How to send notification to Android app from Java server using GCM?

Question

I have my simple Android application which uses REST web service. Now I want to sent notification from my REST web service to Android application using GCM.

How do t

Answer 1

This is a function using to send notification from java to the app android. this code use JSONObject you must add this jar into project buildpath.

note:I use fcm

 import java.io.OutputStreamWriter;
 import java.net.HttpURLConnection;
 import java.net.URL;

import org.json.JSONObject;

public class FcmNotif {
  public final static String AUTH_KEY_FCM ="AIzB***********RFA";
  public final static String API_URL_FCM = "https://fcm.googleapis.com/fcm/send";

// userDeviceIdKey is the device id you will query from your database

public void pushFCMNotification(String userDeviceIdKey, String title, String message) throws Exception{

String authKey = AUTH_KEY_FCM;   // You FCM AUTH key
String FMCurl = API_URL_FCM;     

URL url = new URL(FMCurl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();

conn.setUseCaches(false);
conn.setDoInput(true);
conn.setDoOutput(true);

conn.setRequestMethod("POST");
conn.setRequestProperty("Authorization","key="+authKey);
conn.setRequestProperty("Content-Type","application/json");

JSONObject json = new JSONObject();
json.put("to",userDeviceIdKey.trim());
JSONObject info = new JSONObject();
info.put("title", title); // Notification title
info.put("body", message); // Notification body
info.put("image", "https://lh6.googleusercontent.com/-sYITU_cFMVg/AAAAAAAAAAI/AAAAAAAAABM/JmQNdKRPSBg/photo.jpg");
info.put("type", "message");
json.put("data", info);
System.out.println(json.toString());

OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
wr.write(json.toString());
wr.flush();
conn.getInputStream();
}
}

good luck