How to Create a Reminder Notification in Android?

This example demonstrate about How to Create a Reminder Notification in Android
Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.
Step 2 − Add the following code to res/layout/activity_main.xml.
<? xml version = "1.0" encoding= "utf-8" ?>
<RelativeLayout xmlns:android = "http://schemas.android.com/apk/res/android"
   xmlns:tools = "http://schemas.android.com/tools"
   android:layout_width = "match_parent"
   android:layout_height = "match_parent"
   android:padding = "16dp"
   tools:context = ".MainActivity">
   <Button
      android:onClick= "createNotification"
      android:text= "create notification"
      android:layout_centerInParent= "true"
      android:layout_width= "match_parent"
      android:layout_height= "wrap_content" />
</RelativeLayout>
Step 3 − Add the following code to src/MainActivity.
package app.tutorialspoint.com.notifyme ;
import android.app.AlarmManager ;
import android.app.PendingIntent ;
import android.content.Intent ;
import android.os.Bundle ;
import android.support.v7.app.AppCompatActivity ;
import android.view.View ;
import java.util.Calendar ;
public class MainActivity extends AppCompatActivity {
   @Override
   protected void onCreate (Bundle savedInstanceState) {
      super .onCreate(savedInstanceState) ;
      setContentView(R.layout. activity_main ) ;
   }
   public void createNotification (View view) {
      Intent myIntent = new Intent(getApplicationContext() , NotifyService. class ) ;
      AlarmManager alarmManager = (AlarmManager) getSystemService( ALARM_SERVICE ) ;
      PendingIntent pendingIntent = PendingIntent. getService ( this, 0 , myIntent , 0 ) ;
      Calendar calendar = Calendar. getInstance () ;
      calendar.set(Calendar. SECOND , 0 ) ;
      calendar.set(Calendar. MINUTE , 0 ) ;
      calendar.set(Calendar. HOUR , 0 ) ;
      calendar.set(Calendar. AM_PM , Calendar. AM ) ;
      calendar.add(Calendar. DAY_OF_MONTH , 1 ) ;
      alarmManager.setRepeating(AlarmManager. RTC_WAKEUP , calendar.getTimeInMillis() , 1000 * 60 * 60 * 24 , pendingIntent) ;
   }
}
Step 4 − Add the following code to src/NotifyService
package app.tutorialspoint.com.notifyme ;
import android.app.NotificationChannel ;
import android.app.NotificationManager ;
import android.app.PendingIntent ;
import android.app.Service ;
import android.content.Intent ;
import android.os.IBinder ;
import android.support.v4.app.NotificationCompat ;
public class NotifyService extends Service {
   public static final String NOTIFICATION_CHANNEL_ID = "10001" ;
   private final static String default_notification_channel_id = "default" ;
   public NotifyService () {
   }
   @Override
   public IBinder onBind (Intent intent) {
      Intent notificationIntent = new Intent(getApplicationContext() ,  MainActivity. class ) ;
      notificationIntent.putExtra( "fromNotification" , true ) ;
      notificationIntent.setFlags(Intent. FLAG_ACTIVITY_CLEAR_TOP | Intent. FLAG_ACTIVITY_SINGLE_TOP ) ;
      PendingIntent pendingIntent = PendingIntent. getActivity ( this, 0 , notificationIntent , 0 ) ;
      NotificationManager mNotificationManager = (NotificationManager) getSystemService( NOTIFICATION_SERVICE ) ;
      NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getApplicationContext() , default_notification_channel_id ) ;
      mBuilder.setContentTitle( "My Notification" ) ;
      mBuilder.setContentIntent(pendingIntent) ;
      mBuilder.setContentText( "Notification Listener Service Example" ) ;
      mBuilder.setSmallIcon(R.drawable. ic_launcher_foreground ) ;
      mBuilder.setAutoCancel( true ) ;
      if (android.os.Build.VERSION. SDK_INT >= android.os.Build.VERSION_CODES. O ) {
         int importance = NotificationManager. IMPORTANCE_HIGH ;
         NotificationChannel notificationChannel = new
         NotificationChannel( NOTIFICATION_CHANNEL_ID , "NOTIFICATION_CHANNEL_NAME" , importance) ;
         mBuilder.setChannelId( NOTIFICATION_CHANNEL_ID ) ;
         assert mNotificationManager != null;
         mNotificationManager.createNotificationChannel(notificationChannel) ;
      }
      assert mNotificationManager != null;
      mNotificationManager.notify(( int ) System. currentTimeMillis () , mBuilder.build()) ;
      throw new UnsupportedOperationException( "Not yet implemented" ) ;
   }
}
Step 5 − Add the following code to AndroidManifest.xml
<? xml version= "1.0" encoding= "utf-8" ?>
<manifest xmlns: android = "http://schemas.android.com/apk/res/android"
   package = "app.tutorialspoint.com.notifyme" >
   <uses-permission android :name = "android.permission.VIBRATE" />
   <uses-permission android :name = "android.permission.RECEIVE_BOOT_COMPLETED" />
   <application
      android :allowBackup = "true"
      android :icon = "@mipmap/ic_launcher"
      android :label = "@string/app_name"
      android :roundIcon = "@mipmap/ic_launcher_round"
      android :supportsRtl = "true"
      android :theme = "@style/AppTheme" >
      <service
         android :name = ".NotifyService"
         android :enabled = "true"
         android :exported = "true" >
      </service>
      <activity android :name = ".MainActivity" >
         <intent-filter>
            <action android :name = "android.intent.action.MAIN" />
            <category android :name = "android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>
Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run  icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen.
Click  here  to download the project code