org.neo4j.gis.spatial.AbstractGeometryEncoder.java Source code

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Here is the source code for org.neo4j.gis.spatial.AbstractGeometryEncoder.java

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/**
 * Copyright (c) 2002-2011 "Neo Technology,"
 * Network Engine for Objects in Lund AB [http://neotechnology.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.gis.spatial;

import org.apache.commons.lang.ArrayUtils;
import org.neo4j.graphdb.Node;
import org.neo4j.graphdb.PropertyContainer;

import com.vividsolutions.jts.geom.Envelope;
import com.vividsolutions.jts.geom.Geometry;

/**
 * @author Davide Savazzi
 */
public abstract class AbstractGeometryEncoder implements GeometryEncoder, Constants {

    // Public methods

    public void init(Layer layer) {
        this.layer = layer;
    }

    public void encodeEnvelope(Envelope mbb, PropertyContainer container) {
        container.setProperty(PROP_BBOX,
                new double[] { mbb.getMinX(), mbb.getMinY(), mbb.getMaxX(), mbb.getMaxY() });
    }

    public void encodeGeometry(Geometry geometry, PropertyContainer container) {
        container.setProperty(PROP_TYPE, encodeGeometryType(geometry.getGeometryType()));
        container.setProperty(PROP_SRID, geometry.getSRID());
        encodeEnvelope(geometry.getEnvelopeInternal(), container);

        encodeGeometryShape(geometry, container);
    }

    public Envelope decodeEnvelope(PropertyContainer container) {
        double[] bbox = new double[] { 0, 0, 0, 0, };
        Object bboxProp = container.getProperty(PROP_BBOX);
        if (bboxProp instanceof Double[]) {
            bbox = ArrayUtils.toPrimitive((Double[]) bboxProp);
        } else if (bboxProp instanceof double[]) {
            bbox = (double[]) bboxProp;
        }
        // Envelope parameters: xmin, xmax, ymin, ymax
        return new Envelope(bbox[0], bbox[2], bbox[1], bbox[3]);
    }

    // Protected methods

    protected abstract void encodeGeometryShape(Geometry geometry, PropertyContainer container);

    protected Integer encodeGeometryType(String jtsGeometryType) {
        // TODO: Consider alternatives for specifying type, like relationship to
        // type category
        // objects (or similar indexing structure)
        if ("Point".equals(jtsGeometryType)) {
            return GTYPE_POINT;
        } else if ("MultiPoint".equals(jtsGeometryType)) {
            return GTYPE_MULTIPOINT;
        } else if ("LineString".equals(jtsGeometryType)) {
            return GTYPE_LINESTRING;
        } else if ("MultiLineString".equals(jtsGeometryType)) {
            return GTYPE_MULTILINESTRING;
        } else if ("Polygon".equals(jtsGeometryType)) {
            return GTYPE_POLYGON;
        } else if ("MultiPolygon".equals(jtsGeometryType)) {
            return GTYPE_MULTIPOLYGON;
        } else {
            throw new IllegalArgumentException("unknown type:" + jtsGeometryType);
        }
    }

    /**
     * This method wraps the hasProperty(String) method on the geometry node.
     * This means the default way of storing attributes is simply as properties
     * of the geometry node. This behaviour can be changed by other domain
     * models with different encodings.
     * 
     * @param geomNode
     * @param attribute
     *            to test
     * @return
     */
    public boolean hasAttribute(Node geomNode, String name) {
        return geomNode.hasProperty(name);
    }

    /**
     * This method wraps the getProperty(String,null) method on the geometry
     * node. This means the default way of storing attributes is simply as
     * properties of the geometry node. This behaviour can be changed by other
     * domain models with different encodings. If the property does not exist,
     * the method returns null.
     * 
     * @param geomNode
     * @param attribute
     *            to test
     * @return attribute, or null
     */
    public Object getAttribute(Node geomNode, String name) {
        return geomNode.getProperty(name, null);
    }

    // Attributes

    protected Layer layer;
}