Java tutorial
/**************************************************************** * Licensed to the Apache Software Foundation (ASF) under one * * or more contributor license agreements. See the NOTICE file * * distributed with this work for additional information * * regarding copyright ownership. The ASF licenses this file * * to you under the Apache License, Version 2.0 (the * * "License"); you may not use this file except in compliance * * with the License. You may obtain a copy of the License at * * * * http://www.apache.org/licenses/LICENSE-2.0 * * * * Unless required by applicable law or agreed to in writing, * * software distributed under the License is distributed on an * * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * * KIND, either express or implied. See the License for the * * specific language governing permissions and limitations * * under the License. * ****************************************************************/ package org.apache.james.mailbox.jpa.mail; import javax.inject.Inject; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.PersistenceException; import org.apache.commons.lang.NotImplementedException; import org.apache.james.mailbox.MailboxPathLocker; import org.apache.james.mailbox.MailboxSession; import org.apache.james.mailbox.exception.MailboxException; import org.apache.james.mailbox.jpa.JPAId; import org.apache.james.mailbox.jpa.mail.model.JPAMailbox; import org.apache.james.mailbox.model.MailboxId; import org.apache.james.mailbox.store.mail.AbstractLockingModSeqProvider; import org.apache.james.mailbox.store.mail.model.Mailbox; public class JPAModSeqProvider extends AbstractLockingModSeqProvider { private final EntityManagerFactory factory; @Inject public JPAModSeqProvider(MailboxPathLocker locker, EntityManagerFactory factory) { super(locker); this.factory = factory; } @Override public long highestModSeq(MailboxSession session, Mailbox mailbox) throws MailboxException { EntityManager manager = null; try { manager = factory.createEntityManager(); manager.getTransaction().begin(); JPAId mailboxId = (JPAId) mailbox.getMailboxId(); long highest = (Long) manager.createNamedQuery("findHighestModSeq") .setParameter("idParam", mailboxId.getRawId()).getSingleResult(); manager.getTransaction().commit(); return highest; } catch (PersistenceException e) { if (manager != null && manager.getTransaction().isActive()) { manager.getTransaction().rollback(); } throw new MailboxException("Unable to get highest mod-sequence for mailbox " + mailbox, e); } finally { if (manager != null) { manager.close(); } } } @Override protected long lockedNextModSeq(MailboxSession session, Mailbox mailbox) throws MailboxException { EntityManager manager = null; try { manager = factory.createEntityManager(); manager.getTransaction().begin(); JPAId mailboxId = (JPAId) mailbox.getMailboxId(); JPAMailbox m = manager.find(JPAMailbox.class, mailboxId.getRawId()); long modSeq = m.consumeModSeq(); manager.persist(m); manager.getTransaction().commit(); return modSeq; } catch (PersistenceException e) { if (manager != null && manager.getTransaction().isActive()) { manager.getTransaction().rollback(); } throw new MailboxException("Unable to save highest mod-sequence for mailbox " + mailbox, e); } finally { if (manager != null) { manager.close(); } } } @Override public long highestModSeq(MailboxSession session, MailboxId mailboxId) throws MailboxException { throw new NotImplementedException(); } }