Android Open Source - coursera-android-001 Place Downloader Task

• Back to App/system  ↑

From Project

Back to project page coursera-android-001.

License

The source code is released under:

MIT License

Java Source Code

package course.labs.contentproviderlab;
//from   w  ww .j av a  2s . c  om
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.StringReader;
import java.lang.ref.WeakReference;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.DOMException;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.location.Location;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.util.Log;

public class PlaceDownloaderTask extends AsyncTask<Location, Void, PlaceRecord> {

  // Change to false if you don't have network access
  private static final boolean HAS_NETWORK = true;

  // TODO - put your www.geonames.org account name here.
  private static String USERNAME = "dutchovens";

  private HttpURLConnection mHttpUrl;
  private WeakReference<PlaceViewActivity> mParent;
  private static Bitmap mStubBitmap;
  private static Location mockLoc1 = new Location(
      LocationManager.NETWORK_PROVIDER);
  private static Location mockLoc2 = new Location(
      LocationManager.NETWORK_PROVIDER);

  public PlaceDownloaderTask(PlaceViewActivity parent) {
    super();
    mParent = new WeakReference<PlaceViewActivity>(parent);

    if (!HAS_NETWORK) {
      mStubBitmap = BitmapFactory.decodeResource(parent.getResources(),
          R.drawable.stub);
      mockLoc1.setLatitude(37.422);
      mockLoc1.setLongitude(-122.084);
      mockLoc2.setLatitude(38.996667);
      mockLoc2.setLongitude(-76.9275);
    }
  }

  @Override
  protected PlaceRecord doInBackground(Location... location) {

    PlaceRecord place = null;

    if (HAS_NETWORK) {

      place = getPlaceFromURL(generateURL(USERNAME, location[0]));

      if ("" != place.getCountryName()) {
        place.setLocation(location[0]);
        place.setFlagBitmap(getFlagFromURL(place.getFlagUrl()));
      } else {
        place = null;
      }
    } else {
      place = new PlaceRecord(location[0]);
      if (location[0].distanceTo(mockLoc1) < 100) {
        place.setCountryName("United States");
        place.setPlace("The Greenhouse");
        place.setFlagBitmap(mStubBitmap);
                place.setFlagUrl("stub.jpg");
      } else {
        place.setCountryName("United States");
        place.setPlace("Berwyn");
        place.setFlagBitmap(mStubBitmap);
                place.setFlagUrl("stub.jpg");
      }
    }

    return place;

  }

  @Override
  protected void onPostExecute(PlaceRecord result) {

    if (null != result && null != mParent.get()) {
      mParent.get().addNewPlace(result);
    }
  }

  private PlaceRecord getPlaceFromURL(String... params) {
    String result = null;
    BufferedReader in = null;

    try {
      URL url = new URL(params[0]);
      mHttpUrl = (HttpURLConnection) url.openConnection();
      in = new BufferedReader(new InputStreamReader(
          mHttpUrl.getInputStream()));

      StringBuffer sb = new StringBuffer("");
      String line = "";
      while ((line = in.readLine()) != null) {
        sb.append(line + "\n");
      }
      result = sb.toString();

    } catch (MalformedURLException e) {

    } catch (IOException e) {

    } finally {
      try {
        if (null != in) {
          in.close();
        }
      } catch (IOException e) {
        e.printStackTrace();
      }
      mHttpUrl.disconnect();
    }

    return placeDataFromXml(result);
  }

  private Bitmap getFlagFromURL(String flagUrl) {

    InputStream in = null;

    try {
      URL url = new URL(flagUrl);
      mHttpUrl = (HttpURLConnection) url.openConnection();
      in = mHttpUrl.getInputStream();

      return BitmapFactory.decodeStream(in);

    } catch (MalformedURLException e) {
      Log.e("DEBUG", e.toString());
    } catch (IOException e) {
      Log.e("DEBUG", e.toString());
    } finally {
      try {
        if (null != in) {
          in.close();
        }
      } catch (IOException e) {
        e.printStackTrace();
      }
      mHttpUrl.disconnect();
    }

    return BitmapFactory.decodeResource(mParent.get().getResources(),
        R.drawable.stub);
  }

  private static PlaceRecord placeDataFromXml(String xmlString) {
    DocumentBuilder builder;
    String countryName = "";
    String countryCode = "";
    String placeName = "";

    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

    try {
      builder = factory.newDocumentBuilder();
      Document document = builder.parse(new InputSource(new StringReader(
          xmlString)));
      NodeList list = document.getDocumentElement().getChildNodes();
      for (int i = 0; i < list.getLength(); i++) {
        Node curr = list.item(i);

        NodeList list2 = curr.getChildNodes();

        for (int j = 0; j < list2.getLength(); j++) {

          Node curr2 = list2.item(j);
          if (curr2.getNodeName() != null) {

            if (curr2.getNodeName().equals("countryName")) {
              countryName = curr2.getTextContent();
            } else if (curr2.getNodeName().equals("countryCode")) {
              countryCode = curr2.getTextContent();
            } else if (curr2.getNodeName().equals("name")) {
              placeName = curr2.getTextContent();
            }
          }
        }
      }
    } catch (DOMException e) {
      e.printStackTrace();
    } catch (ParserConfigurationException e) {
      e.printStackTrace();
    } catch (SAXException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }

    return new PlaceRecord(generateFlagURL(countryCode.toLowerCase()),
        null, countryName, placeName, -1, -1);
  }

  private static String generateURL(String username, Location location) {

    return "http://www.geonames.org/findNearbyPlaceName?username="
        + username + "&style=full&lat=" + location.getLatitude()
        + "&lng=" + location.getLongitude();
  }

  private static String generateFlagURL(String countryCode) {
    return "http://www.geonames.org/flags/x/" + countryCode + ".gif";
  }

}

Java Source Code List

• Back to App/system  ↑