Android Notification show 

public static void shownotification(Context context, int id, String title, String Content, Intent intent)
{
    PendingIntent pendingIntent=null;
    if (intent!=null)
    {
        pendingIntent=PendingIntent.getActivities(context,id, new Intent[]{intent},PendingIntent.FLAG_UPDATE_CURRENT);
        String NOTIIFCATION_CHANNEL_ID="UClone android";
        NotificationManager notificationManager= (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        if (Build.VERSION.SDK_INT>=Build.VERSION_CODES.O)
        {
            NotificationChannel notificationChannel=new NotificationChannel(NOTIIFCATION_CHANNEL_ID,"",NotificationManager.IMPORTANCE_HIGH);
            notificationChannel.setDescription("");
            notificationChannel.enableLights(true);
            notificationChannel.setLightColor(Color.RED);
            notificationChannel.setVibrationPattern(new long[]{0,1000,500,1000});
            notificationChannel.enableVibration(true);

            notificationManager.createNotificationChannel(notificationChannel);

        }
        NotificationCompat.Builder builder=new NotificationCompat.Builder(context,NOTIIFCATION_CHANNEL_ID);
        builder.setContentTitle(title);
        builder.setContentText(Content);
        builder.setAutoCancel(false);
        builder.setPriority(NotificationCompat.PRIORITY_HIGH);
        builder.setDefaults(Notification.DEFAULT_VIBRATE);
        builder.setSmallIcon(R.drawable.car);
        builder.setLargeIcon(BitmapFactory.decodeResource(context.getResources(),R.drawable.car_display));

        if (pendingIntent!=null)
        {
            builder.setContentIntent(pendingIntent);
        }
        Notification notification= builder.build();
        notificationManager.notify(id,notification);

    }


}

Example: 2

private void addNotification() {
    NotificationCompat.Builder builder =
            new NotificationCompat.Builder(this)
                    .setSmallIcon(R.drawable.messageicon) //set icon for notification  
                    .setContentTitle("Notifications Example") //set title of notification  
                    .setContentText("This is a notification message")//this is notification message  
                    .setAutoCancel(true) // makes auto cancel of notification  
                    .setPriority(NotificationCompat.PRIORITY_DEFAULT); //set priority of notification  


    Intent notificationIntent = new Intent(this, NotificationView.class);
    notificationIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    //notification message will get at NotificationView  
    notificationIntent.putExtra("message", "This is a notification message");

    PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, notificationIntent,
            PendingIntent.FLAG_UPDATE_CURRENT);
    builder.setContentIntent(pendingIntent);

    // Add as notification  
    NotificationManager manager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    manager.notify(0, builder.build());
}