Hibernate how to enabled 2 cache.

[Cristian Daniel Ortiz Cuellar]

Hi Guys. i am learning hibernate like i put it in my last post.

i am trying to enabled hibernate 2 cache..
here is my hibernate.cfg.xml.

<?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="hibernate.connection.datasource">jdbc/Datasource</property>
    <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>      
    <property name="hibernate.show_sql">false</property>
    <mapping class="org.com.Classes.Sistema"/>
    <mapping class="org.com.Models.Laboratorios"/>
    <mapping class="org.com.Models.Lineas"/>
    <mapping class="org.com.Models.Sucursales"/>
  </session-factory>
</hibernate-configuration>

i have a javabean like this.

@Entity
@Immutable
@Cache(usage = CacheConcurrencyStrategy.READ_ONLY)
@Table(name="labor")
public class Laboratorios implements java.io.Serializable
{
    @Id
    @Column(name="codigolabor",nullable=false,updatable=false,length=10)
    private String Id;
    @Column(name="nombrelabor",nullable=false,updatable=false,length=40)
    private String Nombre;
}

i am getting this error GRAVE: Initial SessionFactory creation failed.org.hibernate.HibernateException: Could not instantiate cache implementation.

my question is. does hibernate have a proper 2 cache. if it's so? how can i enabled?
or do i have to implements a 2 cache vendor provider..
thanks a lot