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
015package org.apache.tapestry5.hibernate;
016
017import 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 */
031public 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}