1. Overview
This article will focus on setting up Hibernate 3 with Spring – we’ll look at how to use both XML and Java configuration to set up Spring 3 with Hibernate 3 and MySQL.
2. Java Spring Configuration for Hibernate 3
Setting up Hibernate 3 with Spring and Java config is straightforward:
import java.util.Properties;
import javax.sql.DataSource;
import org.apache.tomcat.dbcp.dbcp.BasicDataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.Environment;
import org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor;
import org.springframework.orm.hibernate3.HibernateTransactionManager;
import org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import com.google.common.base.Preconditions;
@Configuration
@EnableTransactionManagement
@PropertySource({ "classpath:persistence-mysql.properties" })
@ComponentScan({ "org.baeldung.spring.persistence" })
public class PersistenceConfig {
@Autowired
private Environment env;
@Bean
public AnnotationSessionFactoryBean sessionFactory() {
AnnotationSessionFactoryBean sessionFactory = new AnnotationSessionFactoryBean();
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
public HibernateTransactionManager transactionManager() {
HibernateTransactionManager txManager = new HibernateTransactionManager();
txManager.setSessionFactory(sessionFactory().getObject());
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"));
}
};
}
}Compared to the XML Configuration – described next – there is a small difference in the way one bean in the configuration access another. In XML there is no difference between pointing to a bean or pointing to a bean factory capable of creating that bean. Since the Java configuration is type-safe – pointing directly to the bean factory is no longer an option – we need to retrieve the bean from the bean factory manually:
txManager.setSessionFactory(sessionFactory().getObject());
3. XML Spring Configuration for Hibernate 3
Similarly, we can set up Hibernate 3 with XML config as well:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd">
<context:property-placeholder location="classpath:persistence-mysql.properties" />
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<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="txManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<bean id="persistenceExceptionTranslationPostProcessor"
class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor"/>
</beans>Then, this XML file is bootstrapped into the Spring context using a @Configuration class:
@Configuration
@EnableTransactionManagement
@ImportResource({ "classpath:persistenceConfig.xml" })
public class PersistenceXmlConfig {
//
}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-drop
4. Spring, Hibernate and MySQL
The example above uses MySQL 5 as the underlying database configured with Hibernate – however, Hibernate supports several underlying SQL Databases.
4.1. The Driver
The Driver class name is configured via the jdbc.driverClassName property provided to the DataSource.
In the example above, it is set to com.mysql.jdbc.Driver from the mysql-connector-java dependency we defined in the pom, at the start of the article.
4.2. The Dialect
The Dialect is configured via the hibernate.dialect property provided to the Hibernate SessionFactory.
In the example above, this is set to org.hibernate.dialect.MySQL5Dialect as we are using MySQL 5 as the underlying Database. There are several other dialects supporting MySQL:
- org.hibernate.dialect.MySQL5InnoDBDialect – for MySQL 5.x with the InnoDB storage engine
- org.hibernate.dialect.MySQLDialect – for MySQL prior to 5.x
- org.hibernate.dialect.MySQLInnoDBDialect – for MySQL prior to 5.x with the InnoDB storage engine
- org.hibernate.dialect.MySQLMyISAMDialect – for all MySQL versions with the ISAM storage engine
Hibernate supports SQL Dialects for every supported Database.
5. Usage
At this point, Hibernate 3 is fully configured with Spring and we can inject the raw Hibernate SessionFactory directly whenever we need to:
public abstract class FooHibernateDAO{
@Autowired
SessionFactory sessionFactory;
...
protected Session getCurrentSession(){
return sessionFactory.getCurrentSession();
}
}6. Maven
To add the Spring Persistence dependencies to the pom, please see the Spring with Maven example – we’ll need to define both spring-context and spring-orm.
Continuing to Hibernate 3, the Maven dependencies are simple:
<dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>3.6.10.Final</version> </dependency>
Then, to enable Hibernate to use its proxy model, we need javassist as well:
<dependency> <groupId>org.javassist</groupId> <artifactId>javassist</artifactId> <version>3.18.0-GA</version> </dependency>
We’re going to use MySQL as our DB for this tutorial, so we’ll also need:
<dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.25</version> <scope>runtime</scope> </dependency>
And finally, we will not be using the Spring datasource implementation – the DriverManagerDataSource; instead we’ll use a production ready connection pool solution – Tomcat JDBC Connection Pool:
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-dbcp</artifactId>
<version>7.0.41</version>
</dependency>7. Conclusion
In this example, we configured Hibernate 3 with Spring – both with Java and XML configuration. The implementation of this simple project can be found in the github project – this is an Eclipse based project, so it should be easy to import and run as it is.
