Java tutorial
/*********************************************************************************************** * Project: Tourist Guide System Toguis * University: UNIAJC * Authors: Julieth Candia and Carlos Morante * Year: 2014 - 2015 * Version: 1.0 * License: GPL V2 * Original code by: Emil Adjiev * WebSite: http://blog-emildesign.rhcloud.com/?p=822 ***********************************************************************************************/ package co.edu.uniajc.vtf.utils; import java.io.InputStream; import java.util.ArrayList; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.apache.http.HttpResponse; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.protocol.BasicHttpContext; import org.apache.http.protocol.HttpContext; import org.w3c.dom.Document; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import android.util.Log; import com.google.android.gms.maps.model.LatLng; public class GMapV2Direction { public final static String MODE_DRIVING = "driving"; public final static String MODE_WALKING = "walking"; public GMapV2Direction() { } public Document getDocument(LatLng start, LatLng end, String mode, String language) { //query the web service to get directions data String url = "http://maps.googleapis.com/maps/api/directions/xml?" + "origin=" + start.latitude + "," + start.longitude + "&destination=" + end.latitude + "," + end.longitude + "&language=" + language + "&sensor=false&units=metric&mode=" + MODE_WALKING; try { HttpClient httpClient = new DefaultHttpClient(); HttpContext localContext = new BasicHttpContext(); HttpPost httpPost = new HttpPost(url); HttpResponse response = httpClient.execute(httpPost, localContext); InputStream in = response.getEntity().getContent(); DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder(); Document doc = builder.parse(in); return doc; } catch (Exception e) { e.printStackTrace(); } return null; } public String getDurationText(Document doc) { NodeList nl1 = doc.getElementsByTagName("duration"); Node node1 = nl1.item(0); NodeList nl2 = node1.getChildNodes(); Node node2 = nl2.item(getNodeIndex(nl2, "text")); Log.i("DurationText", node2.getTextContent()); return node2.getTextContent(); } public int getDurationValue(Document doc) { NodeList nl1 = doc.getElementsByTagName("duration"); Node node1 = nl1.item(0); NodeList nl2 = node1.getChildNodes(); Node node2 = nl2.item(getNodeIndex(nl2, "value")); Log.i("DurationValue", node2.getTextContent()); return Integer.parseInt(node2.getTextContent()); } public String getDistanceText(Document doc) { NodeList nl1 = doc.getElementsByTagName("distance"); Node node1 = nl1.item(0); NodeList nl2 = node1.getChildNodes(); Node node2 = nl2.item(getNodeIndex(nl2, "text")); Log.i("DistanceText", node2.getTextContent()); return node2.getTextContent(); } public int getDistanceValue(Document doc) { NodeList nl1 = doc.getElementsByTagName("distance"); Node node1 = nl1.item(0); NodeList nl2 = node1.getChildNodes(); Node node2 = nl2.item(getNodeIndex(nl2, "value")); Log.i("DistanceValue", node2.getTextContent()); return Integer.parseInt(node2.getTextContent()); } public String getStartAddress(Document doc) { NodeList nl1 = doc.getElementsByTagName("start_address"); Node node1 = nl1.item(0); Log.i("StartAddress", node1.getTextContent()); return node1.getTextContent(); } public String getEndAddress(Document doc) { NodeList nl1 = doc.getElementsByTagName("end_address"); Node node1 = nl1.item(0); Log.i("StartAddress", node1.getTextContent()); return node1.getTextContent(); } public String getCopyRights(Document doc) { NodeList nl1 = doc.getElementsByTagName("copyrights"); Node node1 = nl1.item(0); Log.i("CopyRights", node1.getTextContent()); return node1.getTextContent(); } public ArrayList<DirectionsEntity> getDirection(Document doc) { NodeList nl1, nl2, nl3; ArrayList<DirectionsEntity> loListDirections = new ArrayList<DirectionsEntity>(); //format the data before to return it to the activity nl1 = doc.getElementsByTagName("step"); if (nl1.getLength() > 0) { for (int i = 0; i < nl1.getLength(); i++) { DirectionsEntity loDirectionPoint = new DirectionsEntity(); ArrayList<LatLng> loListGeopoints = new ArrayList<LatLng>(); Node node1 = nl1.item(i); nl2 = node1.getChildNodes(); Node locationNode = nl2.item(getNodeIndex(nl2, "start_location")); nl3 = locationNode.getChildNodes(); Node latNode = nl3.item(getNodeIndex(nl3, "lat")); double lat = Double.parseDouble(latNode.getTextContent()); Node lngNode = nl3.item(getNodeIndex(nl3, "lng")); double lng = Double.parseDouble(lngNode.getTextContent()); loListGeopoints.add(new LatLng(lat, lng)); locationNode = nl2.item(getNodeIndex(nl2, "polyline")); nl3 = locationNode.getChildNodes(); latNode = nl3.item(getNodeIndex(nl3, "points")); ArrayList<LatLng> arr = decodePoly(latNode.getTextContent()); for (int j = 0; j < arr.size(); j++) { loListGeopoints.add(new LatLng(arr.get(j).latitude, arr.get(j).longitude)); } locationNode = nl2.item(getNodeIndex(nl2, "end_location")); nl3 = locationNode.getChildNodes(); latNode = nl3.item(getNodeIndex(nl3, "lat")); lat = Double.parseDouble(latNode.getTextContent()); lngNode = nl3.item(getNodeIndex(nl3, "lng")); lng = Double.parseDouble(lngNode.getTextContent()); loListGeopoints.add(new LatLng(lat, lng)); loDirectionPoint.setGeopoint(loListGeopoints); Node loDataNode = null; locationNode = nl2.item(getNodeIndex(nl2, "duration")); nl3 = locationNode.getChildNodes(); loDataNode = nl3.item(getNodeIndex(nl3, "text")); loDirectionPoint.setDuration(loDataNode.getTextContent()); locationNode = nl2.item(getNodeIndex(nl2, "distance")); nl3 = locationNode.getChildNodes(); loDataNode = nl3.item(getNodeIndex(nl3, "text")); loDirectionPoint.setDistance(loDataNode.getTextContent()); locationNode = nl2.item(getNodeIndex(nl2, "html_instructions")); loDirectionPoint.setInstructions(locationNode.getTextContent()); loListDirections.add(loDirectionPoint); } } return loListDirections; } private int getNodeIndex(NodeList nl, String nodename) { for (int i = 0; i < nl.getLength(); i++) { if (nl.item(i).getNodeName().equals(nodename)) return i; } return -1; } private ArrayList<LatLng> decodePoly(String encoded) { //help to decode the data of the polyline ArrayList<LatLng> poly = new ArrayList<LatLng>(); int index = 0, len = encoded.length(); int lat = 0, lng = 0; while (index < len) { int b, shift = 0, result = 0; do { b = encoded.charAt(index++) - 63; result |= (b & 0x1f) << shift; shift += 5; } while (b >= 0x20); int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1)); lat += dlat; shift = 0; result = 0; do { b = encoded.charAt(index++) - 63; result |= (b & 0x1f) << shift; shift += 5; } while (b >= 0x20); int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1)); lng += dlng; LatLng position = new LatLng((double) lat / 1E5, (double) lng / 1E5); poly.add(position); } return poly; } }