    001    // Copyright 2007, 2008 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    //     http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.hibernate;
    016
    017    import org.hibernate.Session;
    018
    019    /**
    020     * Manages the Hibernate session for the current thread. This includes creating the session as needed, allowing the
    021     * session to checkpoint (commit the current transaction and continue) and commit the transaction automatically at the
    022     * end of the request.
    023     * <p/>
    024     * Remember that in Tapestry, action requests and render requests are entirely separate, and you will see a separate
    025     * request and a separate transaction for each. Care should be taken to ensure that entity objects that are retained (in
    026     * the session, as persistent field values) between requests are handled correctly (they tend to become detached
    027     * instances).
    028     * <p/>
    029     * This implementation of this service is per-thread.
    030     */
    031    public interface HibernateSessionManager
    032    {
    033        /**
    034         * Gets the active session for this request, creating it as necessary. When the session is first created, a
    035         * transaction is started.
    036         *
    037         * @return the request's session
    038         * @see HibernateSessionSource
    039         */
    040        Session getSession();
    041
    042        /**
    043         * Commits the current transaction (which will cause a flush of data to the database), then starts a new transaction
    044         * to replace it.
    045         */
    046        void commit();
    047
    048        /**
    049         * Aborts the current transaction, and starts a new transaction to replace it.
    050         */
    051        void abort();
    052    }