org.envirocar.app.json.TrackDecoder.java Source code

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Here is the source code for org.envirocar.app.json.TrackDecoder.java

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/* 
 * enviroCar 2013
 * Copyright (C) 2013  
 * Martin Dueren, Jakob Moellers, Gerald Pape, Christopher Stephan
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 * 
 */
package org.envirocar.app.json;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.ParseException;
import org.apache.http.util.EntityUtils;
import org.envirocar.app.dao.exception.TrackRetrievalException;
import org.envirocar.app.exception.ServerException;
import org.envirocar.app.storage.DbAdapterImpl;
import org.envirocar.app.storage.Track;
import org.envirocar.app.util.Util;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class TrackDecoder {

    public Integer resolveTrackCount(HttpResponse response) throws TrackRetrievalException {
        try {
            return Util.resolveResourceCount(response);
        } catch (ServerException e) {
            throw new TrackRetrievalException(e);
        }
    }

    public List<String> getResourceIds(InputStream response) throws ParseException, IOException, JSONException {
        String result = Util.consumeInputStream(response).toString();

        JSONObject json = new JSONObject(result);

        JSONArray tracks = json.getJSONArray("tracks");

        if (tracks != null && tracks.length() > 0) {
            List<String> list = new ArrayList<String>(tracks.length());

            JSONObject o;
            for (int i = 0; i < tracks.length(); i++) {
                o = tracks.getJSONObject(i);
                list.add(o.getString("id"));
            }

            return list;
        }

        return Collections.emptyList();
    }

    public Track fromJson(HttpEntity content)
            throws ParseException, IOException, JSONException, java.text.ParseException {
        String result = EntityUtils.toString(content);
        return fromJson(new JSONObject(result));
    }

    public Track fromJson(JSONObject json) throws JSONException, java.text.ParseException {
        return Track.fromJson(json);
    }

    public Track fromJson(InputStream jsonStream) throws JSONException, java.text.ParseException, IOException {
        /*
         * TODO use GSON or the like to efficiently parse Streams
         */
        CharSequence contents = Util.consumeInputStream(jsonStream);
        return fromJson(contents);
    }

    public Track fromJson(CharSequence contents) throws JSONException, java.text.ParseException {
        return fromJson(new JSONObject(contents.toString()));
    }

    public String resolveLocation(HttpResponse response) throws TrackRetrievalException {
        String location = null;
        Header h = response.getFirstHeader("Location");

        if (h != null) {
            location = h.getValue();
        } else {
            throw new TrackRetrievalException("Could not parse the 'Location' Header.");
        }

        String trackid = location.substring(location.lastIndexOf("/") + 1, location.length());
        return trackid;
    }

}