org.grails.datastore.mapping.transactions.support.SpringSessionSynchronization.java Source code

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Here is the source code for org.grails.datastore.mapping.transactions.support.SpringSessionSynchronization.java

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/* Copyright (C) 2010 SpringSource
 *
 * 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 org.grails.datastore.mapping.transactions.support;

import org.springframework.dao.DataAccessException;
import org.grails.datastore.mapping.core.Datastore;
import org.grails.datastore.mapping.core.DatastoreUtils;
import org.grails.datastore.mapping.core.Session;
import org.grails.datastore.mapping.transactions.SessionHolder;
import org.springframework.transaction.support.TransactionSynchronization;
import org.springframework.transaction.support.TransactionSynchronizationManager;

/**
 * An instance of {@link org.springframework.transaction.support.TransactionSynchronization}
 * for the Datastore abstraction. Based on similar work for Hibernate
 *
 * @author Juergen Hoeller
 * @author Graeme Rocher
 */
public class SpringSessionSynchronization implements TransactionSynchronization {

    private final SessionHolder sessionHolder;
    private final Datastore datastore;
    private final boolean newSession;
    private boolean holderActive = true;

    public SpringSessionSynchronization(SessionHolder sessionHolder, Datastore datastore, boolean newSession) {
        this.sessionHolder = sessionHolder;
        this.datastore = datastore;
        this.newSession = newSession;
    }

    /**
     * Check whether there is a Hibernate Session for the current JTA
     * transaction. Else, fall back to the default thread-bound Session.
     */
    private Session getCurrentSession() {
        return sessionHolder.getSession();
    }

    public void suspend() {
        if (holderActive) {
            TransactionSynchronizationManager.unbindResource(datastore);
            getCurrentSession().disconnect();
        }
    }

    public void resume() {
        if (holderActive) {
            TransactionSynchronizationManager.bindResource(datastore, sessionHolder);
        }
    }

    public void flush() {
        // do nothing
    }

    public void beforeCommit(boolean readOnly) throws DataAccessException {
        // do nothing
    }

    public void beforeCompletion() {
        if (newSession) {
            // Default behavior: unbind and close the thread-bound Hibernate Session.
            TransactionSynchronizationManager.unbindResource(datastore);
            holderActive = false;
        }
    }

    public void afterCommit() {
    }

    public void afterCompletion(int status) {
        // No Hibernate TransactionManagerLookup: apply afterTransactionCompletion callback.
        // Always perform explicit afterTransactionCompletion callback for pre-bound Session,
        // even with Hibernate TransactionManagerLookup (which only applies to new Sessions).
        Session session = sessionHolder.getSession();
        // Close the Hibernate Session here if necessary
        // (closed in beforeCompletion in case of TransactionManagerLookup).
        if (newSession) {
            DatastoreUtils.closeSessionOrRegisterDeferredClose(session, datastore);
        } else {
            session.disconnect();
        }
        if (sessionHolder.doesNotHoldNonDefaultSession()) {
            sessionHolder.setSynchronizedWithTransaction(false);
        }
    }
}