Spring Hibernate - Could not obtain transaction-synchronized Session for current thread

Question

You must enable the transaction support (<tx:annotation-driven> or @EnableTransactionManagement) and declare the transactionManager and it should work through the SessionFactory.

You must add @Transactional into your @Repository

With @Transactional in your @Repository Spring is able to apply transactional support into your repository.

Your Student class has no the @javax.persistence.* annotations how @Entity, I am assuming the Mapping Configuration for that class has been defined through XML.

I have had the same issue, but in a class that was not a part of the service layer. In my case, the transaction manager was simply obtained from the context by the getBean() method, and the class belonged to the view layer - my project utilizes OpenSessionInView technique.

The sessionFactory.getCurrentSession() method, has been causing the same exception as the author's. The solution for me was rather simple.

Session session;

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

If the getCurrentSession() method fails, the openSession() should do the trick.

Add the annotation @Transactional of spring in the class service

In your xyz.DAOImpl.java

Do the following steps:

//Step-1: Set session factory

@Resource(name="sessionFactory")
private SessionFactory sessionFactory;

public void setSessionFactory(SessionFactory sf)
{
    this.sessionFactory = sf;
}

---

//Step-2: Try to get the current session, and catch the HibernateException exception.

---

//Step-3: If there are any HibernateException exception, then true to get openSession.

try 
{
    //Step-2: Implementation
    session = sessionFactory.getCurrentSession();
} 
catch (HibernateException e) 
{
    //Step-3: Implementation
    session = sessionFactory.openSession();
}

I added these configuration in web.xml and it works well for me!

<filter>
    <filter-name>OpenSessionInViewFilter</filter-name>
    <filter-class>org.springframework.orm.hibernate5.support.OpenSessionInViewFilter</filter-class>
    <init-param>
        <param-name>sessionFactoryBeanName</param-name>
        <param-value>sessionFactory</param-value>
    </init-param>
    <init-param>
        <param-name>flushMode</param-name>
        <param-value>AUTO</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>OpenSessionInViewFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

Additionally, the most ranked answer give me clues to prevent application from panic at the first run.

You need to allow transaction to your DAO method. Add,

@Transactional(readOnly = true, propagation=Propagation.NOT_SUPPORTED)

over your dao methods. And @Transactional should be from the package:

org.springframework.transaction.annotation.Transactional

I had this error too because in the file where I used @Transactional annotation, I was importing the wrong class

import javax.transaction.Transactional; 

Instead of javax, use

import org.springframework.transaction.annotation.Transactional;