hibernate-4-spring
Guide to Hibernate 4 with Spring
1. Overview
This article will focus on setting up Hibernate 4 with Spring – we’ll look at how to configure Spring with Hibernate 4 using both Java and XML Configuration. Parts of this process are of course common to the Hibernate 3 article.
2. Maven
To add the Spring Persistence dependencies to the project pom.xml, please see the article focused on the Spring and Maven dependencies.
Continuing with Hibernate 4, the Maven dependencies are simple:
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.3.6.Final</version>
</dependency>Then, to enable Hibernate to use its proxy model, we need the javassist as well:
<dependency>
<groupId>org.javassist</groupId>
<artifactId>javassist</artifactId>
<version>3.18.2-GA</version>
</dependency>And since we’re going to use MySQL for this tutorial, we’ll also need:
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.32</version>
<scope>runtime</scope>
</dependency>And finally, we are using a proper connection pool instead of the dev-only Spring implementation – the DriverManagerDataSource. We’re using here the Tomcat JDBC Connection Pool:
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-dbcp</artifactId>
<version>7.0.55</version>
</dependency>3. Java Spring Configuration for Hibernate 4
To use Hibernate 4 in a project, a few things have changed on the configuration side when moving from a Hibernate 3 setup.
The main aspect that is different when upgrading from Hibernate 3 is the way to create the SessionFactory with Hibernate 4.
This is now done by using the LocalSessionFactoryBean from the hibernate4 package – which replaces the older AnnotationSessionFactoryBean from the hibernate3 package. The new FactoryBean has the same responsibility – it bootstraps the SessionFactory from annotation scanning. This is necessary because, starting with Hibernate 3.6, the old AnnotationConfiguration was merged into Configuration and so the new Hibernate 4 LocalSessionFactoryBean is using this new Configuration mechanism.
It is also worth noting that, in Hibernate 4, the Configuration.buildSessionFactory method and mechanism have also been deprecated in favor of Configuration.buildSessionFactory(ServiceRegistry) – which the Spring LocalSessionFactoryBean is not yet using.
The Spring Java Configuration for Hibernate 4:
@Configuration
@EnableTransactionManagement
@PropertySource({ "classpath:persistence-mysql.properties" })
@ComponentScan({ "org.baeldung.spring.persistence" })
public class PersistenceConfig {
@Autowired
private Environment env;
@Bean
public LocalSessionFactoryBean sessionFactory() {
LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
sessionFactory.setDataSource(restDataSource());
sessionFactory.setPackagesToScan(
new String[] { "org.baeldung.spring.persistence.model" });
sessionFactory.setHibernateProperties(hibernateProperties());
return sessionFactory;
}
@Bean
public DataSource restDataSource() {
BasicDataSource dataSource = new BasicDataSource();
dataSource.setDriverClassName(env.getProperty("jdbc.driverClassName"));
dataSource.setUrl(env.getProperty("jdbc.url"));
dataSource.setUsername(env.getProperty("jdbc.user"));
dataSource.setPassword(env.getProperty("jdbc.pass"));
return dataSource;
}
@Bean
@Autowired
public HibernateTransactionManager transactionManager(
SessionFactory sessionFactory) {
HibernateTransactionManager txManager
= new HibernateTransactionManager();
txManager.setSessionFactory(sessionFactory);
return txManager;
}
@Bean
public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
return new PersistenceExceptionTranslationPostProcessor();
}
Properties hibernateProperties() {
return new Properties() {
{
setProperty("hibernate.hbm2ddl.auto",
env.getProperty("hibernate.hbm2ddl.auto"));
setProperty("hibernate.dialect",
env.getProperty("hibernate.dialect"));
setProperty("hibernate.globally_quoted_identifiers",
"true");
}
};
}
}4. XML Spring Configuration for Hibernate 4
<context:property-placeholder location="classpath:persistence-mysql.properties" />
<bean id="sessionFactory"
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan" value="org.baeldung.spring.persistence.model" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
</props>
</property>
</bean>
<bean id="dataSource"
class="org.apache.tomcat.dbcp.dbcp.BasicDataSource">
<property name="driverClassName" value="${jdbc.driverClassName}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.user}" />
<property name="password" value="${jdbc.pass}" />
</bean>
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<bean id="persistenceExceptionTranslationPostProcessor"
class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor"/>To bootstrap the XML into the Spring Context, we can use a simple Java Configuration file if the application is configured with Java configuration:
@Configuration
@EnableTransactionManagement
@ImportResource({ "classpath:hibernate4Config.xml" })
public class HibernateXmlConfig{
//
}Alternatively, we can simply provide the XML file to the Spring Context, if the overall configuration is purely XML.
For both types of configuration, the JDBC and Hibernate specific properties are stored in a properties file:
# jdbc.X
jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/spring_hibernate_dev?createDatabaseIfNotExist=true
jdbc.user=tutorialuser
jdbc.pass=tutorialmy5ql
# hibernate.X
hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
hibernate.show_sql=false
hibernate.hbm2ddl.auto=create-drop5. Spring, Hibernate, and MySQL
The Drivers and Dialects supported by Hibernate have been extensively discussed for Hibernate 3 – and everything still applies for Hibernate 4 as well.
6. Usage
At this point, Hibernate 4 is fully configured with Spring and we can inject the raw Hibernate SessionFactory directly whenever we need to:
public abstract class BarHibernateDAO{
@Autowired
SessionFactory sessionFactory;
...
protected Session getCurrentSession(){
return sessionFactory.getCurrentSession();
}
}An important note here is that this is now the recommended way to use the Hibernate API – the older HibernateTemplate is no longer included in the new org.springframework.orm.hibernate4 package as it shouldn’t be used with Hibernate 4.
7. Conclusion
As always, the code presented in this article is available over on Github. This is a Maven based project, so it should be easy to import and run as it is.
