com.jasonmheim.rollout.station.StationDataDownloader.java Source code

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Here is the source code for com.jasonmheim.rollout.station.StationDataDownloader.java

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/*
 * Copyright (C) 2014 Jason M. Heim
 *
 * 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 com.jasonmheim.rollout.station;

import android.util.Log;

import com.google.common.io.Closeables;
import com.google.gson.Gson;
import com.jasonmheim.rollout.data.StationList;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URLConnection;
import java.util.Date;
import java.util.concurrent.Callable;

import javax.inject.Inject;
import javax.inject.Provider;

/**
 * Handles downloading station data. To execute on something other than the current thread, submit
 * this as a {@link Callable}.
 */
public class StationDataDownloader implements Provider<StationList>, Callable<StationList> {

    private final Gson gson;
    private final Provider<Date> dateProvider;
    private final Provider<URLConnection> urlConnectionProvider;

    @Inject
    StationDataDownloader(Gson gson, Provider<Date> dateProvider,
            @StationData Provider<URLConnection> urlConnectionProvider) {
        this.gson = gson;
        this.dateProvider = dateProvider;
        this.urlConnectionProvider = urlConnectionProvider;
    }

    @Override
    public StationList get() {
        InputStream input = null;
        try {
            input = urlConnectionProvider.get().getInputStream();
            StationList stationList = gson.fromJson(new InputStreamReader(input), StationList.class);
            Log.i("Rollout", "Providing " + stationList.stationBeanList.size() + " stations.");
            stationList.timestamp = dateProvider.get().getTime();
            return stationList;
        } catch (RuntimeException ex) {
            Log.w("Rollout", "Failed to deserialize station list data from service", ex);
            return null;
        } catch (IOException ex) {
            Log.w("Rollout", "Failed to download station list data.", ex);
            return null;
        } finally {
            Closeables.closeQuietly(input);
        }
    }

    @Override
    public StationList call() {
        return get();
    }
}