se252.jan15.calvinandhobbes.project0.IIScCampusMapRDBMS_GETService.java Source code

Introduction

Here is the source code for se252.jan15.calvinandhobbes.project0.IIScCampusMapRDBMS_GETService.java

Source

package se252.jan15.calvinandhobbes.project0;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.InetSocketAddress;
import java.net.MalformedURLException;
import java.net.Proxy;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

import javax.ws.rs.DefaultValue;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;

import org.json.JSONArray;
import org.json.JSONObject;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;

/**
 * Echo web service exposed at "echo" path relative to base URI
 * 
 * @author Yogesh Simmhan
 * @version 1.0
 * @see <a href="http://www.serc.iisc.ernet.in/~simmhan/SE252/">IISc SERC 'SE252:Intro to Cloud Computing' Course Webpage</a>
 * 
 * (c) Yogesh Simmhan, 2015
 * This work is licensed under a Attribution 4.0 International (CC BY 4.0).
 * http://creativecommons.org/licenses/by/4.0/
 */

@Path("dataRDBMS")
public class IIScCampusMapRDBMS_GETService {
    /**
     * Method handling HTTP GET requests. The request expects a "msg" input parameter with value of type string. 
     * The returned object will be sent to the client as JSON media type.
     *
     * @return JSON form of EchoMessage will be returned as response.
     */
    private static String placeLink = "https://maps.googleapis.com/maps/api/place/nearbysearch/json?";
    private static String apiGoogle = "AIzaSyCIthNbg4lwx-LWHxXMyw1wHBYssjmAuDA";
    private static String pagetoken = "";
    private static Calendar date = Calendar.getInstance();
    private static LayerInfo[] cachedLayers = null;

    private static LoadingCache<String, Object[]> categoryCache = null;

    public static void cacheInit() {
        categoryCache = CacheBuilder.newBuilder().maximumSize(7) // maximum 7 records can be cached
                .expireAfterAccess(10, TimeUnit.MINUTES) // cache will expire after 10 minutes of access
                .build(new CacheLoader<String, Object[]>() { // build the cacheloader
                    @Override
                    public Object[] load(String category) throws Exception {
                        return getCategoryData(category);
                    }
                });
    }

    private static String readAll(Reader rd) throws IOException {
        StringBuilder sb = new StringBuilder();
        int cp;
        while ((cp = rd.read()) != -1) {
            sb.append((char) cp);
        }
        return sb.toString();
    }

    private static JSONObject getJSON(String url) {
        Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("proxy.iisc.ernet.in", 3128));
        InputStream is;
        try {
            is = new URL(url).openConnection(proxy).getInputStream();
            BufferedReader rd = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8")));
            String jsonText = readAll(rd);
            JSONObject json = new JSONObject(jsonText);
            is.close();
            return json;
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    private static LayerInfo[] diningOutside() {
        ArrayList<LayerInfo> layers = new ArrayList<LayerInfo>();

        if (date.get(Calendar.DATE) != Calendar.getInstance().get(Calendar.DATE))
            date = Calendar.getInstance();
        else if (cachedLayers != null)
            return cachedLayers;

        for (int i = 0; i < 3; i++) {
            String url = placeLink + "location=13.020168,77.567319&radius=1500&types=restaurant&key=" + apiGoogle
                    + "&pagetoken=" + pagetoken;
            JSONObject jsonObj = getJSON(url);
            if (jsonObj.has("next_page_token"))
                pagetoken = jsonObj.getString("next_page_token");
            JSONArray jsonPlaces = jsonObj.getJSONArray("results");
            int len = jsonPlaces.length();
            for (int j = 0; j < len; j++) {
                JSONObject temp = jsonPlaces.getJSONObject(j);
                LayerInfo layer = new LayerInfo(temp);
                float lat = layer.getLatitude(), lon = layer.getLongitude();
                float minLat = 13.011952F, minLon = 77.561869F, maxLat = 13.027422F, maxLon = 77.571224F;
                if (!(minLat < lat && lat < maxLat && minLon < lon && lon < maxLon))
                    layers.add(layer);
            }
            try {
                Thread.sleep(2000);
            } catch (InterruptedException ex) {
                Thread.currentThread().interrupt();
            }
        }
        pagetoken = "";
        cachedLayers = new LayerInfo[layers.size()];
        layers.toArray(cachedLayers);
        return cachedLayers;
    }

    public static Object[] getCategoryData(String category) {
        System.out.println("called " + category);
        Object[] layerArray = null;
        if (category.equals("AllCategories"))
            layerArray = DBConn.getCategories();
        else if (category.equals("Event"))
            layerArray = DBConn.getEvents();
        else if (!category.equals("Dining Outside"))
            layerArray = DBConn.getCategoryInfo(category);
        else
            layerArray = diningOutside();
        return layerArray;
    }

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    public static Response IIScCampusMapGet(
            @DefaultValue("AllCategories") @QueryParam("category") String category) {
        Object[] layers = null;
        try {
            layers = categoryCache.get(category);
        } catch (ExecutionException e) {
            e.printStackTrace();
        }
        return Response.ok(layers, MediaType.APPLICATION_JSON).header("Access-Control-Allow-Origin", "*").build();
    }
}