Android Push Notification Example Java

1/  your app needs to send or show notifications, you must add the proper permission in the AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Notification">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service
        android:name=".MyFirebaseService"
        android:exported="true">
        <intent-filter>
            <action android:name="com.google.firebase.MESSAGING_EVENT" />
        </intent-filter>
    </service>


    </application>

</manifest>

2/  This service handles incoming Firebase Cloud Messages and shows notifications to the user

package com.example.notification;

import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.pm.PackageManager;
import android.os.Build;

import androidx.annotation.NonNull;
import androidx.core.app.ActivityCompat;
import androidx.core.app.NotificationCompat;
import androidx.core.app.NotificationManagerCompat;

import com.google.firebase.messaging.FirebaseMessagingService;
import com.google.firebase.messaging.RemoteMessage;

public class MyFirebaseService extends FirebaseMessagingService {

    @Override
    public void onMessageReceived(@NonNull RemoteMessage message) {
        super.onMessageReceived(message);

        // Step 1: Create notification channel for Android O and above
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(
                    "fcm_notification",                // Channel ID
                    "FCM Notification",                // Channel Name
                    NotificationManager.IMPORTANCE_HIGH // Channel importance
            );
            NotificationManager manager = getSystemService(NotificationManager.class);
            if (manager != null) {
                manager.createNotificationChannel(channel);
            }
        }

        // Step 2: Build notification if message contains notification payload
        if (message.getNotification() != null) {
            NotificationCompat.Builder builder = new NotificationCompat.Builder(this, "fcm_notification")
                    .setSmallIcon(R.drawable.outline_ac_unit_24) // Notification icon
                    .setContentTitle(message.getNotification().getTitle()) // Notification title
                    .setContentText(message.getNotification().getBody())   // Notification body
                    .setAutoCancel(true) // Auto-dismiss when tapped
                    .setPriority(NotificationCompat.PRIORITY_HIGH); // High priority

            NotificationManagerCompat managerCompat = NotificationManagerCompat.from(this);

            // Step 3: Check POST_NOTIFICATIONS permission (required for Android 13+)
            if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.POST_NOTIFICATIONS)
                    != PackageManager.PERMISSION_GRANTED) {
                return; // Exit if permission is not granted
            }

            // Step 4: Show the notification
            managerCompat.notify(111, builder.build());
        }
    }
}

3/ This activity requests the notification permission on Android 13+ devices.  

package com.example.notification;

import android.Manifest;
import android.os.Build;
import android.os.Bundle;

import androidx.activity.result.ActivityResultLauncher;
import androidx.activity.result.contract.ActivityResultContracts;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.ContextCompat;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Step 1: Check if Android version is 13+ (Tiramisu)
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {

            // Step 2: Check if POST_NOTIFICATIONS permission is already granted
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.POST_NOTIFICATIONS)
                    != android.content.pm.PackageManager.PERMISSION_GRANTED) {

                // Step 3: Create a launcher to request permission
                ActivityResultLauncher<String> requestPermissionLauncher =
                        registerForActivityResult(
                                new ActivityResultContracts.RequestPermission(),
                                isGranted -> {

                                    // Step 4: Optional: handle user's response here
                                    if (isGranted) {
                                        // Permission granted
                                    } else {
                                        // Permission denied
                                    }
                                });

                // Step 5: Launch the permission request
                requestPermissionLauncher.launch(Manifest.permission.POST_NOTIFICATIONS);
            }
        }
    }
}

4/ This dependency adds Firebase Cloud Messaging (FCM) support for handling push notifications in the app.

dependencies {

    implementation(libs.appcompat)
    implementation(libs.material)
    implementation(libs.activity)
    implementation(libs.constraintlayout)
    testImplementation(libs.junit)
    androidTestImplementation(libs.ext.junit)
    androidTestImplementation(libs.espresso.core)
    implementation("com.google.firebase:firebase-messaging:24.0.0")

}