ca.ualberta.cmput301w14t08.geochan.managers.GeoLocationLogIOManager.java Source code

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Here is the source code for ca.ualberta.cmput301w14t08.geochan.managers.GeoLocationLogIOManager.java

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/*
 * Copyright 2014 Artem Chikin
 * Copyright 2014 Artem Herasymchuk
 * Copyright 2014 Tom Krywitsky
 * Copyright 2014 Henry Pabst
 * Copyright 2014 Bradley Simons
 * 
 * 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.
 */

package ca.ualberta.cmput301w14t08.geochan.managers;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.lang.reflect.Type;
import java.util.ArrayList;

import android.content.Context;
import ca.ualberta.cmput301w14t08.geochan.helpers.GsonHelper;
import ca.ualberta.cmput301w14t08.geochan.models.GeoLocation;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

/**
 * Responsible for persistency of the log of used geolocations. Contains methdos
 * to serialize/deserialize log. Is a singleton.
 * 
 * @author Artem Chikin
 */
public class GeoLocationLogIOManager {
    private static GeoLocationLogIOManager instance;
    private Context context;
    private Gson gson;
    private static final String FILENAME = "geolog.sav";

    private GeoLocationLogIOManager(Context context) {
        this.context = context;
        this.gson = GsonHelper.getOnlineGson();
    }

    /**
     * Returns the instance of the GeoLocationLogIOManager.
     * @param context The Context in which the GeoLocationLogIOManager is running.
     * @return The GeolocationLogIOManager instance.
     */
    public static GeoLocationLogIOManager getInstance(Context context) {
        if (instance == null) {
            instance = new GeoLocationLogIOManager(context);
        }
        return instance;
    }

    /**
     * Serializes an ArrayList of Geolocations and saves them.
     * @param list The ArrayList of GeoLocations to serialize.
     */
    public void serializeLog(ArrayList<GeoLocation> list) {
        try {
            String json = gson.toJson(list);
            FileOutputStream f = context.openFileOutput(FILENAME, Context.MODE_PRIVATE);
            BufferedWriter w = new BufferedWriter(new OutputStreamWriter(f));
            w.write(json);
            w.close();
            f.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * Deserializes and returns the GeoLocations stored in our app.
     * @return An ArrayList of the stored GeoLocations.
     */
    public ArrayList<GeoLocation> deserializeLog() {
        ArrayList<GeoLocation> list = new ArrayList<GeoLocation>();
        try {
            FileInputStream f = context.openFileInput(FILENAME);
            BufferedReader r = new BufferedReader(new InputStreamReader(f));
            String json = "";
            String temp = "";
            temp = r.readLine();
            while (temp != null) {
                json = json + temp;
                temp = r.readLine();
            }
            r.close();
            f.close();
            Type type = new TypeToken<ArrayList<GeoLocation>>() {
            }.getType();
            list = gson.fromJson(json, type);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return list;
    }
}