Android Open Source - android-http Http Service Assister Example Activity

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License

The source code is released under:

Apache License

Java Source Code

package at.diamonddogs.example.http.activity;
/*from w ww  .  j av  a 2 s  .  c  o  m*/
import java.util.List;
import java.util.Map;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import android.app.Activity;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import at.diamonddogs.data.dataobjects.WebRequest;
import at.diamonddogs.data.dataobjects.WebRequest.Type;
import at.diamonddogs.example.http.R;
import at.diamonddogs.example.http.dataobject.Weather;
import at.diamonddogs.example.http.processor.WeatherProcessor;
import at.diamonddogs.service.net.HttpService.WebRequestReturnContainer;
import at.diamonddogs.service.net.HttpServiceAssister;
import at.diamonddogs.service.processor.HeadRequestProcessor;
import at.diamonddogs.service.processor.ImageProcessor;
import at.diamonddogs.service.processor.ImageProcessor.ImageProcessHandler;
import at.diamonddogs.service.processor.ServiceProcessorMessageUtil;

/**
 * {@link HttpServiceAssisterExampleActivity} illustrates the use of the
 * {@link HttpServiceAssister}
 */
public class HttpServiceAssisterExampleActivity extends Activity {

  private static final Logger LOGGER = LoggerFactory.getLogger(HttpServiceAssisterExampleActivity.class.getSimpleName());

  private HttpServiceAssister assister;

  /**
   * Text view to display a weather string
   */
  private TextView text;

  /**
   * Text view to display the temperature
   */
  private TextView temperature;

  /**
   * The weather image
   */
  private ImageView image;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.httpserviceassisterexampleactivity);
    assister = new HttpServiceAssister(this);
    text = (TextView) findViewById(R.id.httpserviceassisterexampleactivity_text);
    temperature = (TextView) findViewById(R.id.httpserviceassisterexampleactivity_temperature);
    image = (ImageView) findViewById(R.id.httpserviceassisterexampleactivity_image);
  }

  /**
   * {@inheritDoc}
   */

  @Override
  protected void onResume() {
    super.onResume();
    assister.bindService();
    String weatherUrl = getWeatherUrl("Austria", "Vienna");
    LOGGER.info("URL: " + weatherUrl);

    // we can start WebRequests without having to wait for service
    // binding.
    // HttpServiceAssister will queue asynchronous WebRequests and
    // execute
    // them once a connection has been established. The ServiceProcessor
    // will automatically be registered as well.

    // --- SYNC WEB REQUEST

    // Synchronous WebRequest cannot be executed on the Main (UI) thread
    // using HttpServiceAssister (technical limitation). The actual request
    // will still block the current thread though!
    new ExampleAsyncTask().execute(weatherUrl);

    // RESETTING THE ASSISTER FOR DEMONSTRATION PURPOSES! REBINDING THE
    // SERVICE
    assister.unbindService();
    assister = new HttpServiceAssister(this);
    assister.bindService();

    // --- ASYNC WEB REQUEST

    WebRequest asyncRequest = new WebRequest();
    // takes a String or URL object!
    asyncRequest.setUrl(weatherUrl);

    // The processorid tells HttpService what to do once a web reply has
    // been received.
    // You MUST set a processor id and the processor needs to be registered
    // with HttpService.
    // You may use DummyProcessor.ID to circumvent processor implementation
    asyncRequest.setProcessorId(WeatherProcessor.ID);

    // run the web request, WeatherHandler will receive a callback once the
    // web request has been finished. This call is alway possible, if the
    // HttpService is not bound yet, the WebRequest will be appended to a
    // queue and processed when HttpService becomes available
    assister.runWebRequest(new WeatherHandler(), asyncRequest, new WeatherProcessor());
  }

  /**
   * {@inheritDoc}
   */
  @Override
  protected void onPause() {
    super.onPause();
    assister.unbindService();
  }

  /**
   * Formats the openweathermap.org weather URL
   * 
   * @param country
   *            the country
   * @param city
   *            the city
   * @return the weather url for country & city
   */
  private String getWeatherUrl(String country, String city) {
    Uri u = Uri.parse("http://api.openweathermap.org/data/2.5/weather/");
    // @formatter:off
    u = u.buildUpon()
      .appendQueryParameter("q", city + "," + country)
      .appendQueryParameter("units", "metric")
    .build();
    // @formatter:on
    return u.toString();
  }

  /**
   * Runs an Image {@link WebRequest} and displays the image on a given
   * {@link ImageView}
   * 
   * @param w
   *            a {@link Weather} object
   */
  private void runImageRequest(Weather w) {
    String imageUrl = "http://openweathermap.org/img/w/" + w.getIcon() + ".png";

    // use this helper method to obtain a valid image WebRequest
    WebRequest imageRequest = ImageProcessor.getDefaultImageRequest(imageUrl);

    // ImageProcessHanlder will take care of displaying the image, no
    // additional work required!
    assister.runWebRequest(new ImageProcessHandler(image, imageUrl), imageRequest, new ImageProcessor());
  }

  /**
   * This implementation of {@link AsyncTask} is used to execute a synchronous
   * HEAD {@link WebRequest}. As in {@link HttpExampleActivity}, the headers
   * will be logged and not displayed on the UI.
   */
  private final class ExampleAsyncTask extends AsyncTask<String, Integer, Object> {

    /**
     * {@inheritDoc}
     */
    @Override
    protected Object doInBackground(String... params) {
      WebRequest syncWebRequest = new WebRequest();
      syncWebRequest.setUrl(params[0]);
      syncWebRequest.setRequestType(Type.HEAD);

      // default header request processor
      syncWebRequest.setProcessorId(HeadRequestProcessor.ID);

      return assister.runSynchronousWebRequest(syncWebRequest, new HeadRequestProcessor());
    }

    /**
     * {@inheritDoc}
     */
    @SuppressWarnings("unchecked")
    @Override
    protected void onPostExecute(Object result) {
      Map<String, List<String>> headers = (Map<String, List<String>>) ((WebRequestReturnContainer) result).getPayload();
      if (headers != null) {
        for (String key : headers.keySet()) {
          LOGGER.error("KEY -> " + key);
          for (String value : headers.get(key)) {
            LOGGER.error("    VALUE -> " + value);
          }
        }
      } else {
        Toast.makeText(HttpServiceAssisterExampleActivity.this, "Error while optaining headers", Toast.LENGTH_SHORT).show();
      }
    }
  }

  /**
   * This handler receives a callback once the web request has been processed.
   */
  private class WeatherHandler extends Handler {
    /**
     * {@inheritDoc}
     */
    @Override
    public void handleMessage(Message msg) {
      super.handleMessage(msg);
      if (ServiceProcessorMessageUtil.isFromProcessor(msg, WeatherProcessor.ID)) {
        if (ServiceProcessorMessageUtil.isSuccessful(msg)) {
          Weather w = (Weather) msg.obj;
          text.setText(w.getText());
          temperature.setText(String.valueOf(w.getTemperature()));

          runImageRequest(w);
        } else {
          Toast.makeText(HttpServiceAssisterExampleActivity.this, "Error fetching weather", Toast.LENGTH_LONG).show();
        }
      }

    }
  }

}

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