Java tutorial
/* See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * Esri Inc. licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.esri.gpt.server.openls.provider.services.reversegeocode; import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; import java.io.StringReader; import java.net.URL; import java.net.URLConnection; import java.util.logging.Level; import java.util.logging.Logger; import javax.servlet.http.HttpServletRequest; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.xpath.XPath; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathExpressionException; import org.json.JSONObject; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.xml.sax.InputSource; import com.esri.gpt.server.csw.provider.components.OwsException; import com.esri.gpt.server.openls.provider.components.IOperationProvider; import com.esri.gpt.server.openls.provider.components.IProviderFactory; import com.esri.gpt.server.openls.provider.components.IResponseGenerator; import com.esri.gpt.server.openls.provider.components.OperationContext; import com.esri.gpt.server.openls.provider.util.Address; import com.esri.gpt.server.openls.provider.util.GeocodedAddress; /** * Provides the OpenLS ReverseGeocode operation. */ public class ReverseGeocodeProvider implements IOperationProvider { /** class variables ========================================================= */ /** The Logger. */ private static Logger LOGGER = Logger.getLogger(ReverseGeocodeProvider.class.getName()); /** constructors ============================================================ */ /** Default constructor */ public ReverseGeocodeProvider() { super(); } /** methods ================================================================= */ /** * Generates the response. * @param context the operation context * @throws Exception if a processing exception occurs */ private void generateResponse(OperationContext context) throws Exception { IProviderFactory factory = context.getProviderFactory(); IResponseGenerator generator = factory.makeResponseGenerator(context); if (generator == null) { String msg = "IProviderFactory.makeResponseGenerator: instantiation failed."; LOGGER.log(Level.SEVERE, msg); throw new OwsException(msg); } else { generator.generateResponse(context); } } /** * Handles a URL based request (HTTP GET). * @param context the operation context * @param request the HTTP request * @throws Exception if a processing exception occurs */ public void handleGet(OperationContext context, HttpServletRequest request) throws Exception { // initialize LOGGER.finer("Handling request URL..."); throw new OwsException("HTTP Get is not supported for this operation."); } /** * Handles an XML based request (normally HTTP POST). * @param context the operation context * @param root the root node * @param xpath an XPath to enable queries (properly configured with name spaces) * @throws Exception */ public void handleXML(OperationContext context, Node root, XPath xpath) throws Exception { // initialize LOGGER.finer("Handling ReverseGeocodeRequest request XML..."); // find ReverseGeocodeRequest node String locator = "xls:ReverseGeocodeRequest"; Node ndReq = (Node) xpath.evaluate(locator, root, XPathConstants.NODE); if (ndReq != null) { GeocodedAddress addr = null; parseRequest(context, ndReq, xpath); try { addr = executeRequest(context); } catch (Throwable e) { e.printStackTrace(); } context.getRequestOptions().getReverseGeocodeOptions().setgAddr(addr); } // generate the response generateResponse(context); } /** * Parses reverse geocode request. * @param context * @param ndReq * @param xpath * @throws XPathExpressionException */ private void parseRequest(OperationContext context, Node ndReq, XPath xpath) throws XPathExpressionException { ReverseGeocodeParams reqParams = context.getRequestOptions().getReverseGeocodeOptions(); Node ndPosition = (Node) xpath.evaluate("xls:Position", ndReq, XPathConstants.NODE); if (ndPosition != null) { Node ndPoint = (Node) xpath.evaluate("gml:Point", ndPosition, XPathConstants.NODE); if (ndPoint != null) { Node ndPos = (Node) xpath.evaluate("gml:pos", ndPoint, XPathConstants.NODE); if (ndPos != null) { String[] vals = ndPos.getTextContent().split(" "); reqParams.setLat(vals[0]); reqParams.setLng(vals[1]); } } } Node ndPreference = (Node) xpath.evaluate("xls:ReverseGeocodePreference", ndReq, XPathConstants.NODE); if (ndPreference != null) { reqParams.setPreference(ndPreference.getTextContent()); } } /** * Processes and publishes the XML document child nodes associated with * the parent action. * @param context the operation context * @param publisher the authenticated publisher * @param typeName the CSW collection type * @param handle a client supplied name (can be echoed within the response) * @param xmlNodes a list of child nodes containing XML's to publish * @return * @throws Throwable */ private GeocodedAddress executeRequest(OperationContext context) throws Throwable { long t1 = System.currentTimeMillis(); ReverseGeocodeParams params = context.getRequestOptions().getReverseGeocodeOptions(); String srvCfg = context.getRequestContext().getApplicationConfiguration().getCatalogConfiguration() .getParameters().getValue("openls.reverseGeocode"); String sUrl = srvCfg + "/reverseGeocode?" + makeReverseGeocodeRequest(params.getLat(), params.getLng(), "json", 0); URL url = new URL(sUrl); URLConnection conn = url.openConnection(); String line = ""; String sResponse = ""; InputStream is = conn.getInputStream(); InputStreamReader isr = new InputStreamReader(is); BufferedReader rd = new BufferedReader(isr); while ((line = rd.readLine()) != null) { sResponse += line; } rd.close(); GeocodedAddress addr = parseReverseGeocodeResponse(sResponse); long t2 = System.currentTimeMillis(); LOGGER.info("PERFORMANCE: " + (t2 - t1) + " ms spent performing service"); return addr; } /* * .../reverseGeocode?location=-71.458961673001,41.83176073543&distance=0&f=pjson */ private String makeReverseGeocodeRequest(String x, String y, String format, double distance) { StringBuffer sReverseGeocodeRequest = new StringBuffer(); sReverseGeocodeRequest.append("location=").append(x).append(",").append(y); sReverseGeocodeRequest.append("&distance=").append(distance); sReverseGeocodeRequest.append("&f=").append(format); return sReverseGeocodeRequest.toString(); } /** * Parses reverse Geocode response. * @param sResponse * @return * @throws Throwable */ private GeocodedAddress parseReverseGeocodeResponse(String sResponse) throws Throwable { GeocodedAddress addr = new GeocodedAddress(); try { JSONObject jResponse = new JSONObject(sResponse); String xResponse = "<?xml version='1.0'?><response>" + org.json.XML.toString(jResponse) + "</response>"; LOGGER.info("XML from JSON = " + xResponse); String addressName = ""; Address respAddr = null; String street = ""; String intStreet = ""; String city = ""; String state = ""; String zip = ""; String scoreStr = ""; String x = ""; String y = ""; String country = "US"; DocumentBuilderFactory xfactory = DocumentBuilderFactory.newInstance(); DocumentBuilder db = xfactory.newDocumentBuilder(); InputSource inStream = new InputSource(); inStream.setCharacterStream(new StringReader(xResponse)); Document doc = db.parse(inStream); doc.getDocumentElement().normalize(); LOGGER.info("Root element " + doc.getDocumentElement().getNodeName()); NodeList nodeLst = doc.getChildNodes(); LOGGER.info("Information of all candidates:"); for (int s = 0; s < nodeLst.getLength(); s++) { Node fstNode = nodeLst.item(s); Element fstElmnt = (Element) fstNode; street = ""; intStreet = ""; city = ""; state = ""; zip = ""; scoreStr = ""; // LOCATION NodeList locationList = fstElmnt.getElementsByTagName("location"); Element fstNmElmnt = (Element) locationList.item(0); NodeList nodeY = fstNmElmnt.getElementsByTagName("y"); y = nodeY.item(0).getTextContent(); LOGGER.info("y = " + y); NodeList nodeX = fstNmElmnt.getElementsByTagName("x"); x = nodeX.item(0).getTextContent(); LOGGER.info("x = " + x); // ADDRESS NodeList addressList = fstElmnt.getElementsByTagName("address"); Node addressNode = addressList.item(0); addressName = addressList.item(0).getTextContent(); LOGGER.info("addressName = " + addressName); NodeList children = addressNode.getChildNodes(); for (int i = 0; i < children.getLength(); i++) { Node child = children.item(i); if (child.getNodeName().equalsIgnoreCase("address")) { street = child.getTextContent(); } else if (child.getNodeName().equalsIgnoreCase("city")) { city = child.getTextContent(); } else if (child.getNodeName().equalsIgnoreCase("zip")) { zip = child.getTextContent(); } else if (child.getNodeName().equalsIgnoreCase("state")) { state = child.getTextContent(); } else if (child.getNodeName().equalsIgnoreCase("country")) { country = child.getTextContent(); } } // SCORE NodeList scoreList = fstElmnt.getElementsByTagName("score"); if (scoreList != null && scoreList.getLength() > 0) { scoreStr = scoreList.item(0).getTextContent(); new Double(scoreStr); LOGGER.info("score = " + scoreStr); } // NOW ADD THIS RESULT TO THE OUTPUT pos respAddr = new Address(); respAddr.setStreet(street); respAddr.setMunicipality(city); respAddr.setPostalCode(zip); respAddr.setCountrySubdivision(state); respAddr.setIntersection(intStreet); addr.setX(x); addr.setY(y); addr.setAddress(respAddr); addr.setCountry(country); } } catch (Exception p_e) { LOGGER.severe("Caught Exception" + p_e.getMessage()); } return addr; } }