Android Open Source - grtransit Rider Alerts Activity

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License

The source code is released under:
GNU General Public License
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Java Source Code

/*
 * Copyright 2011 Giles Malet./*  w ww  . j  a  va 2  s  .  c om*/
 *
 * This file is part of GRTransit.
 * 
 * GRTransit 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.
 * 
 * GRTransit 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 GRTransit.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.kw.shrdlu.grtgtfs.Activities;

import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Base64;
import android.util.Log;
import android.view.Window;
import android.widget.Toast;

import net.kw.shrdlu.grtgtfs.LayoutAdapters.ListArrayAdapter;
import net.kw.shrdlu.grtgtfs.R;
import net.kw.shrdlu.grtgtfs.TwitterCredentials;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONTokener;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.List;
import java.util.Locale;

public class RiderAlertsActivity extends MenuListActivity {
  private static final String TAG = "RiderAlertsActivity";

  // The search string to get recent tweets from GRT Rider Alerts
  private final String TwitterURL = "https://api.twitter.com/1.1/statuses/user_timeline.json";
  private final String TwitterQry = "?screen_name=GRT_ROW&count=20&trim_user=true";

  private final String TwitterOauth = "https://api.twitter.com/oauth2/token";
  private static String AccessToken = null;

  private ListArrayAdapter mAdapter;
  private ArrayList<String[]> mListDetails;


  @Override
  public void onCreate(Bundle savedInstanceState) {
    mContext = this;

        // Will use the action bar progress bar
        requestWindowFeature(Window.FEATURE_PROGRESS);

        setContentView(R.layout.timeslayout);
    super.onCreate(savedInstanceState);

    mListDetails = new ArrayList<>();

        getActionBar().setTitle(R.string.twitter_querying_feed);
        getActionBar().setSubtitle(null);

    new ProcessTweets().execute();
  }

  /* Do the processing to load the ArrayAdapter for display. */
  private class ProcessTweets extends AsyncTask<Void, Integer, Void> {
    // static final String TAG = "ProcessBusStops";

    @Override
    protected void onPreExecute() {
            setProgressBarVisibility(true);
    }

    // Update the progress bar.
    @Override
    protected void onProgressUpdate(Integer... parms) {
      setProgress(parms[0]);
    }

    @Override
    protected Void doInBackground(Void... foo) {

      if (AccessToken == null) {
        String ConsumerKeyEnc, ConsumerSecretEnc, BearerToken, BearerToken64;
        ConsumerKeyEnc = Uri.encode(TwitterCredentials.ConsumerKey);
        ConsumerSecretEnc = Uri.encode(TwitterCredentials.ConsumerSecret);
        BearerToken = ConsumerKeyEnc + ":" + ConsumerSecretEnc;
        BearerToken64 = Base64.encodeToString(BearerToken.getBytes(), Base64.URL_SAFE | Base64.NO_WRAP);

        // Get the Twitter OAuth token
        final HttpClient httpclient = new DefaultHttpClient();
        final HttpPost httppost = new HttpPost(TwitterOauth);
        httppost.setHeader("Authorization", "Basic " + BearerToken64);

        publishProgress(15); // fake it

        try {
          final List<NameValuePair> nameValuePairs = new ArrayList<>(1);
          nameValuePairs.add(new BasicNameValuePair("grant_type", "client_credentials"));
          final UrlEncodedFormEntity entity = new UrlEncodedFormEntity(nameValuePairs);
          entity.setContentType("application/x-www-form-urlencoded;charset=UTF-8");
          httppost.setEntity(entity);

          // Execute HTTP Post Request
          final HttpResponse response = httpclient.execute(httppost);

          final StatusLine statusLine = response.getStatusLine();
          final int statusCode = statusLine.getStatusCode();
          if (statusCode == 200) {
            final HttpEntity responseEntity = response.getEntity();
            final String s = EntityUtils.toString(responseEntity);
            final JSONObject object = (JSONObject) new JSONTokener(s).nextValue();
            final String type = object.getString("token_type");
            final String token = object.getString("access_token");

            if (type.contentEquals("bearer") && !token.isEmpty()) {
              AccessToken = token;  // stash it
            }
          }
        } catch (final IOException | JSONException e) {
          e.printStackTrace();
        }
      }

      publishProgress(2500); // fake it
      if (AccessToken != null) {
        mListDetails = readTwitterFeed();
      }
      publishProgress(9000); // fake it

      return null;
    }

    @Override
    protected void onPostExecute(Void foo) {
            getActionBar().setTitle(R.string.title_rider_alerts);
            getActionBar().setSubtitle(null);
            setProgress(10000); // max -- makes it slide away

      if (mListDetails == null) {
        Toast.makeText(mContext, R.string.twitter_fetch_failed, Toast.LENGTH_LONG).show();
      } else if (mListDetails.isEmpty()) {
        Toast.makeText(mContext, R.string.twitter_fetch_nothing, Toast.LENGTH_LONG).show();
      } else {
        mAdapter = new ListArrayAdapter(mContext, R.layout.tweetlayout, mListDetails);
        mContext.setListAdapter(mAdapter);
      }
    }
  }

  /**
   * Get the latest twitter info. Some of this copied from http://www.vogella.com/articles/AndroidJSON/article.html
   */
    ArrayList<String[]> readTwitterFeed() {
    final StringBuilder builder = new StringBuilder();
    final HttpClient client = new DefaultHttpClient();
    final HttpGet httpGet = new HttpGet(TwitterURL + TwitterQry);
    httpGet.setHeader("Authorization", "Bearer " + AccessToken);

    try {
      final HttpResponse response = client.execute(httpGet);

      final StatusLine statusLine = response.getStatusLine();
      final int statusCode = statusLine.getStatusCode();
      if (statusCode == 200) {
        final HttpEntity entity = response.getEntity();
        final InputStream content = entity.getContent();
        final BufferedReader reader = new BufferedReader(new InputStreamReader(content));
        String line;
        while ((line = reader.readLine()) != null) {
          builder.append(line);
        }
                reader.close();
                content.close();

        // Result is an array of tweets
        final JSONArray arr = (JSONArray) new JSONTokener(builder.toString()).nextValue();

        final ArrayList<String[]> tweets = new ArrayList<>();

        // Need to grok dates of form "created_at": "Thu, 15 Nov 2012 18:27:17 +0000"
        final SimpleDateFormat dateFormat = new SimpleDateFormat("EEE MMM dd HH:mm:ss ZZZZZ yyyy");
        dateFormat.setLenient(true);

        for (int i = 0; i < arr.length(); i++) {
          final String text = arr.getJSONObject(i).get("text").toString();
          String tweettime = arr.getJSONObject(i).get("created_at").toString();

          // Extract & reformat the date
          Date created;
          final GregorianCalendar cal = new GregorianCalendar();
          try {
            created = dateFormat.parse(tweettime);
            cal.setTime(created);
            String day, mon;

                        day = cal.getDisplayName(Calendar.DAY_OF_WEEK, Calendar.LONG, Locale.getDefault());
                        mon = cal.getDisplayName(Calendar.MONTH, Calendar.SHORT, Locale.getDefault());

            tweettime = String.format("%s %02d:%02d - %s %d", day, cal.get(Calendar.HOUR_OF_DAY),
                cal.get(Calendar.MINUTE), mon, cal.get(Calendar.DAY_OF_MONTH));

          } catch (final Exception e) {
            Log.d(TAG, "Exception: " + e.getMessage() + ", parsing tweet date `" + tweettime + "'");
            tweettime = "--:--";
          }

          tweets.add(new String[] { tweettime, text });
        }

        return tweets;

      } else {
        Log.d(TAG, "Failed to download twitter info");
      }
    } catch (final ClientProtocolException e) {
      Log.d(TAG, "ClientProtocolException: " + e.getMessage() + ", Failed to download twitter info");
    } catch (final IOException e) {
      Log.d(TAG, "IOException: " + e.getMessage() + ", Failed to download twitter info");
    } catch (final Exception e) {
      Log.d(TAG, "Exception: " + e.getMessage() + ", Failed to download twitter info");
    }

    return null;
  }
}
Java Source Code List
