Android Open Source - GestureMechanism Server Utilities

• Back to Development/gesture  ↑

From Project

Back to project page GestureMechanism.

License

The source code is released under:

GNU Lesser General Public License

Java Source Code

package com.in.mobile.notification.handler;
//  www  . ja  va2 s.c  o  m
import com.google.android.gcm.GCMRegistrar;
import com.in.mobile.common.utilities.Commons;

import android.content.Context;
import android.util.Log;

import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Random;

/**
 * Helper class used to communicate with the demo server.
 */
public final class ServerUtilities {

  private static final int MAX_ATTEMPTS = 5;
  private static final int BACKOFF_MILLI_SECONDS = 2000;
  private static final Random random = new Random();

  /**
   * Register this account/device pair within the server.
   * 
   * @return whether the registration succeeded or not.
   */
  public static boolean register(final Context context, final String regId) {

    String serverUrl = Commons.SERVER_URL + "/register";
    Map<String, String> params = new HashMap<String, String>();
    params.put("regId", regId);
    long backoff = BACKOFF_MILLI_SECONDS + random.nextInt(1000);
    // Once GCM returns a registration id, we need to register it in the
    // demo server. As the server might be down, we will retry it a couple
    // times.
    for (int i = 1; i <= MAX_ATTEMPTS; i++) {
      Log.d("ServerUtilities - register", "Attempt #" + i
          + " to register");
      try {

        post(serverUrl, params);
        GCMRegistrar.setRegisteredOnServer(context, true);
        String message = "Message1";
        Commons.displayMessage(context, message);
        return true;
      } catch (IOException e) {
        // Here we are simplifying and retrying on any error; in a real
        // application, it should retry only on unrecoverable errors
        // (like HTTP error code 503).
        Log.e("ServerUtilities - register",
            "Failed to register on attempt " + i + ". "
                + e.toString());
        if (i == MAX_ATTEMPTS) {
          break;
        }
        try {
          Log.d("ServerUtilities - register", "Sleeping for "
              + backoff + " ms before retry");
          Thread.sleep(backoff);
        } catch (InterruptedException e1) {
          // Activity finished before we complete - exit.
          Log.d("ServerUtilities - register",
              "Thread interrupted: abort remaining retries!");
          Thread.currentThread().interrupt();
          return false;
        }
        // increase backoff exponentially
        backoff *= 2;
      }
    }
    String message = "Message 2";
    Commons.displayMessage(context, message);
    return false;
  }

  /**
   * Unregister this account/device pair within the server.
   */
  public static void unregister(final Context context, final String regId) {
    Log.i(Commons.TAG, "unregistering device (regId = " + regId + ")");
    String serverUrl = Commons.SERVER_URL + "/unregister";
    Map<String, String> params = new HashMap<String, String>();
    params.put("regId", regId);
    try {
      post(serverUrl, params);
      GCMRegistrar.setRegisteredOnServer(context, false);
      String message = "Message 3";
      Commons.displayMessage(context, message);
    } catch (IOException e) {
      // At this point the device is unregistered from GCM, but still
      // registered in the server.
      // We could try to unregister again, but it is not necessary:
      // if the server tries to send a message to the device, it will get
      // a "NotRegistered" error message and should unregister the device.
      String message = "Message error";
      Commons.displayMessage(context, message);
    }
  }

  /**
   * Issue a POST request to the server.
   * 
   * @param endpoint
   *            POST address.
   * @param params
   *            request parameters.
   * 
   * @throws IOException
   *             propagated from POST.
   */
  private static void post(String endpoint, Map<String, String> params)
      throws IOException {
    URL url;
    try {
      url = new URL(endpoint);
    } catch (MalformedURLException e) {
      throw new IllegalArgumentException("invalid url: " + endpoint);
    }
    StringBuilder bodyBuilder = new StringBuilder();
    Iterator<Entry<String, String>> iterator = params.entrySet().iterator();
    // constructs the POST body using the parameters
    while (iterator.hasNext()) {
      Entry<String, String> param = iterator.next();
      bodyBuilder.append(param.getKey()).append('=')
          .append(param.getValue());
      if (iterator.hasNext()) {
        bodyBuilder.append('&');
      }
    }
    String body = bodyBuilder.toString();
    Log.v(Commons.TAG, "Posting '" + body + "' to " + url);
    byte[] bytes = body.getBytes();
    HttpURLConnection conn = null;
    try {
      conn = (HttpURLConnection) url.openConnection();
      conn.setDoOutput(true);
      conn.setUseCaches(false);
      conn.setFixedLengthStreamingMode(bytes.length);
      conn.setRequestMethod("POST");
      conn.setRequestProperty("Content-Type",
          "application/x-www-form-urlencoded;charset=UTF-8");
      // post the request
      OutputStream out = conn.getOutputStream();
      out.write(bytes);
      out.close();
      // handle the response
      int status = conn.getResponseCode();
      if (status != 200) {
        throw new IOException("Post failed with error code " + status);
      }
    } finally {
      if (conn != null) {
        conn.disconnect();
      }
    }
  }
}

Java Source Code List

• Back to Development/gesture  ↑