This sample application demonstrates how you can run TransactionsEssentials and Hibernate without any form of application server nor even Spring.

It is a simple blueprint application that shows and updates the content of two Derby databases in a single atomic transaction controlled via the JTA API.

Download the sample application here:

• Hibernate3ATE.zip

In the ZIP file you'll find:

• an Ant build.xml file that allows you to build the application.
• a derby-create.bat and a derby-create.sh files. They are used respectively on Windows and Unix to create the two embedded Derby databases. You need run this script before you can run the sample.
• a run.bat and a run.sh files. They are used respectively on Windows and Unix to run the sample.

Notes

• To make the connection pools available to Hibernate a JNDI server is required. You can use any one you wish, this sample uses the one embedded in Tomcat 5.5 as it is lightweight (only 2 jars for a total of 83Kb) and simple to reuse outside Tomcat.
• This simple test consumes 3 connections from each database pool. This is because Hibernate 'aggressively' releases connections acquired by sessions: a connection is acquired for every single query and closed immediately afterwards. Since the datasource is configured in exclusive mode, connections are released only after commit or rollback happened. This has been improved in TransactionsEssentials 3.2 which has long become available…

Java sources

Main.java

package com.atomikos.examples.hibernate;

import java.util.List;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.transaction.UserTransaction;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

import com.atomikos.examples.hibernate.entities.User;
import com.atomikos.jdbc.SimpleDataSourceBean;

public class Main {

   private static UserTransaction userTransaction;
   private static SimpleDataSourceBean dataSource1;
   private static SimpleDataSourceBean dataSource2;

   public static void main(String[] args) throws Exception {
      initDataSources();
      initTransactionManager();
      SessionFactory sf1 = new Configuration().
                   configure("/hibernate1.cfg.xml").buildSessionFactory();
      SessionFactory sf2 = new Configuration().
                   configure("/hibernate2.cfg.xml").buildSessionFactory();

      userTransaction.setTransactionTimeout(60);
      userTransaction.begin();

      try {
         System.out.println("*** DB1 ***");
         doWork(sf1, "user");

         System.out.println("*** DB2 ***");
         doWork(sf2, "user");

         userTransaction.commit();
      }
      catch (Exception ex) {
         ex.printStackTrace();
         userTransaction.rollback();
      }

      sf1.close();
      sf2.close();
      dataSource1.close();
      dataSource2.close();

      System.out.println("Both databases updated successfully");
   }

   /**
    * Perform some work. In this scenario, we get a session from the specified
    * SessionFactory then we create a new user with the specified username
    * then list all users.  
    */
   private static void doWork(SessionFactory sf, String username) {
      Session session = sf.getCurrentSession();
      persistUser(session, username);
      listUsers(session);
      session.close();
   }

   /**
    * Dump all users to stdout using the specified Hibernate session. 
    */
   private static void listUsers(Session session) {
      List users = session.createQuery("from User").list();
      for (int i=0; i<users.size() ;i++) {
         User user = (User) users.get(i);

         System.out.println(user.toString());
      }
   }

   /**
    * Create a new user with specified name using the specified Hibernate session.
    */
   private static void persistUser(Session session, String userName) {
      User u = new User();
      u.setName(userName);
      session.save(u);
   }

   /**
    * Initialize the transaction manager.
    */
   private static void initTransactionManager() {
      userTransaction = new com.atomikos.icatch.jta.UserTransactionImp();
   }

   /**
    * Create the 2 datasources and bind them into the embedded JNDI server.
    */
   private static void initDataSources() throws NamingException {
      Context ctx = new InitialContext();
      dataSource1 = getDataSource_db1();
      ctx.rebind("testDS1", dataSource1);
      dataSource2 = getDataSource_db2();
      ctx.rebind("testDS2", dataSource2);
      ctx.close();
   }

   /**
    * Create the first datasource.
    */
   private static SimpleDataSourceBean getDataSource_db1() {
      SimpleDataSourceBean ds = new SimpleDataSourceBean();
      ds.setUniqueResourceName("derby1");
      ds.setXaDataSourceClassName("org.apache.derby.jdbc.EmbeddedXADataSource");
      ds.setXaDataSourceProperties("databaseName=users1");
      ds.setConnectionPoolSize(3);
      return ds;
   }

   /**
    * Create the second datasource.
    */
   private static SimpleDataSourceBean getDataSource_db2() {
      SimpleDataSourceBean ds = new SimpleDataSourceBean();
      ds.setUniqueResourceName("derby2");
      ds.setXaDataSourceClassName("org.apache.derby.jdbc.EmbeddedXADataSource");
      ds.setXaDataSourceProperties("databaseName=users2");
      ds.setConnectionPoolSize(3);
      return ds;
   }

}

User.java

package com.atomikos.examples.hibernate.entities;

public class User {

   private Long id;
   private String name;

   public Long getId() {
      return id;
   }
   public void setId(Long id) {
      this.id = id;
   }
   public String getName() {
      return name;
   }
   public void setName(String name) {
      this.name = name;
   }

   public String toString() {
      return "a User(id=" + id + ", name=" + name + ")";
   }

}

Configuration files

User.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
   "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
   "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.atomikos.examples.hibernate.entities">

   <class name="User" table="`USERS`">
      <id name="id">
         <generator class="identity"/>
      </id>

      <property name="name" not-null="true" column="`NAME`"/>
   </class>

</hibernate-mapping>

hibernate1.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="connection.datasource">testDS1</property>
        <property name="dialect">org.hibernate.dialect.DerbyDialect</property>

        <property name="current_session_context_class">jta</property>
        <property name="transaction.manager_lookup_class">
           com.atomikos.icatch.jta.hibernate3.TransactionManagerLookup
        </property>
        <property name="transaction.factory_class">
           org.hibernate.transaction.JTATransactionFactory
        </property>
        <property name="connection.release_mode">auto</property>

        <property name="cache.provider_class">
            org.hibernate.cache.NoCacheProvider
        </property>
        <property name="show_sql">true</property>

        <mapping resource="com/atomikos/examples/hibernate/entities/User.hbm.xml"/>
    </session-factory>

</hibernate-configuration>

hibernate2.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="connection.datasource">testDS2</property>
        <property name="dialect">org.hibernate.dialect.DerbyDialect</property>

        <property name="current_session_context_class">jta</property>
        <property name="transaction.manager_lookup_class">
           com.atomikos.icatch.jta.hibernate3.TransactionManagerLookup
        </property>
        <property name="transaction.factory_class">
           org.hibernate.transaction.JTATransactionFactory
        </property>
        <property name="connection.release_mode">auto</property>

        <property name="cache.provider_class">
            org.hibernate.cache.NoCacheProvider
        </property>
        <property name="show_sql">true</property>

        <mapping resource="com/atomikos/examples/hibernate/entities/User.hbm.xml"/>
    </session-factory>

</hibernate-configuration>

jta.properties

com.atomikos.icatch.service=com.atomikos.icatch.standalone.UserTransactionServiceFactory
com.atomikos.icatch.automatic_resource_registration=true
com.atomikos.icatch.console_log_level=DEBUG

jndi.properties

java.naming.factory.initial=org.apache.naming.java.javaURLContextFactory

Required libs

JAR name	Source
antlr-2.7.6.jar	Hibernate 3.2.1
asm.jar	Hibernate 3.2.1
cglib-2.1.3.jar	Hibernate 3.2.1
commons-collections-2.1.1.jar	Hibernate 3.2.1
commons-logging-1.0.4.jar	Hibernate 3.2.1
dom4j-1.6.1.jar	Hibernate 3.2.1
hibernate3.jar	Hibernate 3.2.1
jta.jar	Hibernate 3.2.1
naming-factory.jar	Apache Tomcat 5.5.23
naming-resources.jar	Apache Tomcat 5.5.23
derby-10.2.2.0.jar	Derby 10.2.2.0
derbytools-10.2.2.0.jar	Derby 10.2.2.0
atomikos-util.jar	TransactionsEssentials 3.1.5
transactions-api.jar	TransactionsEssentials 3.1.5
transactions-hibernate3.jar	TransactionsEssentials 3.1.5
transactions-jta.jar	TransactionsEssentials 3.1.5
transactions.jar	TransactionsEssentials 3.1.5