org.opengis.cite.cat30.util.SpatialUtils Maven / Gradle / Ivy

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package org.opengis.cite.cat30.util;

import java.util.logging.Level;
import java.util.logging.Logger;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.sis.geometry.GeneralEnvelope;
import org.apache.sis.referencing.CommonCRS;
import org.opengis.cite.cat30.Namespaces;
import org.opengis.geometry.Envelope;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;

/**
 * Utility methods pertaining to geographic data representations.
 */
public class SpatialUtils {

	/**
	 * Creates an Envelope from a simple georss:box element. The coordinate reference
	 * system is EPSG 4326 (lat,lon axis order).
	 * @param boxNode An Element node (georss:box) containing the coordinates of the lower
	 * and upper corners.
	 * @return An Envelope object representing the given spatial extent, or null if it
	 * cannot be constructed (a runtime exception may have occurred).
	 * @see GeoRSS Simple
	 */
	public static Envelope envelopeFromSimpleGeoRSSBox(Node boxNode) {
		if (!boxNode.getNamespaceURI().equals(Namespaces.GEORSS)) {
			throw new IllegalArgumentException("Not a GeoRSS element.");
		}
		CoordinateReferenceSystem crs = CommonCRS.WGS84.geographic();
		GeneralEnvelope env = new GeneralEnvelope(crs);
		String[] coords = boxNode.getTextContent().trim().split("\\s+");
		if (coords.length != 4) {
			throw new IllegalArgumentException("Expected two coordinate tuples (lower and upper corners).");
		}
		double[] coordArray = new double[coords.length];
		for (int i = 0; i < coords.length; i++) {
			coordArray[i] = Double.parseDouble(coords[i]);
		}
		env.setEnvelope(coordArray);
		return env;
	}

	/**
	 * Creates a GML 3.2 envelope from a legacy GML 3.1 representation.
	 * @param oldEnvNode An element node representing a GML 3.1 envelope.
	 * @return A new gml:Envelope element, or null if the source node is not a GML 3.1
	 * envelope.
	 */
	public static Element createGML32Envelope(Node oldEnvNode) {
		if (!oldEnvNode.getNamespaceURI().equals(Namespaces.GML31)) {
			return null;
		}
		Element oldEnvelope = (Element) oldEnvNode;
		DocumentBuilder builder = null;
		try {
			builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
		}
		catch (ParserConfigurationException ex) {
			Logger.getLogger(SpatialUtils.class.getName()).log(Level.WARNING, null, ex);
		}
		Document doc = builder.newDocument();
		Element envelope = doc.createElementNS(Namespaces.GML, "Envelope");
		envelope.setAttribute("srsName", oldEnvelope.getAttribute("srsName"));
		Element lowerCorner = doc.createElementNS(Namespaces.GML, "lowerCorner");
		lowerCorner.setTextContent(
				oldEnvelope.getElementsByTagNameNS(Namespaces.GML31, "lowerCorner").item(0).getTextContent());
		envelope.appendChild(lowerCorner);
		Element upperCorner = doc.createElementNS(Namespaces.GML, "upperCorner");
		upperCorner.setTextContent(
				oldEnvelope.getElementsByTagNameNS(Namespaces.GML31, "upperCorner").item(0).getTextContent());
		envelope.appendChild(upperCorner);
		return envelope;
	}

}