com.miranteinfo.seam.hibernate.HibernateAutoFlushEventListener.java Source code

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Here is the source code for com.miranteinfo.seam.hibernate.HibernateAutoFlushEventListener.java

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/*
  * Mirante Tecnologia
  * Copyright 2010, Mirante Informatica LTDA, 
  * and individual contributors as indicated by the @authors tag
  *
  * This is free software; you can redistribute it and/or modify it
  * under the terms of the GNU Lesser General Public License as
  * published by the Free Software Foundation; either version 2.1 of
  * the License, or (at your option) any later version.
  *
  * This software is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this software; if not, write to the Free
  * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
  */
package com.miranteinfo.seam.hibernate;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.FlushMode;
import org.hibernate.HibernateException;
import org.hibernate.event.AutoFlushEvent;
import org.hibernate.event.AutoFlushEventListener;
import org.hibernate.event.EventSource;

import com.miranteinfo.seam.hibernate.envers.EnversConfiguration;

/**
 * Override hibernate auto flush event listener to support our persist logic.
 * 
 * @author lucas lins
 *
 */
public class HibernateAutoFlushEventListener extends HibernateFlushEventListener implements AutoFlushEventListener {

    private static final long serialVersionUID = 1L;

    private static final Log log = LogFactory.getLog(HibernateAutoFlushEventListener.class);

    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    // constructor
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    public HibernateAutoFlushEventListener(EnversConfiguration envers) {
        super(envers);
    }

    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    // on-flushing section
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    /** Handle the given auto-flush event.
     *
     * @param event The auto-flush event to be handled.
     * @throws HibernateException
     */
    public void onAutoFlush(AutoFlushEvent event) throws HibernateException {

        final EventSource source = event.getSession();

        if (flushMightBeNeeded(source)) {

            final int oldSize = source.getActionQueue().numberOfCollectionRemovals();

            flushEverythingToExecutions(event);

            if (flushIsReallyNeeded(event, source)) {

                log.trace("Need to execute flush");

                performExecutions(source);
                postFlush(source);
                // note: performExecutions() clears all collectionXxxxtion 
                // collections (the collection actions) in the session

                if (source.getFactory().getStatistics().isStatisticsEnabled()) {
                    source.getFactory().getStatisticsImplementor().flush();
                }

            } else {

                log.trace("Dont need to execute flush");
                source.getActionQueue().clearFromFlushNeededCheck(oldSize);
            }

            event.setFlushRequired(flushIsReallyNeeded(event, source));

        }

    }

    private boolean flushIsReallyNeeded(AutoFlushEvent event, final EventSource source) {
        return source.getActionQueue().areTablesToBeUpdated(event.getQuerySpaces())
                || source.getFlushMode() == FlushMode.ALWAYS;
    }

    private boolean flushMightBeNeeded(final EventSource source) {
        return !source.getFlushMode().lessThan(FlushMode.AUTO) && source.getDontFlushFromFind() == 0
                && source.getPersistenceContext().hasNonReadOnlyEntities();
    }

}