Should a connection obtained from a hibernate session be closed?

user_1862828 0
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Do I need to manually close a connection obtained from a hibernate session?

If I do this, will I be closing one of the connections in the connection pool?

Will hibernate automatically close the connection if I do not?

            Connection con = null;
            PreparedStatement ps = null;
            ResultSet rs = null;

            String query = "sql query";
            try {
                Session session = this.sessionFactory.getCurrentSession();
                con = session.connection();
                ps = con.prepareStatement(query);
                rs = ps.executeQuery();
                while (rs.next()) {
                    //read result set
                }
            } catch (SQLException exp) {
                log.error("Error: ", exp);
            } finally{
               if(ps != null)
                   ps.close();
               if(con != null)
                   con.close();  //Is this required?
            }
database-connection connection-pooling hibernate java
3 Answers

In general no you should not close that connection. The hibernate session may still want to use the same connection object for other tasks later in the life-cycle of the session that you are going to break by closing its connection. It is hibernate's job to manage the lifecycle of that connection object.

The exception is, as described in the javadoc, if you have ConnectionReleaseMode.AFTER_STATEMENT turned on and the JDBC provider supports that mode. Which is not often the case since you have to be in auto-commit mode for it to work.

user_3310520

Yes, you should close the connection. If you are using a connection pool, you should disconnect the session, this will not actually close it, but it will release it back to the pool.

For non-connection pools. In the javadocs it states

Note: A Connection object is automatically closed when it is garbage collected. Certain fatal errors also close a Connection object.

However, as it will be closed, it would be better to do by yourself.

user_23102890

Hibernate should release JDBC connections. By default, a JDBC connection is held until the session is explicitly closed or disconnected. For an application server JTA datasource, use after_statement to aggressively release connections after every JDBC call. For a non-JTA connection, it often makes sense to release the connection at the end of each transaction, by using after_transaction. auto will choose after_statement for the JTA and CMT transaction strategies and after_transaction for the JDBC transaction strategy.

e.g. auto (default) | on_close | after_transaction | after_statement

user_14583770
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