Java tutorial
/** * Copyright (C) 2012-2015 52North Initiative for Geospatial Open Source * Software GmbH * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * * If the program is linked with libraries which are licensed under one of * the following licenses, the combination of the program with the linked * library is not considered a "derivative work" of the program: * * - Apache License, version 2.0 * - Apache Software License, version 1.0 * - GNU Lesser General Public License, version 3 * - Mozilla Public License, versions 1.0, 1.1 and 2.0 * - Common Development and Distribution License (CDDL), version 1.0 * * Therefore the distribution of the program linked with libraries licensed * under the aforementioned licenses, is permitted by the copyright holders * if the distribution is compliant with both the GNU General Public * License version 2 and the aforementioned licenses. * * 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. */ package org.n52.sos.ds.hibernate.dao; import java.sql.Timestamp; import org.hibernate.Criteria; import org.hibernate.Session; import org.hibernate.criterion.Order; import org.hibernate.criterion.Projection; import org.hibernate.criterion.Projections; import org.hibernate.criterion.Restrictions; import org.n52.sos.ds.hibernate.entities.AbstractObservation; import org.n52.sos.ds.hibernate.entities.values.AbstractValue; import org.n52.sos.ds.hibernate.util.SpatialRestrictions; import org.n52.sos.exception.CodedException; import org.n52.sos.ogc.filter.TemporalFilter; import org.n52.sos.ogc.ows.OwsExceptionReport; import org.n52.sos.ogc.sos.SosConstants.SosIndeterminateTime; import org.n52.sos.request.GetObservationRequest; import org.n52.sos.util.GeometryHandler; /** * Abstract DAO class for querying {@link AbstractValue} * * @author Carsten Hollmann <c.hollmann@52north.org> * @since 4.1.0 * */ public abstract class AbstractValueDAO extends TimeCreator { /** * Check if a Spatial Filtering Profile filter is requested and add to * criteria * * @param c * Criteria to add crtierion * @param request * GetObservation request * @param session * Hiberante Session * @throws OwsExceptionReport * If Spatial Filteirng Profile is not supported or an error * occurs. */ protected void checkAndAddSpatialFilteringProfileCriterion(Criteria c, GetObservationRequest request, Session session) throws OwsExceptionReport { if (request.hasSpatialFilteringProfileSpatialFilter()) { c.add(SpatialRestrictions.filter(AbstractObservation.SAMPLING_GEOMETRY, request.getSpatialFilter().getOperator(), GeometryHandler.getInstance().switchCoordinateAxisFromToDatasourceIfNeeded( request.getSpatialFilter().getGeometry()))); } } /** * Add an indeterminate time restriction to a criteria. This allows for * multiple results if more than one observation has the extrema time (max * for latest, min for first). Note: use this method *after* adding all * other applicable restrictions so that they will apply to the min/max * observation time determination. * * @param c * Criteria to add the restriction to * @param sosIndeterminateTime * Indeterminate time restriction to add * @return Modified criteria */ protected Criteria addIndeterminateTimeRestriction(Criteria c, SosIndeterminateTime sosIndeterminateTime) { // get extrema indeterminate time c.setProjection(getIndeterminateTimeExtremaProjection(sosIndeterminateTime)); Timestamp indeterminateExtremaTime = (Timestamp) c.uniqueResult(); // reset criteria // see http://stackoverflow.com/a/1472958/193435 c.setProjection(null); c.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY); // get observations with exactly the extrema time c.add(Restrictions.eq(getIndeterminateTimeFilterProperty(sosIndeterminateTime), indeterminateExtremaTime)); // not really necessary to return the Criteria object, but useful if we // want to chain return c; } /** * Get projection for {@link SosIndeterminateTime} value * * @param indetTime * Value to get projection for * @return Projection to use to determine indeterminate time extrema */ protected Projection getIndeterminateTimeExtremaProjection(final SosIndeterminateTime indetTime) { if (indetTime.equals(SosIndeterminateTime.first)) { return Projections.min(AbstractValue.PHENOMENON_TIME_START); } else if (indetTime.equals(SosIndeterminateTime.latest)) { return Projections.max(AbstractValue.PHENOMENON_TIME_END); } return null; } /** * Get the AbstractValue property to filter on for an * {@link SosIndeterminateTime} * * @param indetTime * Value to get property for * @return String property to filter on */ protected String getIndeterminateTimeFilterProperty(final SosIndeterminateTime indetTime) { if (indetTime.equals(SosIndeterminateTime.first)) { return AbstractValue.PHENOMENON_TIME_START; } else if (indetTime.equals(SosIndeterminateTime.latest)) { return AbstractValue.PHENOMENON_TIME_END; } return null; } /** * Add chunk information to {@link Criteria} * * @param c * {@link Criteria} to add information * @param chunkSize * Chunk size * @param currentRow * Start row * @param request */ protected void addChunkValuesToCriteria(Criteria c, int chunkSize, int currentRow, GetObservationRequest request) { c.addOrder(Order.asc(getOrderColumn(request))); if (chunkSize > 0) { c.setMaxResults(chunkSize).setFirstResult(currentRow); } } private String getOrderColumn(GetObservationRequest request) { if (request.isSetTemporalFilter()) { TemporalFilter filter = request.getTemporalFilters().iterator().next(); if (filter.getValueReference().contains(AbstractValue.RESULT_TIME)) { return AbstractValue.RESULT_TIME; } } return AbstractValue.PHENOMENON_TIME_START; } protected abstract void addSpecificRestrictions(Criteria c, GetObservationRequest request) throws CodedException; }