dk.laundav.locationservice.service.ReverseGeocoder.java Source code

Introduction

Here is the source code for dk.laundav.locationservice.service.ReverseGeocoder.java

Source

package dk.laundav.locationservice.service;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.HashMap;
import java.util.Locale;

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

import dk.laundav.data.AbstractLocationObject;
import dk.laundav.data.LocationObject;
import dk.laundav.data.ReverseGeocoderObject;

/* 
 * Copyright 2013 David Laundav
 *
 * Licensed 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.
 */

/*
 * References:
 *       
 *       JSONReader:
 *       http://stackoverflow.com/a/4308662/2399772
 * 
 *       Parsing JSON:
 *       http://stackoverflow.com/a/11875002/2399772
 */

public class ReverseGeocoder {

    private static String readAll(Reader rd) throws IOException {

        int cp;
        StringBuilder sb = new StringBuilder();

        while ((cp = rd.read()) != -1) {
            sb.append((char) cp);
        }

        return sb.toString();
    }

    public static JSONObject readJSONFromUrl(String url) throws IOException, JSONException {

        InputStream is = new URL(url).openStream();

        try {
            BufferedReader br = new BufferedReader(new InputStreamReader(is, Charset.forName("UTF-8")));
            String jsonText = readAll(br);
            JSONObject json = new JSONObject(jsonText);
            return json;
        }

        finally {
            is.close();
        }
    }

    public static void getAddressComponents(ReverseGeocoderObject location) throws IOException, JSONException {

        JSONObject json = readJSONFromUrl(addLocationToUrl(location));

        JSONArray resultsArray = json.getJSONArray("results");
        JSONObject jsonResult = resultsArray.getJSONObject(0);

        String formatted_address = jsonResult.getString("formatted_address");
        location.setAddress(formatted_address);

        // use this method to iterate through the list of components
        JSONArray addressComponentsArray = jsonResult.getJSONArray("address_components");

        for (int i = 0; i < addressComponentsArray.length(); i++) {
            JSONObject jsonAddressComponent = addressComponentsArray.getJSONObject(i);
            String value = jsonAddressComponent.getString("long_name");

            JSONArray typesArray = jsonAddressComponent.getJSONArray("types");
            String key = typesArray.getString(0);

            location.setAddressComponent(key, value);

        }

    }

    // Set the URL
    private static String addLocationToUrl(AbstractLocationObject location) {

        String latitude = String.format(Locale.US, "%.10f", location.getLatitude());
        String longitude = String.format(Locale.US, "%.10f", location.getLongitude());

        String url = "http://maps.googleapis.com/maps/api/geocode/json?latlng=" + longitude + "," + latitude
                + "&sensor=true";

        System.out.println(url);

        return url;

    }

}