adapter.sos.BasicSensorObservationServiceClient.java Source code

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Here is the source code for adapter.sos.BasicSensorObservationServiceClient.java

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/*******************************************************************************
 * Copyright (c) 2012 IDIRA project.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/gpl.html
 * 
 * Contributors:
 *     Aggelos Biboudis - initial API and implementation
 ******************************************************************************/
package adapter.sos;

import java.io.IOException;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.ParseException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.DOMException;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import adapter.davis.DavisSensor;
import adapter.sos.exceptions.SOSException;
import adapter.utils.FileUtils;

/**
 * @author Aggelos Biboudis
 * Basic class for communication with an OGC SOS service.
 * It can throw SOS exceptions.
 */

public class BasicSensorObservationServiceClient {
    private HttpClient httpclient;
    Logger logger = LoggerFactory.getLogger(DavisSensor.class);

    public BasicSensorObservationServiceClient() {
        this.httpclient = new DefaultHttpClient();
    }

    public void postXml(String strXML, String serviceURL) throws SOSException {

        HttpPost httppost = new HttpPost(serviceURL);
        HttpEntity entity = null;
        HttpResponse response = null;
        try {
            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);

            nameValuePairs.add(new BasicNameValuePair("request", strXML));

            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

            response = httpclient.execute(httppost);

            entity = response.getEntity();

            int code = response.getStatusLine().getStatusCode();

            if (code != 200) {
                throw new SOSException("Server replied with http error code: " + code);
            }

            examineReponse(entity);
        } catch (IOException e) {
            try {
                EntityUtils.consume(entity);
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            throw new SOSException("Cannot execute post: " + e.getCause());
        }
    }

    private void examineReponse(HttpEntity entity) throws SOSException {
        try {
            if (entity != null) {
                String xmlString = EntityUtils.toString(entity);

                DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                DocumentBuilder db = factory.newDocumentBuilder();
                InputSource inStream = new InputSource();
                inStream.setCharacterStream(new StringReader(xmlString));
                Document doc = db.parse(inStream);

                String value;

                NodeList nlExc = doc.getElementsByTagName("ows:ExceptionText");
                for (int i = 0; i < nlExc.getLength(); i++) {
                    if (nlExc.item(i).getNodeType() == org.w3c.dom.Node.ELEMENT_NODE) {
                        org.w3c.dom.Element nameElement = (org.w3c.dom.Element) nlExc.item(i);
                        value = nameElement.getFirstChild().getNodeValue().trim();
                        throw new SOSException(value, "Error in response from SOS service.");
                    }
                }

                NodeList nl;
                nl = doc.getElementsByTagName("sos:AssignedObservationId");
                for (int i = 0; i < nl.getLength(); i++) {
                    if (nl.item(i).getNodeType() == org.w3c.dom.Node.ELEMENT_NODE) {
                        org.w3c.dom.Element nameElement = (org.w3c.dom.Element) nl.item(i);
                        value = nameElement.getFirstChild().getNodeValue().trim();
                        logger.info("AssignedObservationId [" + value + "]");
                    }
                }
            }
        } catch (ParseException | DOMException | ParserConfigurationException | IOException | SAXException e) {
            e.printStackTrace();
        }
    }

    public void postFromXml(String pathToXMLFile, String serviceURL) throws IOException, SOSException {
        String xmlToPost = FileUtils.readFileAsString(pathToXMLFile);

        postXml(xmlToPost, serviceURL);
    }
}