【Android】Firebaseでプッシュ通知を受け取るアプリの実装例

plugins {
  id 'com.android.application' version '7.2.2' apply false
  // ...

  // the Google services Gradle plugin for Firebase
  id("com.google.gms.google-services") version "4.3.15" apply false
}

plugins {
  id("com.android.application")

  // the Google services Gradle plugin for Firebase
  id("com.google.gms.google-services")
}

dependencies {
  // ...

  // Firebase (FCM)
  // Firebase Android BoM (https://firebase.google.com/docs/android/learn-more?hl=ja#bom)
  implementation(platform("com.google.firebase:firebase-bom:32.3.1"))
  implementation "com.google.firebase:firebase-messaging-ktx"
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.yamaday0u.push_notification_practice">

    <application>

        <activity>
            <!-- ... -->
        </activity>

        <service
            android:name=".service.MyFirebaseMessagingService"
            android:exported="false">
            <intent-filter>
                <action android:name="com.google.firebase.MESSAGING_EVENT" />
            </intent-filter>
        </service>
    </application>

</manifest>

package com.yamaday0u.push_notification_practice.service

import android.util.Log
import com.google.firebase.messaging.FirebaseMessagingService
import com.google.firebase.messaging.RemoteMessage


class MyFirebaseMessagingService: FirebaseMessagingService() {
    private val tag: String = "DEBUG"

    override fun onMessageReceived(remoteMessage: RemoteMessage) {
        Log.d(tag, "From: ${remoteMessage.from}")

        remoteMessage.notification?.let {
            Log.d(tag, "Notification - title: ${it.title}")
            Log.d(tag, "Notification - body : ${it.body}")
        } ?: Log.d(tag, "No Notification")
        
        if (remoteMessage.data.isNotEmpty()) {
            Log.d(tag, "Data: ${remoteMessage.data}")
        } else {
            Log.d(tag, "No Data")
        }
        
    }

    override fun onNewToken(token: String) {
        Log.d(tag, "Refreshed token: $token")
    }
}

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        getFirebaseToken()
        // ...
    }
}

// ...

private fun getFirebaseToken() {
    FirebaseMessaging.getInstance().token.addOnCompleteListener(OnCompleteListener { task ->
        if (!task.isSuccessful) {
            return@OnCompleteListener
        }
        val token = task.result
        Log.d("DEBUG", "token: $token")
    })
}

{
   "message":{
      "token":"取得したFirebaseのトークン",
      "notification":{
        "title":"FCM Message",
        "body":"This is an FCM notification message by yamaday0u!"
      },
      "data": {
        "story_id": "story_12345"
    }
   }
}