session.connection() deprecated on Hibernate?

Question

We need to be able to get the associated java.sql.Connection of a hibernate session. No other connection will work, as this connection may be associated with a running transaction.

If session.connection() is now deprecated, how am I supposed to do that?

Answer 1

You now have to use the Work API:

session.doWork(connection -> doSomething(connection)); 

Or, in Java < 8 :

session.doWork(
    new Work() {
        public void execute(Connection connection) throws SQLException 
        { 
            doSomething(connection); 
        }
    }
);

Answer 2

If session.connect() is now deprecated, how am I supposed to do that?

You have to use Session#doWork(Work) and the Work API, as mentioned in the Javadoc:

connection()
     Deprecated. (scheduled for removal in 4.x). Replacement depends on need; for doing direct JDBC stuff use doWork(org.hibernate.jdbc.Work); for opening a 'temporary Session' use (TBD).

You have some time before Hibernate 4.x but, well, using a deprecated API somehow looks like this:

:)

Update: According to RE: [hibernate-dev] Connection proxying on the hibernate-dev list, it seems that the initial intention of the deprecation was to discourage the use of Session#connection() because it was/is considered as a "bad" API, but it was supposed to stay at that time. I guess they changed their mind...

Answer 3

Try This

((SessionImpl)getSession()).connection()

Actuly getSession returns Session Interface type, you should see what is the original class for the session, type cast to the original class then get the connection.

GOOD LUCK!

Answer 4

Here is a way to do it in Hibernate 4.3, and it is not deprecated:

  Session session = entityManager.unwrap(Session.class);
  SessionImplementor sessionImplementor = (SessionImplementor) session;
  Connection conn = sessionImplementor.getJdbcConnectionAccess().obtainConnection();

Answer 5

This is what I use and works for me. Downcast the Session object into a SessionImpl and get the connection object easily:

SessionImpl sessionImpl = (SessionImpl) session;
Connection conn = sessionImpl.connection();

where session is the name of your Hibernate session object.

Answer 6

There's another option with still a lot of casts involved, but at least it doesn't need reflection, which will give you back compile time checking:

public Connection getConnection(final EntityManager em) {
  HibernateEntityManager hem = (HibernateEntityManager) em;
  SessionImplementor sim = (SessionImplementor) hem.getSession();
  return sim.connection();
}

You could of course make that even "prettier" with a few instanceof checks, but the version above works for me.

Answer 7

I found this article

package com.varasofttech.client;

import java.sql.Connection;
import java.sql.SQLException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.engine.jdbc.connections.spi.ConnectionProvider;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.internal.SessionImpl;
import org.hibernate.jdbc.ReturningWork;
import org.hibernate.jdbc.Work;

import com.varasofttech.util.HibernateUtil;

public class Application {

public static void main(String[] args) {

    // Different ways to get the Connection object using Session

    SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
    Session session = sessionFactory.openSession();

    // Way1 - using doWork method
    session.doWork(new Work() {
        @Override
        public void execute(Connection connection) throws SQLException {
            // do your work using connection
        }

    });

    // Way2 - using doReturningWork method
    Connection connection = session.doReturningWork(new ReturningWork<Connection>() {
        @Override
        public Connection execute(Connection conn) throws SQLException {
            return conn;
        }
    });

    // Way3 - using Session Impl
    SessionImpl sessionImpl = (SessionImpl) session;
    connection = sessionImpl.connection();
    // do your work using connection

    // Way4 - using connection provider
    SessionFactoryImplementor sessionFactoryImplementation = (SessionFactoryImplementor) session.getSessionFactory();
    ConnectionProvider connectionProvider = sessionFactoryImplementation.getConnectionProvider();
    try {
        connection = connectionProvider.getConnection();
        // do your work using connection
    } catch (SQLException e) {
        e.printStackTrace();
    }
}
}

It helped me.

Answer 8

connection() was just deprecated on the interface. It is still available on SessionImpl. You can do what Spring does and just call that one.

Here is the code from HibernateJpaDialect in Spring 3.1.1

public Connection getConnection() {
        try {
            if (connectionMethod == null) {
                // reflective lookup to bridge between Hibernate 3.x and 4.x
                connectionMethod = this.session.getClass().getMethod("connection");
            }
            return (Connection) ReflectionUtils.invokeMethod(connectionMethod, this.session);
        }
        catch (NoSuchMethodException ex) {
            throw new IllegalStateException("Cannot find connection() method on Hibernate session", ex);
        }
    }

Answer 9

With Hibernate >= 5.0 you can get the Connection like this:

Connection c = sessionFactory.
getSessionFactoryOptions().getServiceRegistry().
getService(ConnectionProvider.class).getConnection();

Answer 10

For hibenate 4.3 try this:

public static Connection getConnection() {
        EntityManager em = <code to create em>;
        Session ses = (Session) em.getDelegate();
        SessionFactoryImpl sessionFactory = (SessionFactoryImpl) ses.getSessionFactory();
        try{
            connection = sessionFactory.getConnectionProvider().getConnection();
        }catch(SQLException e){
            ErrorMsgDialog.getInstance().setException(e);
        }
        return connection;
    }

Answer 11

Try this:

public Connection getJavaSqlConnectionFromHibernateSession() {

    Session session = this.getSession();
    SessionFactoryImplementor sessionFactoryImplementor = null;
    ConnectionProvider connectionProvider = null;
    java.sql.Connection connection = null;
    try {
        sessionFactoryImplementor = (SessionFactoryImplementor) session.getSessionFactory();
        connectionProvider = (ConnectionProvider) sessionFactoryImplementor.getConnectionProvider().getConnection();
        connection = connectionProvider.getConnection();
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return connection;
}

Answer 12

    Connection conn = null;
    PreparedStatement preparedStatement = null;
    try {
        Session session = (org.hibernate.Session) em.getDelegate();
        SessionFactoryImplementor sfi = (SessionFactoryImplementor) session.getSessionFactory();
        ConnectionProvider cp = sfi.getConnectionProvider();
        conn = cp.getConnection();
        preparedStatement = conn.prepareStatement("Select id, name from Custumer");
        ResultSet rs = preparedStatement.executeQuery();
        while (rs.next()) {
            System.out.print(rs.getInt(1));
            System.out.println(rs.getString(2));
        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        if (preparedStatement != null) {
            preparedStatement.close();
        }
        if (conn != null) {
            conn.close();
        }
    }

Answer 13

Here is a Java 8 method to return the Connection used by an EntityManager without actually doing anything with it yet:

private Connection getConnection(EntityManager em) throws SQLException {
    AtomicReference<Connection> atomicReference = new AtomicReference<Connection>();
    final Session session = em.unwrap(Session.class);
    session.doWork(connection -> atomicReference.set(connection));
    return atomicReference.get();
}

Answer 14

If you need a return value from inside the lambda, don't overlook doReturningWork()

try {
  return session.doReturningWork(connection -> {
    try (CallableStatement cs = connection.prepareCall(...)) {
      cs.doSomethingPseudoMethod();
      cs.executeUpdate();
      return cs;
    }
  });
} catch (SQLException sqlException) {
  ...
}