    001    // Copyright 2011 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.jpa;
    016
    017    import java.util.Map;
    018
    019    import javax.persistence.EntityManager;
    020
    021    /**
    022     * Manages <code>EntityManager</code>s for the current thread.
    023     * An <code>EntityManager</code> is created as needed and closed at the end of each request.
    024     *
    025     * <p/>
    026     *
    027     * The implementation of this service is per-thread.
    028     *
    029     * @since 5.3
    030     */
    031    public interface EntityManagerManager
    032    {
    033        /**
    034         * Gets the active <code>EntityManager</code> for this request, creating it as necessary.
    035         *
    036         * @param persistenceUnitName the name of a persistence unit as defined in <code>persistence.xml<code>
    037         * @return EntityManager for the persistence unit,
    038         */
    039        EntityManager getEntityManager(String persistenceUnitName);
    040
    041        /**
    042         * Gets all active <code>EntityManager</code>s for this request, creating them as necessary.
    043         *
    044         * @return Map in which persistence unit names are associated with EntityManagers
    045         */
    046        Map<String, EntityManager> getEntityManagers();
    047    }