001    /****************************************************************
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005     * regarding copyright ownership.  The ASF licenses this file   *
006     * to you under the Apache License, Version 2.0 (the            *
007     * "License"); you may not use this file except in compliance   *
008     * with the License.  You may obtain a copy of the License at   *
009     *                                                              *
010     *   http://www.apache.org/licenses/LICENSE-2.0                 *
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014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
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017     * under the License.                                           *
018     ****************************************************************/
019    package org.apache.james.mailbox.jpa.mail;
020    
021    import javax.persistence.EntityManager;
022    import javax.persistence.EntityManagerFactory;
023    import javax.persistence.PersistenceException;
024    
025    import org.apache.james.mailbox.MailboxPathLocker;
026    import org.apache.james.mailbox.MailboxSession;
027    import org.apache.james.mailbox.exception.MailboxException;
028    import org.apache.james.mailbox.jpa.mail.model.JPAMailbox;
029    import org.apache.james.mailbox.store.mail.AbstractLockingUidProvider;
030    import org.apache.james.mailbox.store.mail.model.Mailbox;
031    
032    public class JPAUidProvider extends AbstractLockingUidProvider<Long>{
033    
034        private EntityManagerFactory factory;
035    
036        public JPAUidProvider(MailboxPathLocker locker, EntityManagerFactory factory) {
037            super(locker);
038            this.factory = factory;
039        }
040        
041        
042        @Override
043        public long lastUid(MailboxSession session, Mailbox<Long> mailbox) throws MailboxException {
044            EntityManager manager = null;
045            try {
046                manager = factory.createEntityManager();
047                manager.getTransaction().begin();
048                long uid = (Long) manager.createNamedQuery("findLastUid").setParameter("idParam", mailbox.getMailboxId()).getSingleResult();
049                manager.getTransaction().commit();
050                return uid;
051            } catch (PersistenceException e) {
052                if (manager != null && manager.getTransaction().isActive()) {
053                    manager.getTransaction().rollback();
054                }
055                throw new MailboxException("Unable to get last uid for mailbox " + mailbox, e);
056            } finally {
057                if (manager != null) {
058                    manager.close();
059                }
060            }
061        }
062    
063        @Override
064        protected long lockedNextUid(MailboxSession session, Mailbox<Long> mailbox) throws MailboxException {
065            EntityManager manager = null;
066            try {
067                manager = factory.createEntityManager();
068                manager.getTransaction().begin();
069                JPAMailbox m = manager.find(JPAMailbox.class, mailbox.getMailboxId());
070                long uid = m.consumeUid();
071                manager.persist(m);
072                manager.getTransaction().commit();
073                return uid;
074            } catch (PersistenceException e) {
075                if (manager != null && manager.getTransaction().isActive()) {
076                    manager.getTransaction().rollback();
077                }
078                throw new MailboxException("Unable to save next uid for mailbox " + mailbox, e);
079            } finally {
080                if (manager != null) {
081                    manager.close();
082                }
083            }
084        }
085    
086    }