| // Copyright 2015 The Vanadium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package io.v.positioning; |
| |
| import com.google.appengine.api.datastore.DatastoreService; |
| import com.google.appengine.api.datastore.DatastoreServiceFactory; |
| import com.google.appengine.api.datastore.Entity; |
| import com.google.appengine.api.datastore.Query; |
| |
| import org.json.JSONObject; |
| |
| import java.io.BufferedReader; |
| import java.io.IOException; |
| |
| import javax.servlet.http.HttpServlet; |
| import javax.servlet.http.HttpServletRequest; |
| import javax.servlet.http.HttpServletResponse; |
| |
| /** |
| * Servlet that is deployed on GAE,handles GET and POST requests from android |
| * Proximity app to save/retrieve device's GPS location to/from Datastore. |
| */ |
| public class GpsLocationServlet extends HttpServlet { |
| |
| /** |
| * Processes a GET request and returns device's GPS location |
| * |
| * @param req The servlet request that includes <b>"androidId"</b> parameter |
| * @param resp The servlet response with lat/long information |
| */ |
| @Override |
| public void doGet(HttpServletRequest req, HttpServletResponse resp) |
| throws IOException { |
| resp.setContentType("text/plain"); |
| DatastoreService datastore = DatastoreServiceFactory.getDatastoreService(); |
| Query.Filter propertyFilter = new Query.FilterPredicate("androidId", Query.FilterOperator.EQUAL, req.getParameter("androidId")); |
| Query q = new Query("gps").setFilter(propertyFilter); |
| Entity e = datastore.prepare(q).asSingleEntity(); |
| if (e == null) { |
| resp.getWriter().println("Missing location for the given androidId."); |
| } else { |
| resp.getWriter().println("(" + e.getProperty("latitude") + ", " + e.getProperty("longitude") + ")"); |
| } |
| } |
| |
| /** |
| * Processes a POST request to save device's GPS location |
| * |
| * @param req The servlet request that includes JSONObject with properties to be saved |
| * @param resp The servlet response informing a user if the request was successful or not |
| */ |
| @Override |
| public void doPost(HttpServletRequest req, HttpServletResponse resp) throws IOException { |
| resp.setContentType("text/plain"); |
| BufferedReader br = req.getReader(); |
| try { |
| JSONObject jo = new JSONObject(br.readLine()); |
| DatastoreService datastore = DatastoreServiceFactory.getDatastoreService(); |
| Entity entity = new Entity("gps"); |
| entity.setProperty("androidId", jo.get("androidId")); |
| entity.setProperty("latitude", jo.get("latitude")); |
| entity.setProperty("longitude", jo.get("longitude")); |
| entity.setProperty("deviceTime", jo.get("deviceTime")); |
| entity.setProperty("serverTime", System.currentTimeMillis()); |
| datastore.put(entity); |
| resp.getWriter().println("New GPS location added."); |
| } catch (Exception e) { |
| resp.getWriter().println("Recording failed. " + e.getMessage()); |
| } |
| } |
| } |