如何使用Firebase Messaging发送一对一消息

Question

我一直在尝试阅读有关如何将消息从一个设备发送到另一个设备的官方文档和指南.我已经在实时数据库中保存了两个设备的注册令牌,因此我有另一个设备的注册令牌.我尝试了以下方式发送消息

RemoteMessage message = new RemoteMessage.Builder(getRegistrationToken())
                    .setMessageId(incrementIdAndGet())
                    .addData("message", "Hello")
                    .build();
FirebaseMessaging.getInstance().send(message);

但这不起作用.其他设备不接收任何消息.我甚至不确定,如果我可以使用上游消息发送来进行设备到设备的通信.

PS:我只是想知道使用FCM是否可以实现设备到设备的消息传递？如果是,那么我使用的代码是否有问题？如果是,那么正确的方法是什么.

更新:
我的问题是询问设备到设备的消息传递而不使用除firebase之外的任何单独的服务器是否可以进行消息传递是否可能,如果是,那么,因为没有关于它的文档.我不明白这里要解释什么？无论如何我得到了答案,并在问题重新开始后将其更新为答案.

Answer 1

Firebase有两个功能可以向设备发送消息:

• Firebase控制台中的"通知"面板允许您向特定设备,用户组或用户订阅的主题发送通知.
• 通过调用Firebase云消息传递API,您可以使用您喜欢的任何定位策略发送消息.调用FCM API需要访问您的服务器密钥,您不应在客户端设备上公开该密钥.这就是为什么你应该总是在应用服务器上运行这样的代码.

在火力地堡文档显示了这种视觉:

Firebase云消息传递不支持将消息从一个设备直接发送到另一个设备.

更新:我写了一篇博文,详细介绍了如何使用Firebase数据库,云消息传递和Node.js在Android设备之间发送通知.

更新2:您现在还可以使用Cloud Functions for Firebase安全地发送邮件,而无需启动服务器.请参阅此示例用例以开始使用.

Answer 2

警告 我们在任何地方都没有提到这种方法,这是一个非常重要的原因.这会在您放在每个客户端设备上的APK中公开您的服务器密钥.它可以(并因此将)从那里获取并可能导致滥用您的项目.我强烈建议不要采用这种方法,除了您只放在自己设备上的应用程序.- 弗兰克范普弗伦

好的,所以Frank的答案是正确的,Firebase本身不支持设备到设备的消息传递.然而,那里有一个漏洞.Firebase服务器无法识别您是从实际服务器发送请求还是从设备执行此操作.

因此,所有你需要做的就是发送Post Request到Firebase与服务器密钥一起的邮件服务器.请记住,服务器密钥不应该在设备上,但如果您希望使用Firebase Messaging进行设备到设备的消息传递,则没有其他选择.

我使用OkHTTP而不是默认方式调用Rest API.代码是这样的 -

public static final String FCM_MESSAGE_URL = "https://fcm.googleapis.com/fcm/send";
OkHttpClient mClient = new OkHttpClient();
public void sendMessage(final JSONArray recipients, final String title, final String body, final String icon, final String message) {

        new AsyncTask<String, String, String>() {
            @Override
            protected String doInBackground(String... params) {
                try {
                    JSONObject root = new JSONObject();
                    JSONObject notification = new JSONObject();
                    notification.put("body", body);
                    notification.put("title", title);
                    notification.put("icon", icon);

                    JSONObject data = new JSONObject();
                    data.put("message", message);
                    root.put("notification", notification);
                    root.put("data", data);
                    root.put("registration_ids", recipients);

                    String result = postToFCM(root.toString());
                    Log.d(TAG, "Result: " + result);
                    return result;
                } catch (Exception ex) {
                    ex.printStackTrace();
                }
                return null;
            }

            @Override
            protected void onPostExecute(String result) {
                try {
                    JSONObject resultJson = new JSONObject(result);
                    int success, failure;
                    success = resultJson.getInt("success");
                    failure = resultJson.getInt("failure");
                    Toast.makeText(getCurrentActivity(), "Message Success: " + success + "Message Failed: " + failure, Toast.LENGTH_LONG).show();
                } catch (JSONException e) {
                    e.printStackTrace();
                    Toast.makeText(getCurrentActivity(), "Message Failed, Unknown error occurred.", Toast.LENGTH_LONG).show();
                }
            }
        }.execute();
    }

String postToFCM(String bodyString) throws IOException {
        RequestBody body = RequestBody.create(JSON, bodyString);
        Request request = new Request.Builder()
                .url(FCM_MESSAGE_URL)
                .post(body)
                .addHeader("Authorization", "key=" + SERVER_KEY)
                .build();
        Response response = mClient.newCall(request).execute();
        return response.body().string();
    }

我希望Firebase将来会有更好的解决方案.但到那时,我认为这是唯一的方法.另一种方式是发送主题消息或组消息.但这不属于问题的范围.

更新:
JSONArray定义如下 -

JSONArray regArray = new JSONArray(regIds);

regIds是一个注册ID的String数组,您要发送此消息.请记住,即使您希望将注册ID发送给单个收件人,注册ID也必须始终位于数组中.

Answer 3

我还在我的原型中使用了直接设备到设备的 gcm 消息传递。它一直运作良好。我们没有任何服务器。我们使用短信/文本交换 GCM 注册 ID，然后使用 GCM 进行通信。我在这里放置与 GCM 处理相关的代码

**************发送 GCM 消息************

//Sends gcm message Asynchronously
public class GCM_Sender extends IntentService{
    final String API_KEY = "****************************************";

    //Empty constructor
    public GCM_Sender() {
        super("GCM_Sender");
    }

    //Processes gcm send messages
    @Override
    protected void onHandleIntent(Intent intent) {  

        Log.d("Action Service", "GCM_Sender Service Started");
        //Get message from intent
        String msg = intent.getStringExtra("msg");
        msg =  "\"" + msg + "\"";
        try{
            String ControllerRegistrationId = null;                 
            //Check registration id in db       
            if(RegistrationIdAdapter.getInstance(getApplicationContext()).getRegIds().size() > 0 ) {
                String controllerRegIdArray[] = RegistrationIdAdapter.getInstance(getApplicationContext()).getRegIds().get(1);
                if(controllerRegIdArray.length>0)
                    ControllerRegistrationId = controllerRegIdArray[controllerRegIdArray.length-1];

                if(!ControllerRegistrationId.equalsIgnoreCase("NULL")){
                    // 1. URL
                    URL url = new URL("https://android.googleapis.com/gcm/send");
                    // 2. Open connection
                    HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
                    // 3. Specify POST method
                    urlConnection.setRequestMethod("POST");
                    // 4. Set the headers
                    urlConnection.setRequestProperty("Content-Type", "application/json");
                    urlConnection.setRequestProperty("Authorization", "key=" + API_KEY);
                    urlConnection.setDoOutput(true);
                    // 5. Add JSON data into POST request body
                    JSONObject obj = new JSONObject("{\"time_to_live\": 0,\"delay_while_idle\": true,\"data\":{\"message\":" + msg + "},\"registration_ids\":[" + ControllerRegistrationId + "]}");
                    // 6. Get connection output stream
                    OutputStreamWriter out = new OutputStreamWriter(urlConnection.getOutputStream());
                    out.write(obj.toString());
                    out.close();
                    // 6. Get the response
                    int responseCode = urlConnection.getResponseCode();

                    BufferedReader in = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
                    String inputLine;
                    StringBuffer response = new StringBuffer();
                    while ((inputLine = in.readLine()) != null){
                        response.append(inputLine);
                    }
                    in.close();
                    Log.d("GCM getResponseCode:", new Integer(responseCode).toString());
                }else{
                    Log.d("GCM_Sender:","Field REGISTRATION_TABLE is null");
                }
            }else {
                Log.d("GCM_Sender:","There is no Registration ID in DB ,please sync devices");
            }
        } catch (Exception e) {
            e.printStackTrace();
            //MessageSender.getInstance().sendMessage(msg, Commands.SMS_MESSAGE);
        } 
    }

    //Called when service is no longer alive
    @Override
    public void onDestroy() {
        super.onDestroy();
        //Do a log that GCM_Sender service has been destroyed
        Log.d("Action Service", "GCM_Sender Service Destroyed");
    }
}

**************接收 GCM 消息************

public class GCM_Receiver extends WakefulBroadcastReceiver {
    public static final String RETRY_ACTION ="com.google.android.c2dm.intent.RETRY";
    public static final String REGISTRATION ="com.google.android.c2dm.intent.REGISTRATION";
    public SharedPreferences preferences;

    //Processes Gcm message .
    @Override
    public void onReceive(Context context, Intent intent) {
        ComponentName comp = new ComponentName(context.getPackageName(),
                GCMNotificationIntentService.class.getName());
        //Start GCMNotificationIntentService to handle gcm message asynchronously
        startWakefulService(context, (intent.setComponent(comp)));
        setResultCode(Activity.RESULT_OK);

        /*//Check if DatabaseService is running .
        if(!DatabaseService.isServiceRunning) {
            Intent dbService = new Intent(context,DatabaseService.class);
            context.startService(dbService);
        }*/
        //Check if action is RETRY_ACTION ,if it is then do gcm registration again .
        if(intent.getAction().equals(RETRY_ACTION)) {
            String registrationId = intent.getStringExtra("registration_id");

            if(TextUtils.isEmpty(registrationId)){
                DeviceRegistrar.getInstance().register(context);
            }else {
                //Save registration id to prefs .
                preferences = PreferenceManager.getDefaultSharedPreferences(context);
                SharedPreferences.Editor editor = preferences.edit();
                editor.putString("BLACKBOX_REG_ID",registrationId);
                editor.commit();
            }
        } else if (intent.getAction().equals(REGISTRATION)) {
        }

    }
}

//Processes gcm messages asynchronously .
public class GCMNotificationIntentService extends IntentService{
    public static final int NOTIFICATION_ID = 1;
    private NotificationManager mNotificationManager;
    String gcmData;
    private final String TAG = "GCMNotificationIntentService";

    //Constructor with super().
    public GCMNotificationIntentService() {
        super("GcmIntentService");
    }

    //Called when startService() is called by its Client .
    //Processes gcm messages .
    @Override
    protected void onHandleIntent(Intent intent) {

        Log.d("GCMNotificationIntentService", "GCMNotificationIntentService Started");
        Bundle extras = intent.getExtras();
        //Get instance of GoogleCloudMessaging .
        GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
        //Get gcm message type .
        String messageType = gcm.getMessageType(intent);

        if (!extras.isEmpty()) {
            if (GoogleCloudMessaging.MESSAGE_TYPE_SEND_ERROR
                    .equals(messageType)) {
                sendNotification("Send error: " + extras.toString());
            } else if (GoogleCloudMessaging.MESSAGE_TYPE_DELETED
                    .equals(messageType)) {
                sendNotification("Deleted messages on server: "
                        + extras.toString());
            } else if (GoogleCloudMessaging.MESSAGE_TYPE_MESSAGE
                    .equals(messageType)) {
                Log.i(TAG, "Completed work @ " + SystemClock.elapsedRealtime());

                gcmData = extras.getString("message");
                Intent actionService = new Intent(getApplicationContext(),Action.class);    
                actionService.putExtra("data", gcmData);
                //start Action service .
                startService(actionService);

                //Show push notification .
                sendNotification("Action: " + gcmData);
                //Process received gcmData.

                Log.d(TAG,"Received Gcm Message from Controller : " + extras.getString("message"));
            }
        }
        GCM_Receiver.completeWakefulIntent(intent);
    }

    //Shows notification on device notification bar .
    private void sendNotification(String msg) {
        mNotificationManager = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);
        Intent notificationIntent = new Intent(this, BlackboxStarter.class);
        //Clicking on GCM notification add new layer of app.
        notificationIntent.setFlags( Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
        PendingIntent contentIntent = PendingIntent.getActivity(this, 0,notificationIntent, PendingIntent.FLAG_CANCEL_CURRENT);
        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(
                this).setSmallIcon(R.drawable.gcm_cloud)
                .setContentTitle("Notification from Controller")
                .setStyle(new NotificationCompat.BigTextStyle().bigText(msg))
                .setContentText(msg);
        mBuilder.setContentIntent(contentIntent);
        mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
        //Play default notification
        try {
            Uri notification = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
            Ringtone r = RingtoneManager.getRingtone(getApplicationContext(), notification);
            r.play();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    //Called when service is no longer be available .
    @Override
    public void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        Log.d("GCMNotificationIntentService", "GCMNotificationIntentService Destroyed");
    }

}