactoryName">java:/hibernate/SessionFactory2</attribute> 
      <attribute name="QueryCacheEnabled" >true</attribute>
    </mbean>
</server> 

Cameron McKenzie · **Posted:** Tue Jun 17, 2008 4:01 pm

Connecting to multiple database should be easily accomplished by using the suggesting above. However, remember that your object model won't be able to span across those multiple databases. To have an object model that spans across multiple databases, you might consider Hibernate Shards.

gan.gary · **Joined:** Tue Jun 17, 2008 12:14 am **Posts:** 21

Cameron McKenzie wrote:

Connecting to multiple database should be easily accomplished by using the suggesting above. However, remember that your object model won't be able to span across those multiple databases. To have an object model that spans across multiple databases, you might consider Hibernate Shards.

Are you talking something about this:

Code:

public SessionFactory createSessionFactory() {
   Configuration prototypeConfig = new Configuration().configure("shard0.hibernate.cfg.xml");
   prototypeConfig.addResource("weather.hbm.xml");
   List<ShardConfiguration> shardConfigs = new ArrayList<ShardConfiguration>();
   shardConfigs.add(buildShardConfig("shard0.hibernate.cfg.xml"));
   shardConfigs.add(buildShardConfig("shard1.hibernate.cfg.xml"));
   shardConfigs.add(buildShardConfig("shard2.hibernate.cfg.xml"));
   ShardStrategyFactory shardStrategyFactory = buildShardStrategyFactory();
   ShardedConfiguration shardedConfig = new ShardedConfiguration(
      prototypeConfig,
      shardConfigs,
      shardStrategyFactory);
   return shardedConfig.buildShardedSessionFactory();
   }

at http://www.hibernate.org/hib_docs/shards/reference/en/html_single/ ?

Cameron McKenzie · **Posted:** Mon Jun 23, 2008 10:43 am

That's exactly what I'm talking about. :)