How to send one to one message using Firebase Messaging

Question

I have been trying to read the official docs and guides about how to send message from one device to another. I have saved registration token of both devices in the Real Tim

Answer 1

I am late but above solutions has helped me to write down this simple answer, you can send your message directly to android devices from android application, here is the simple implementation I have done and it works great for me.

1. compile android volley library

   compile 'com.android.volley:volley:1.0.0'
   

2. Just copy paste this simple function ;) and your life will become smooth just like knife in butter. :D

   public static void sendPushToSingleInstance(final Context activity, final HashMap dataValue /*your data from the activity*/, final String instanceIdToken /*firebase instance token you will find in documentation that how to get this*/ ) {
   
   
   final String url = "https://fcm.googleapis.com/fcm/send";
   StringRequest myReq = new StringRequest(Request.Method.POST,url,
           new Response.Listener() {
               @Override
               public void onResponse(String response) {
                   Toast.makeText(activity, "Bingo Success", Toast.LENGTH_SHORT).show();
               }
           },
           new Response.ErrorListener() {
               @Override
               public void onErrorResponse(VolleyError error) {
                   Toast.makeText(activity, "Oops error", Toast.LENGTH_SHORT).show();
               }
           }) {
   
       @Override
       public byte[] getBody() throws com.android.volley.AuthFailureError {
           Map rawParameters = new Hashtable();
           rawParameters.put("data", new JSONObject(dataValue));
           rawParameters.put("to", instanceIdToken);
           return new JSONObject(rawParameters).toString().getBytes();
       };
   
       public String getBodyContentType()
       {
           return "application/json; charset=utf-8";
       }
       @Override
       public Map getHeaders() throws AuthFailureError {
           HashMap headers = new HashMap();
           headers.put("Authorization", "key="+YOUR_LEGACY_SERVER_KEY_FROM_FIREBASE_CONSOLE);
           headers.put("Content-Type","application/json");
           return headers;
       }
   
   };
   
   Volley.newRequestQueue(activity).add(myReq);
   }
   

Note If you want to send message to topics so you can change parameter instanceIdToken to something like /topics/topicName. For groups implementation is the same but you just need to take care of parameters. checkout Firebase documentation and you can pass those parameters. let me know if you face any issue.