org.wallride.service.SystemService.java Source code

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Here is the source code for org.wallride.service.SystemService.java

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/*
 * Copyright 2014 Tagbangers, Inc.
 *
 * 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.wallride.service;

import org.hibernate.*;
import org.hibernate.search.FullTextSession;
import org.hibernate.search.Search;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

@Service
public class SystemService {

    private static final int BATCH_SIZE = 100;

    private static Logger logger = LoggerFactory.getLogger(SystemService.class);

    @PersistenceContext
    private EntityManager entityManager;

    @Async
    @Transactional(propagation = Propagation.SUPPORTS)
    public void reIndex() throws Exception {
        logger.info("Re-Index started");

        FullTextSession fullTextSession = Search.getFullTextSession((entityManager.unwrap(Session.class)));

        fullTextSession.setFlushMode(FlushMode.MANUAL);
        fullTextSession.setCacheMode(CacheMode.IGNORE);

        for (Class persistentClass : fullTextSession.getSearchFactory().getIndexedTypes()) {
            Transaction transaction = fullTextSession.beginTransaction();

            // Scrollable results will avoid loading too many objects in memory
            ScrollableResults results = fullTextSession.createCriteria(persistentClass).setFetchSize(BATCH_SIZE)
                    .scroll(ScrollMode.FORWARD_ONLY);
            int index = 0;
            while (results.next()) {
                index++;
                fullTextSession.index(results.get(0)); //index each element
                if (index % BATCH_SIZE == 0) {
                    fullTextSession.flushToIndexes(); //apply changes to indexes
                    fullTextSession.clear(); //free memory since the queue is processed
                }
            }
            transaction.commit();
        }
        logger.info("Re-Index finished");
    }
}