IIScCampusMapRDBMS_GETService.java

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();
    }
}