"Could not obtain transaction-synchronized Session for current thread" error in Spring transaction management

Question

I am working on migrating an application from Spring 3.2 to Spring 5. The application uses AWS RDS with a primary database as primary or master datasource and a replica database as read-only datasource. The application creates one session factory ( primarySessionFacotry) instance for the primary data source and another one ( readOnlySessionFactory) for the read-only data source so that the same DAO can be used for both datasource by wiring each session factories.

appContext-hibernate.xml

<bean id="primaryDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
    <property name="driverClass">
        <value>com.mysql.jdbc.Driver</value>
    </property>
    <property name="jdbcUrl">
        <value>${database.jdbcurl}</value>
    </property>
    <property name="user">
        <value>${database.dbuser}</value>
    </property>
    <property name="password">
        <value>${database.dbpassword}</value>
    </property>

</bean>

<bean id="primarySessionFactory"
      class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
    <property name="dataSource" ref="primaryDataSource"/>
    <property name="mappingResources" ref="hbmFileLocations">
    </property>
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
            <prop key="hibernate.show_sql">${hibernate.showSQL}</prop>
            <prop key="hibernate.format_sql">${hibernate.formatSQL}</prop>
        </props>
    </property>
</bean>

<util:list id="hbmFileLocations" value-type="java.lang.String">
    <value>com/xxxx/yyyyy/persistence/mappings/users.hbm.xml</value>
</util:list>

<bean id="primaryTransactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager">
    <property name="sessionFactory" ref="primarySessionFactory">
    </property>
</bean>

<tx:annotation-driven transaction-manager="primaryTransactionManager"/>

appContext-hibernate-ro.xml

<bean id="readOnlyDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
    <property name="driverClass">
        <value>com.mysql.jdbc.Driver</value>
    </property>
    <property name="jdbcUrl">
        <value>${database.readonly.jdbcurl}</value>
    </property>
    <property name="user">
        <value>${database.readonly.dbuser}</value>
    </property>
    <property name="password">
        <value>${database.readonly.dbpassword}</value>
    </property>
    
</bean>

<bean id="readOnlySessionFactory"
      class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
    <property name="dataSource" ref="readOnlyDataSource"/>
    <property name="mappingResources" ref="hbmFileLocations">
    </property>
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
            <prop key="hibernate.show_sql">${hibernate.readonly.showSQL}</prop>
            <prop key="hibernate.format_sql">${hibernate.readonly.formatSQL}</prop>
        </props>
    </property>

</bean>

<bean id="readOnlyTransactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager">
    <property name="sessionFactory" ref="readOnlySessionFactory"/>
</bean>

<tx:annotation-driven transaction-manager="readOnlyTransactionManager"/>

DAOs are instantiated like this

<bean id="userDao" class="xxxxx.persistence.UserDao">
    <property name="sessionFactory" ref="primarySessionFactory"/>
</bean>
<bean id="readOnlyUserDao" class="xxxxx.persistence.UserDao">
    <property name="sessionFactory" ref="readOnlySessionFactory"/>
</bean>

This UserDao has a method like below

@Transactional
public List<User> getItems()
{
    return sessionFactory.getCurrentSession().createQuery("from User user where isDeleted=false").list();
}

We are getting below exception when using the UserDao.getItems() method with readOnlyUserDao intance.

org.hibernate.HibernateException: Could not obtain transaction-synchronized Session for current thread
at org.springframework.orm.hibernate5.SpringSessionContext.currentSession(SpringSessionContext.java:143)
at org.hibernate.internal.SessionFactoryImpl.getCurrentSession(SessionFactoryImpl.java:497)

Please note that the same code is perfectly working with Spring ( spring-orm and spring-tx 3.2)

Please assist to resolve this.

Answer 1

I had the same issue and followed the step mentioned here and which works fine for my case. Spring Hibernate - Could not obtain transaction-synchronized Session for current thread

Session session;
try {
    session = sessionFactory.getCurrentSession();
} catch (HibernateException e) {
    session = sessionFactory.openSession();
}
return session;