CODEWITHSUNDEEP
javaspringhibernate
polmarex
polmarex

Reputation: 1383

How to use two databases/datasources in Spring and Hibernate

I need to use two databases in my standalone application, one local HSQLDB and another remote MySQL. I use Spring 3.1.2, Hibernate 4.1.7. So far I managed to use only HSQLDB, this is how my DAO and configurations look like:

@Transactional
public abstract class HibernateDao<T, ID extends Serializable> implements Dao<T, ID>{

SessionFactory sessionFactoryHSQL;


public void setSessionFactoryHSQL(SessionFactory sessionFactory) {
    this.sessionFactoryHSQL = sessionFactory;
}

public ID save(T object) {
    return (ID) getCurrentSession().save(object);
}

public void persist(T object){
    getCurrentSession().persist(object);
}

public void update(T object) {
    getCurrentSession().update(object);
}

public void delete(T object) {
    getCurrentSession().delete(object);
}

public List<T> find(String query) {
    return getCurrentSession().createQuery(query).list();
}

public Session getCurrentSession(){
    return sessionFactoryHSQL.getCurrentSession();
}
}


<bean id="sessionFactoryHSQL" 
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">

    <property name="dataSource">
      <ref bean="dataSourceHSQL"/>
    </property>

    <property name="hibernateProperties">
       <props>
         <prop key="hibernate.dialect">org.hibernate.dialect.HSQLDialect</prop>
         <prop key="hibernate.show_sql">true</prop>
         <prop key="hibernate.hbm2ddl.auto">update</prop>
       </props>
    </property>

    <property name="annotatedClasses">
    <list>
        //annotated classes
    </list>
    </property>
    </bean>

<bean id="txManager" class=
    "org.springframework.orm.hibernate4.HibernateTransactionManager">
   <property name="sessionFactory" ref="sessionFactoryHSQL" />
</bean>
<tx:annotation-driven transaction-manager="txManagerHSQL" />

<bean id="configHSQL"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="location">
        <value>properties/HSQL.properties</value>
    </property>
</bean>

<bean id="dataSourceHSQL" 
         class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${jdbc.driverClassName}" />
    <property name="url" value="${jdbc.url}" />
    <property name="username" value="${jdbc.username}" />
    <property name="password" value="${jdbc.password}" />
</bean>

I created separate beans for MySQL, such as sessionFactoryMySQL, dataSourceMySQL (I'm not going to paste their implementations as they are nearly the same as for HSQL). I managed to correctly inject sessionFactoryMySQL to DAO, but I can't use both sessionFactorys at the same time, for example I can't do following:

public void persist(T object) {
    sessionFactoryHSQL.getCurrentSession().persist(object);
    sessionFactoryMySQL.getCurrentSession().persist(object);
}

As I already discovered, it has something to do with transactions, but I can't properly configure transaction manager. I have been searching for solution for a long time but examples or tutorias was either not clear or did not refer to exaclty my case.

Upvotes: 2

Views: 1377

Answers (1)

Rahul Jain
Rahul Jain

Reputation: 658

You need to create two Session Factories for both database. Check the simple step by step example : Two Datasource in Spring/Hiberate

Upvotes: 2

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