corner.orm.gae.impl.EntityManagerSourceImpl.java Source code

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Here is the source code for corner.orm.gae.impl.EntityManagerSourceImpl.java

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/* 
 * Copyright 2009 The Corner Team.
 * 
 * Licensed 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 corner.orm.gae.impl;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;

import org.apache.tapestry5.SymbolConstants;
import org.apache.tapestry5.ioc.annotations.Inject;
import org.apache.tapestry5.ioc.annotations.Symbol;
import org.apache.tapestry5.ioc.services.ThreadCleanupListener;
import org.slf4j.Logger;
import org.springframework.orm.jpa.EntityManagerFactoryUtils;
import org.springframework.orm.jpa.EntityManagerHolder;
import org.springframework.transaction.support.TransactionSynchronizationManager;

import com.google.apphosting.api.ApiProxy;
import com.google.apphosting.api.ApiProxy.Delegate;

import corner.orm.gae.EntityManagerSource;

/**
 * entity manager source implemention
 * 
 * @author <a href="mailto:jun.tsai@gmail.com">Jun Tsai</a>
 * @version $Revision$
 * @since 0.1
 */
public class EntityManagerSourceImpl implements EntityManagerSource, ThreadCleanupListener {
    private boolean participate = false;
    private EntityManagerFactory entityManagerFactory;
    private Logger logger;

    public EntityManagerSourceImpl(@Inject @Symbol(SymbolConstants.PRODUCTION_MODE) boolean product,
            EntityManagerFactory entityManagerFactory, Logger logger, Delegate delegate) {
        this.entityManagerFactory = entityManagerFactory;
        this.logger = logger;
        if (!product) {
            ApiProxy.setEnvironmentForCurrentThread(new TestEnvironment());
            ApiProxy.setDelegate(delegate);
        }

        if (TransactionSynchronizationManager.hasResource(entityManagerFactory)) {
            // Do not modify the Session: just set the participate flag.
            participate = true;
        } else {
            logger.debug("Opening single entity manager  in EntityManagerSourceImpl");
            EntityManager em = entityManagerFactory.createEntityManager();
            TransactionSynchronizationManager.bindResource(entityManagerFactory, new EntityManagerHolder(em));
        }

    }

    /**
     * @see lichen.common.services.jpa.EntityManagerSource#getEntityManager()
     */
    @Override
    public EntityManager getEntityManager() {
        EntityManagerHolder emHolder = (EntityManagerHolder) TransactionSynchronizationManager
                .getResource(entityManagerFactory);
        return emHolder.getEntityManager();
    }

    @Override
    public void threadDidCleanup() {
        if (!participate) {
            EntityManagerHolder emHolder = (EntityManagerHolder) TransactionSynchronizationManager
                    .unbindResource(entityManagerFactory);
            logger.debug("Closing JPA EntityManager in EntityManagerSourceImpl");
            EntityManagerFactoryUtils.closeEntityManager(emHolder.getEntityManager());
        }
    }

}