GPPreparerDeleteHandler.java

/**
 *
 *    geo-platform
 *    Rich webgis framework
 *    http://geo-platform.org
 *   ====================================================================
 *
 *   Copyright (C) 2008-2017 geoSDI Group (CNR IMAA - Potenza - ITALY).
 *
 *   This program is free software: you can redistribute it and/or modify it
 *   under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version. This program 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 General Public License
 *   for more details. You should have received a copy of the GNU General
 *   Public License along with this program. If not, see http://www.gnu.org/licenses/
 *
 *   ====================================================================
 *
 *   Linking this library statically or dynamically with other modules is
 *   making a combined work based on this library. Thus, the terms and
 *   conditions of the GNU General Public License cover the whole combination.
 *
 *   As a special exception, the copyright holders of this library give you permission
 *   to link this library with independent modules to produce an executable, regardless
 *   of the license terms of these independent modules, and to copy and distribute
 *   the resulting executable under terms of your choice, provided that you also meet,
 *   for each linked independent module, the terms and conditions of the license of
 *   that module. An independent module is a module which is not derived from or
 *   based on this library. If you modify this library, you may extend this exception
 *   to your version of the library, but you are not obligated to do so. If you do not
 *   wish to do so, delete this exception statement from your version.
 */
package org.geosdi.geoplatform.experimental.el.search.delete.responsibility;

import com.google.common.base.Preconditions;
import org.elasticsearch.action.search.SearchRequestBuilder;
import org.geosdi.geoplatform.experimental.el.dao.ElasticSearchDAO;
import org.geosdi.geoplatform.experimental.el.search.delete.DeleteByPage;
import org.geosdi.geoplatform.experimental.el.search.delete.DeleteByPage.DeleteByPageSearchDecorator;
import org.geosdi.geoplatform.experimental.el.search.delete.DeleteByPage.IDeleteByPageResult;

import static org.geosdi.geoplatform.experimental.el.search.delete.responsibility.GPElasticSearchDeleteHandler.GPElasticSearchDeleteHandlerType.PREPARER_DELETE_TYPE;

/**
 * @author Giuseppe La Scaleia - CNR IMAA geoSDI Group
 * @email giuseppe.lascaleia@geosdi.org
 */
class GPPreparerDeleteHandler extends GPAbstractDeleteHandler<ElasticSearchDAO> {

    public GPPreparerDeleteHandler() {
        super.setSuccessor(new GPSingleDeleteHandler());
    }

    /**
     * @param page
     * @param searchDAO
     * @return {@link Result}
     * @throws Exception
     */
    @Override
    public <Result extends IDeleteByPageResult, Page extends DeleteByPage> Result delete(Page page,
            ElasticSearchDAO searchDAO) throws Exception {
        return (canDelete(page) ? internalDelete(page, searchDAO) : super.forwardDelete(page, searchDAO));
    }

    /**
     * @param page
     * @param searchDAO
     * @return {@link Result}
     * @throws Exception
     */
    @Override
    protected final <Result extends IDeleteByPageResult, Page extends DeleteByPage> Result internalDelete(Page page,
            ElasticSearchDAO searchDAO) throws Exception {
        Preconditions.checkNotNull(page, "Parameter Page must not be null.");
        Preconditions.checkNotNull(searchDAO, "Parameter SearchDAO must not be null.");

        SearchRequestBuilder builder = page.buildPage(searchDAO.client()
                .prepareSearch(searchDAO.getIndexName()).setTypes(searchDAO.getIndexType()));
        Long totalElementsToDelete = builder.execute().get().getHits().getTotalHits();
        return super.forwardDelete(new DeleteByPageSearchDecorator(page.getPage(), totalElementsToDelete),
                searchDAO);
    }

    /**
     * @param page
     * @return {@link Boolean}
     */
    @Override
    protected <Page extends DeleteByPage> Boolean canDelete(Page page) {
        return ((page.getSize() != null) && (page.getSize() == 0));
    }

    /**
     * @return {@link TYPE}
     */
    @Override
    public <TYPE extends IGPElasticSearchDeleteHandlerType> TYPE getDeleteType() {
        return (TYPE) PREPARER_DELETE_TYPE;
    }
}