Send Google FCM Push Notification Using Spring Boot

import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.net.HttpURLConnection; import java.net.URL; import org.json.JSONObject; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import com.esense.touch.dbconstants.NOTIFICATION; import com.esense.touch.dbconstants.STORY; import com.esense.touch.dbconstants.USER_NOTIFICATION; import com.esense.touch.dbconstants.USER_ROLE; import com.esense.touch.dbconstants.USER_ROLE_DETAIL; import com.esense.touch.service.NotificationService; @Service public class PushNotificationService { private String AUTH_KEY_FCM="your server auth key"; @Autowired NotificationService notificationService; public String sendPushNotification(Rows row) throws IOException { String result = ""; URL url = new URL(Constants.API_URL_FCM); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setUseCaches(false); conn.setDoInput(true); conn.setDoOutput(true); conn.setRequestMethod("POST"); conn.setRequestProperty("Authorization", "key=" + AUTH_KEY_FCM); conn.setRequestProperty("Content-Type", "application/json"); try { JSONObject json = new JSONObject(); json.put("to", "device Id"); JSONObject info = new JSONObject(); String notificationTitle = "Notification"; info.put("title", notificationTitle); info.put("body", "Content"); info.put("image","abc/abc.jpg"); json.put("data", info); OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream()); wr.write(json.toString()); wr.flush(); BufferedReader br = new BufferedReader(new InputStreamReader((conn.getInputStream()))); StringBuilder sb = new StringBuilder(); String output; while ((output = br.readLine()) != null) { sb.append(output); } JSONObject outputobj = new JSONObject(sb.toString()); if(outputobj.get("success").equals(1)){ // success you can write your success code here } result = "success"; } catch (Exception e) { e.printStackTrace(); result = "failure"; } return result; } }