eu.smartfp7.foursquare.utils.Settings.java Source code

Introduction

Here is the source code for eu.smartfp7.foursquare.utils.Settings.java

Source

/**  
 * SMART FP7 - Search engine for MultimediA enviRonment generated contenT
 * Webpage: http://smartfp7.eu
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. 
 * 
 * The Original Code is Copyright (c) 2012-2014 the University of Glasgow
 * All Rights Reserved
 * 
 * Contributor(s):
 *  @author Romain Deveaud <romain.deveaud at glasgow.ac.uk>
 */

package eu.smartfp7.foursquare.utils;

import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.lang.StringUtils;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

/**
 * This class manages the settings of the attendance crawler.
 * The different options can be changed in the etc/settings.json file.
 * Currently, the options that are supported are:
 *    - foursquare_api_accounts
 *    - timezones
 *    - crawl_folder
 * 
 * See README.md for more information.
 * 
 * This class is a singleton, hence the Settings object must be retrieved by
 * calling the `getInstance()` method.
 *
 */
public class Settings {

    private JsonObject settings_json;
    private static Settings instance = null;

    protected Settings() {
        // We load the settings file and parse its JSON only once.
        try {
            JsonParser parser = new JsonParser();
            this.settings_json = parser
                    .parse(StringUtils
                            .join(Files.readAllLines(Paths.get("etc/settings.json"), StandardCharsets.UTF_8), " "))
                    .getAsJsonObject();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static Settings getInstance() {
        if (instance == null)
            instance = new Settings();

        return instance;
    }

    /**
     * Checks if all the files and directories needed by the crawler already
     * exist, creates them otherwise.
     */
    public void checkFileHierarchy(String city) {
        String folder = getFolder();

        String[] dirs_to_check = { folder + city, folder + city + File.separator + "attendances_crawl",
                folder + city + File.separator + "log", folder + city + File.separator + "foursquare_venues",
                folder + city + File.separator + ".exhaustive_crawl",
                folder + city + File.separator + ".deleted", };

        for (String dir : dirs_to_check) {
            File dir_f = new File(dir);
            if (!dir_f.exists())
                dir_f.mkdirs();
        }
    }

    /** Returns the folder where all the data will be downloaded. */
    public String getFolder() {
        String path = this.settings_json.get("crawl_folder").getAsString();
        if (path.charAt(path.length() - 1) != File.separatorChar)
            path += File.separator;

        return path;
    }

    /** Returns the Foursquare API credentials for a given city. */
    public Map<String, String> getCityCredentials(String city) {
        Map<String, String> credentials = new HashMap<String, String>();

        JsonObject cred_map = this.settings_json.get("foursquare_api_accounts").getAsJsonObject().get(city)
                .getAsJsonObject();
        credentials.put("client_secret", cred_map.get("client_secret").getAsString());
        credentials.put("client_id", cred_map.get("client_id").getAsString());

        return credentials;
    }

    /** Returns the timezone of a given city. */
    public String getCityTimezone(String city) {
        return this.settings_json.get("timezones").getAsJsonObject().get(city).getAsString();
    }

    /** Returns the longitude of the geographical center of a given city. */
    public Double getCityCenterLng(String city) {
        return this.settings_json.get("centers").getAsJsonObject().get(city).getAsJsonObject().get("lng")
                .getAsDouble();
    }

    /** Returns the latitude of the geographical center of a given city. */
    public Double getCityCenterLat(String city) {
        return this.settings_json.get("centers").getAsJsonObject().get(city).getAsJsonObject().get("lat")
                .getAsDouble();
    }

}