How to send device to device messages using Firebase Cloud Messaging?

Question

After searching the docs I could not find any info on how to send device to device messages using FCM without the use of an external server.

For example, if I was cr

Answer 1

Yes, it's possible to do it without any server. You can create a device group client side and then you exchange messages in the group. However there are limitations:

1. You have to use the same Google account on the devices
2. You can't send high priority messages

Reference: Firebase doc See the section "Managing device groups on Android client apps"

Answer 2

So I had an idea here. See: If the FCM, as well as the GCM, has a endpoit to http request where we can send a post json with our message data, including the token (s) of devices that we want this message to be delivered.

So why not send a post to Firebase server with this notification to be delivered to user B? you understand ?

So, you send the message and chat with a call post to ensure delivery of the notification if the user is with your app in the background. I am also in need of it soon, I will test later. What do you say about?

Answer 3

If you have fcm(gcm) token of the device to whom you want to send notification. It's just a post request to send the notification.

https://github.com/prashanthd/google-services/blob/master/android/gcm/gcmsender/src/main/java/gcm/play/android/samples/com/gcmsender/GcmSender.java

Answer 4

1) subscribe an identical topic name, for example:

• ClientA.subcribe("to/topic_users_channel")
• ClientB.subcribe("to/topic_users_channel")

2) send messages inside the application

GoogleFirebase : How-to send topic messages

Answer 5

You can do it using Volly Jsonobject request....

follow this Steps first:

1 copy legacy server key and store it as Legacy_SERVER_KEY

Legacy Server key

you can see in picture how to get

2 You need Volley dependency

compile 'com.mcxiaoke.volley:library:1.0.19'

Code for send Push:-

private void sendFCMPush() {

    String Legacy_SERVER_KEY = YOUR_Legacy_SERVER_KEY;
    String msg = "this is test message,.,,.,.";
    String title = "my title";
    String token = FCM_RECEIVER_TOKEN;

    JSONObject obj = null;
    JSONObject objData = null;
    JSONObject dataobjData = null;

    try {
        obj = new JSONObject();
        objData = new JSONObject();

        objData.put("body", msg);
        objData.put("title", title);
        objData.put("sound", "default");
        objData.put("icon", "icon_name"); //   icon_name image must be there in drawable
        objData.put("tag", token);
        objData.put("priority", "high");

        dataobjData = new JSONObject();
        dataobjData.put("text", msg);
        dataobjData.put("title", title);

        obj.put("to", token);
        //obj.put("priority", "high");

        obj.put("notification", objData);
        obj.put("data", dataobjData);
        Log.e("!_@rj@_@@_PASS:>", obj.toString());
    } catch (JSONException e) {
        e.printStackTrace();
    }

    JsonObjectRequest jsObjRequest = new JsonObjectRequest(Request.Method.POST, Constants.FCM_PUSH_URL, obj,
            new Response.Listener<JSONObject>() {
                @Override
                public void onResponse(JSONObject response) {
                    Log.e("!_@@_SUCESS", response + "");
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Log.e("!_@@_Errors--", error + "");
                }
            }) {
        @Override
        public Map<String, String> getHeaders() throws AuthFailureError {
            Map<String, String> params = new HashMap<String, String>();
            params.put("Authorization", "key=" + Legacy_SERVER_KEY);
            params.put("Content-Type", "application/json");
            return params;
        }
    };
    RequestQueue requestQueue = Volley.newRequestQueue(this);
    int socketTimeout = 1000 * 60;// 60 seconds
    RetryPolicy policy = new DefaultRetryPolicy(socketTimeout, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
    jsObjRequest.setRetryPolicy(policy);
    requestQueue.add(jsObjRequest);
}

Just Call sendFCMPush();

Answer 6

Simplest way :

void sendFCMPush(String msg,String token) {
    HttpLoggingInterceptor logging = new HttpLoggingInterceptor();
    logging.setLevel(HttpLoggingInterceptor.Level.BODY);

    OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
    httpClient.addInterceptor(new Interceptor() {
        @Override
        public okhttp3.Response intercept(Chain chain) throws IOException {
            Request original = chain.request();

            // Request customization: add request headers
            Request.Builder requestBuilder = original.newBuilder()
                    .header("Authorization", "key="+Const.FIREBASE_LEGACY_SERVER_KEY); // <-- this is the important line
            Request request = requestBuilder.build();
            return chain.proceed(request);
        }
    });

    httpClient.addInterceptor(logging);
    OkHttpClient client = httpClient.build();

    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl("https://fcm.googleapis.com/")//url of FCM message server
            .client(client)
            .addConverterFactory(GsonConverterFactory.create())//use for convert JSON file into object
            .build();

    // prepare call in Retrofit 2.0
    FirebaseAPI firebaseAPI = retrofit.create(FirebaseAPI.class);

    //for messaging server
    NotifyData notifydata = new NotifyData("Chatting", msg);

    Call<Message> call2 = firebaseAPI.sendMessage(new Message(token, notifydata));

    call2.enqueue(new Callback<Message>() {
        @Override
        public void onResponse(Call<Message> call, retrofit2.Response<Message> response) {
            Log.e("#@ SUCCES #E$#", response.body().toString());
        }

        @Override
        public void onFailure(Call<Message> call, Throwable t) {

            Log.e("E$ FAILURE E$#", t.getMessage());
        }
    });
}

Create Class to make Object:

public class Message {
String to;
NotifyData data;

public Message(String to, NotifyData data) {
    this.to = to;
    this.data = data;
}
}

Create Class to make Object:

public class Notification {
String title;
String message;
enter code here`enter code here`
public Notification(String title, String message) {
    this.title = title;
    this.message = message;
}
}