programacion - Cómo implementar un GCM Hello World para Android con Android Studio

manual de programacion android pdf

Question

Llevo unos días buscando cómo implementar Google Cloud Messaging para Android, pero tengo serias dudas al respecto.

Quiero decir, aparentemente Google puso algunas buenas informaciones en línea, como here y here , pero estoy confundido acerca de toda la lógica. Una página habla sobre el lado del cliente y otra sobre el lado del servidor. Genial, pero ¿cómo puedo unirlo todo? ¿Cómo implemento el protocolo HTTP y / o XMPP para comunicarme con los servidores de conexión GCM?

Me gustaría implementar un HelloWorld básico para GCM, que funcionaría con los siguientes pasos:

1. App send a message (say "HelloWorld") to GCM;
2. Receive that message from GCM and add it to a TextView.

¿Cuáles son los pasos necesarios para lograr esta aplicación básica?

Gracias,

Answer 1

Si ha leído los dos enlaces en su pregunta y ha entendido los conceptos clave de GCM, puede consultar los siguientes códigos de muestra:

Por supuesto, supongamos que has terminado:

• Cree un proyecto y su clave API de servidor en Google Developers Console
• Establezca permisos en sus archivos de AndroidManifest como este <uses-permission android:name="android.permission.INTERNET" />

Lado del servidor:

public class MainActivity extends AppCompatActivity {
private TextView mTextView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextView = (TextView) findViewById(R.id.textView);
new GCMRequest().execute();
}
...
private class GCMRequest extends AsyncTask<Void, Void, String> {
@Override
protected String doInBackground(Void... voids) {
final String API_KEY = "..."; // An API key saved on the app server that gives the app server authorized access to Google services
final String CLIENT_REG_ID = "..."; //An ID issued by the GCM connection servers to the client app that allows it to receive messages
final String postData = "{ /"registration_ids/": [ /"" + CLIENT_REG_ID + "/" ], " +
"/"delay_while_idle/": true, " +
"/"data/": {/"tickerText/":/"My Ticket/", " +
"/"contentTitle/":/"My Title/", " +
"/"message/": /"Test GCM message from GCMServer-Android/"}}";
try {
URL url = new URL("https://android.googleapis.com/gcm/send");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setDoInput(true);
urlConnection.setDoOutput(true);
urlConnection.setRequestMethod("POST");
urlConnection.setRequestProperty("Content-Type", "application/json");
urlConnection.setRequestProperty("Authorization", "key=" + API_KEY);
OutputStream outputStream = new BufferedOutputStream(urlConnection.getOutputStream());
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream, "utf-8"));
writer.write(postData);
writer.flush();
writer.close();
outputStream.close();
int responseCode = urlConnection.getResponseCode();
InputStream inputStream;
if (responseCode < HttpURLConnection.HTTP_BAD_REQUEST) {
inputStream = urlConnection.getInputStream();
} else {
inputStream = urlConnection.getErrorStream();
}
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String temp, response = "";
while ((temp = bufferedReader.readLine()) != null) {
response += temp;
}
return response;
} catch (IOException e) {
e.printStackTrace();
return e.toString();
}
}
@Override
protected void onPostExecute(String message) {
super.onPostExecute(message);
if (mTextView != null) {
try {
JSONObject jsonObject = new JSONObject(message);
mTextView.setText(jsonObject.toString(5));
} catch (JSONException e) {
e.printStackTrace();
mTextView.setText(e.toString());
}
}
}
}
}

Lado del cliente:

MainActivity.java:

public class MainActivity extends AppCompatActivity {
private final Context mContext = this;
private final String SENDER_ID = "..."; // Project Number at https://console.developers.google.com/project/...
private final String SHARD_PREF = "com.example.gcmclient_preferences";
private final String GCM_TOKEN = "gcmtoken";
public static TextView mTextView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SharedPreferences appPrefs = mContext.getSharedPreferences(SHARD_PREF, Context.MODE_PRIVATE);
String token = appPrefs.getString(GCM_TOKEN, "");
if (token.isEmpty()) {
try {
getGCMToken();
} catch (Exception e) {
e.printStackTrace();
}
}
mTextView = (TextView) findViewById(R.id.textView);
}
...
private void getGCMToken() {
new AsyncTask<Void, Void, Void>() {
@Override
protected Void doInBackground(Void... params) {
try {
InstanceID instanceID = InstanceID.getInstance(mContext);
String token = instanceID.getToken(SENDER_ID, GoogleCloudMessaging.INSTANCE_ID_SCOPE, null);
if (token != null && !token.isEmpty()) {
SharedPreferences appPrefs = mContext.getSharedPreferences(SHARD_PREF, Context.MODE_PRIVATE);
SharedPreferences.Editor prefsEditor = appPrefs.edit();
prefsEditor.putString(GCM_TOKEN, token);
prefsEditor.apply();
}
Log.i("GCM", token);
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}.execute();
}
}

GcmService.java:

public class GcmService extends GcmListenerService {
@Override
public void onMessageReceived(String from, Bundle data) {
JSONObject jsonObject = new JSONObject();
Set<String> keys = data.keySet();
for (String key : keys) {
try {
jsonObject.put(key, data.get(key));
} catch (JSONException e) {
e.printStackTrace();
}
}
try {
sendNotification("Received: " + jsonObject.toString(5));
} catch (JSONException e) {
e.printStackTrace();
}
}
@Override
public void onDeletedMessages() {
sendNotification("Deleted messages on server");
}
@Override
public void onMessageSent(String msgId) {
sendNotification("Upstream message sent. Id=" + msgId);
}
@Override
public void onSendError(String msgId, String error) {
sendNotification("Upstream message send error. Id=" + msgId + ", error" + error);
}
private void sendNotification(final String msg) {
Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable() {
@Override
public void run() {
if (MainActivity.mTextView != null) {
MainActivity.mTextView.setText(msg);
}
}
});
}
}

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.gcmandroid" >
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<permission android:name="com.example.gcm.permission.C2D_MESSAGE"
android:protectionLevel="signature" />
<uses-permission android:name="com.example.gcm.permission.C2D_MESSAGE" />
<application
android:allowBackup="true"
android:fullBackupContent="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<receiver
android:name="com.google.android.gms.gcm.GcmReceiver"
android:exported="true"
android:permission="com.google.android.c2dm.permission.SEND" >
<intent-filter>
<action android:name="com.google.android.c2dm.intent.REGISTRATION" />
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
<category android:name="com.example.gcm" />
</intent-filter>
</receiver>
<service android:name=".GcmService" android:exported="false">
<intent-filter>
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
</intent-filter>
</service>
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>