How to implement C2DM in android?

I am searching about how to send notification using C2DM. I found something and using that I am able to generate Registration Key as well as an Authentication Key.

But after that in ServerSimulator class (sever side code) I got 401 Error (401 Unauthorized).Now I passed Username and Password manually, which I synchronized in my Android device. I get same error as before.

I face this problem when I click on send message button..

I am stuck on this query. Has anyone managed to do this?

public class ServerSimulator extends Activity 
{
    private SharedPreferences prefManager;
    private final static String AUTH = "authentication";

    private static final String UPDATE_CLIENT_AUTH = "Update-Client-Auth";

    public static final String PARAM_REGISTRATION_ID = "registration_id";

    public static final S开发者_运维问答tring PARAM_DELAY_WHILE_IDLE = "delay_while_idle";

    public static final String PARAM_COLLAPSE_KEY = "collapse_key";

    private static final String UTF8 = "UTF-8";

    // Registration is currently hardcoded
    private final static String YOUR_REGISTRATION_STRING = "APA91bFkxmtIj5XiBU-Cze64s0gXNb7OmiWWZg-qLKibpLsVXaWq1X7hoRV9Ld9COYXirZAgkYegZBdBfUGt3lgtuhNJopvHB0KJ5ZyJ6Kt_HYRrZhgdJ1Y";

    private SharedPreferences prefs;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        prefManager = PreferenceManager.getDefaultSharedPreferences(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.mymenu, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.menuitem_user:
            Intent intent = new Intent(this, UserPreferences.class);
            startActivity(intent);
            break;
        default:
            break;
        }
        return false;
    }

    public void getAuthentification(View view) {
        SharedPreferences prefs = PreferenceManager
                .getDefaultSharedPreferences(this);

        HttpClient client = new DefaultHttpClient();
        HttpPost post = new HttpPost(
                "https://www.google.com/accounts/ClientLogin");

        try {

            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
            nameValuePairs.add(new BasicNameValuePair("Email","myEmail id")));
            nameValuePairs.add(new BasicNameValuePair("Passwd","my password")));
            nameValuePairs.add(new BasicNameValuePair("accountType", "GOOGLE"));
            nameValuePairs.add(new BasicNameValuePair("source","Google-cURL-Example"));
            nameValuePairs.add(new BasicNameValuePair("service", "ac2dm"));

            post.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            HttpResponse response = client.execute(post);
            BufferedReader rd = new BufferedReader(new InputStreamReader(
                    response.getEntity().getContent()));

            String line = "";
            while ((line = rd.readLine()) != null) {
                Log.e("HttpResponse", line);
                if (line.startsWith("Auth=")) {
                    Editor edit = prefManager.edit();
                    edit.putString(AUTH, line.substring(5));
                    edit.commit();
                    String s = prefManager.getString(AUTH, "n/a");
                    Toast.makeText(this, s, Toast.LENGTH_LONG).show();
                }

            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void showAuthentification(View view) {
        String s = prefManager.getString(AUTH, "n/a");
        Toast.makeText(this, s, Toast.LENGTH_LONG).show();
    }

    public void sendMessage(View view) {
        try {
            Log.e("Tag", "Started");
            String auth_key = prefManager.getString(AUTH, "n/a");
            // Send a sync message to this Android device.
            StringBuilder postDataBuilder = new StringBuilder();
            postDataBuilder.append(PARAM_REGISTRATION_ID).append("=")
                    .append(YOUR_REGISTRATION_STRING);

            // if (delayWhileIdle) {
            // postDataBuilder.append("&").append(PARAM_DELAY_WHILE_IDLE)
            // .append("=1");
            // }
            postDataBuilder.append("&").append(PARAM_COLLAPSE_KEY).append("=")
                    .append("0");

            postDataBuilder.append("&").append("data.payload").append("=")
                    .append(URLEncoder.encode("Lars war hier", UTF8));

            byte[] postData = postDataBuilder.toString().getBytes(UTF8);

            // Hit the dm URL.

            URL url = new URL("https://android.clients.google.com/c2dm/send");

            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setDoOutput(true);
            conn.setUseCaches(false);
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Content-Type",
                    "application/x-www-form-urlencoded;charset=UTF-8");
            conn.setRequestProperty("Content-Length",
                    Integer.toString(postData.length));
            conn.setRequestProperty("Authorization", "GoogleLogin auth="
                    + auth_key);

            OutputStream out = conn.getOutputStream();
            out.write(postData);
            out.close();

            int responseCode = conn.getResponseCode();

            Log.e("Tag", String.valueOf(responseCode));
            // Validate the response code

            if (responseCode == 401 || responseCode == 403) {
                // The token is too old - return false to retry later, will
                // fetch the token
                // from DB. This happens if the password is changed or token
                // expires. Either admin
                // is updating the token, or Update-Client-Auth was received by
                // another server,
                // and next retry will get the good one from database.
                Log.e("C2DM", "Unauthorized - need token");
            }

            // Check for updated token header
            String updatedAuthToken = conn.getHeaderField(UPDATE_CLIENT_AUTH);
            if (updatedAuthToken != null && !auth_key.equals(updatedAuthToken)) {
                Log.i("C2DM",
                        "Got updated auth token from datamessaging servers: "
                                + updatedAuthToken);
                Editor edit = prefManager.edit();
                edit.putString(AUTH, updatedAuthToken);
            }

            String responseLine = new BufferedReader(new InputStreamReader(
                    conn.getInputStream())).readLine();

            // NOTE: You *MUST* use exponential backoff if you receive a 503
            // response code.
            // Since App Engine's task queue mechanism automatically does this
            // for tasks that
            // return non-success error codes, this is not explicitly
            // implemented here.
            // If we weren't using App Engine, we'd need to manually implement
            // this.
            if (responseLine == null || responseLine.equals("")) {
                Log.i("C2DM", "Got " + responseCode
                        + " response from Google AC2DM endpoint.");
                throw new IOException(
                        "Got empty response from Google AC2DM endpoint.");
            }

            String[] responseParts = responseLine.split("=", 2);
            if (responseParts.length != 2) {
                Log.e("C2DM", "Invalid message from google: " + responseCode
                        + " " + responseLine);
                throw new IOException("Invalid response from Google "
                        + responseCode + " " + responseLine);
            }

            if (responseParts[0].equals("id")) {
                Log.i("Tag", "Successfully sent data message to device: "
                        + responseLine);
            }

            if (responseParts[0].equals("Error")) {
                String err = responseParts[1];
                Log.w("C2DM",
                        "Got error response from Google datamessaging endpoint: "
                                + err);
                // No retry.
                throw new IOException(err);
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

---

You are currently implementing C2DM in an older way. The way you are doing offers a lot of customizability, but not many people need that kind of customizability. With the new Google Plugin 2.4 Beta they have actually started integrating it all in, and it's pretty nice.

I'd highly recommend you watch the Google IO Android + AppEngine. They show how to integrate Android, AppEngine, and C2DM together really really simply. You can create something they call an "AppEngine Connected Android Project". So instead of making a ServerSimulator, you'd be actually working with a real server that can all be setup for free.

http://www.youtube.com/watch?v=M7SxNNC429U

If you wanted to move to another server, you'd have to re-write the server-side code, and then just change the URL that it's posting to. Pretty simple. I'd highly recommend checking out this example and working with the stock code, as it gives you something working right off the bat to play with:

FYI, there is currently a bug in the code (as it is in beta atm) when it comes to registering to a real hosted appengine server (everything works fine locally). It tries to send an expired registration token. I've been in contact with the google developers and they provided a fix for me. Let me know if you get to the point where you need it.