Android O - Notification Channels - Change Vibration Pattern or Sound Type

You can still offer sound and vibration customization in your app, but it requires a different approach. In short, the idea is to play sound and vibration manually in Android O instead of using the notification channel (it's easier than it seems).

This is how I did it:

NotificationCompat.Builder builder = new NotificationCompat.Builder(context, channelId);

// builder.setSmallIcon(...)
// builder.setContentTitle(...)
// builder.setContentText(...)

if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {

    // play vibration
    vibrator = (Vibrator)context.getSystemService(Context.VIBRATOR_SERVICE);
    vibrator.vibrate(VibrationEffect.createWaveform(vibrationPattern, -1));

    // play sound
    Intent serviceIntent = new Intent(context, SoundService.class);
    serviceIntent.setAction("ACTION_START_PLAYBACK");
    serviceIntent.putExtra("SOUND_URI", soundUri.toString());
    context.startForegroundService(serviceIntent);

    // the delete intent will stop the sound when the notification is cleared
    Intent deleteIntent = new Intent(context, SoundService.class);
    deleteIntent.setAction("ACTION_STOP_PLAYBACK");
    PendingIntent pendingDeleteIntent =
            PendingIntent.getService(context, 0, deleteIntent, 0);
    builder.setDeleteIntent(pendingDeleteIntent);

} else {

    builder.setVibrate(vibrationPattern);
    builder.setSound(soundUri);

}

notificationManager.notify(notificationId, builder.build());

SoundService.class is the place where I play the sound with MediaPlayer:

public class SoundService extends Service {

    MediaPlayer mMediaPlayer;

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    public int onStartCommand(Intent intent, int flags, int startId) {

        // foreground notification
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationCompat.Builder builder =
                new NotificationCompat.Builder(this, otherChannelId);
            builder.setSmallIcon(...)
                    .setContentTitle(...)
                    .setContentText(...)
                    .setAutoCancel(true);
            startForeground(foregroundNotificationId, builder.build());
        }

        // check action
        String action = intent.getAction();
        switch (action) {
            case "ACTION_START_PLAYBACK":
                startSound(intent.getStringExtra("SOUND_URI"));
                break;
            case "ACTION_STOP_PLAYBACK":
                stopSound();
                break;
        }

        // service will not be recreated if abnormally terminated
        return START_NOT_STICKY;
    }

    private void startSound(String uriString) {

        // parse sound
        Uri soundUri;
        try {
            soundUri = Uri.parse(uriString);
        } catch (Exception e) {
            cleanup();
            return;
        }

        // play sound
        if (mMediaPlayer == null) {
            mMediaPlayer = new MediaPlayer();
            mMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                @Override
                public void onPrepared(MediaPlayer mp) {
                    mp.start();
                }
            });
            mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                @Override
                public void onCompletion(MediaPlayer mediaPlayer) {
                    cleanup();
                }
            });
        }
        try {
            mMediaPlayer.setDataSource(this, soundUri);
            mMediaPlayer.prepareAsync();
        } catch (Exception e) {
            cleanup();
        }

    }

    private void stopSound() {
        if (mMediaPlayer != null) {
            mMediaPlayer.stop();
            mMediaPlayer.release();
            mMediaPlayer = null;
        }
        cleanup();
    }

    private void cleanup() {
        stopSelf();
    }

}

Recommendations

• Create your notification channel with IMPORTANCE_DEFAULT (for the user this is 'High'), a null sound (setSound(null,null)) and a null vibration (setVibrationPattern(null)) and explain in the channel description that this is the recommended setting in order to avoid conflicts with the app's own customization.
• Turn the whole thing into your favor: instead of removing a feature, give users a new one. You can give them the chance to use your customization features or the notification channel features (for example, you can check the current channel importance and depending on the level you can use one thing or the other).

Foreground notification

Starting Android O, services started from the background must be started as foreground services. This means SoundService needs a foreground notification. You have some options for this:

• Create a nice foreground notification with a button that says 'Stop playback' so that the user can stop the sound without removing the notification that started it.

• Create a simple notification and send it to a disabled channel (you can create disabled channels if you create them with IMPORTANCE_NONE). Doing this, the default system 'App is running in the background' notification will appear instead of your foreground notification, but users can hide this notification from the status bar if they want.

EDIT: in Android 8.1 it seems that creating a disabled channel with IMPORTANCE_NONE is not useful, as the channel will be enabled automatically when you send a notification. It may be better to create it with IMPORTANCE_LOW from the beginning and let users change the importance if they want.

It is not a good idea to play the sound manually. The best approach would be to have two (or more) channels- one for each sound/vibration you would like to play.

In code you can decide which channel to use depending on which sound you would like to play.

Here is my code where I play either the default notification sound or a custom sound depending on the client's settings. The code also takes care of devices running Android prior to API 26:

String sound = PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).getString("NotificationsSound", getString(R.string.settingsNotificationSiren));
Uri soundUri = Uri.parse(ContentResolver.SCHEME_ANDROID_RESOURCE + "://"+ getApplicationContext().getPackageName() + "/" + R.raw.siren);
NotificationManager mNotificationManager = (NotificationManager) getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);
NotificationChannel mChannel;
String channel_id = Utils.CHANNEL_DEFAULT_ID;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
    if (sound.toLowerCase().equals(getString(R.string.settingsNotificationSiren).toLowerCase())) {
        channel_id = Utils.CHANNEL_SIREN_ID;
        mChannel = new NotificationChannel(Utils.CHANNEL_SIREN_ID, Utils.CHANNEL_SIREN_NAME, NotificationManager.IMPORTANCE_HIGH);
        mChannel.setLightColor(Color.GRAY);
        mChannel.enableLights(true);
        mChannel.setDescription(Utils.CHANNEL_SIREN_DESCRIPTION);
        AudioAttributes audioAttributes = new AudioAttributes.Builder()
                .setContentType(AudioAttributes.CONTENT_TYPE_SONIFICATION)
                .setUsage(AudioAttributes.USAGE_NOTIFICATION)
                .build();
        mChannel.setSound(soundUri, audioAttributes);
    } else {
        mChannel = new NotificationChannel(Utils.CHANNEL_DEFAULT_ID, Utils.CHANNEL_DEFAULT_NAME, NotificationManager.IMPORTANCE_HIGH);
        mChannel.setLightColor(Color.GRAY);
        mChannel.enableLights(true);
        mChannel.setDescription(Utils.CHANNEL_DEFAULT_DESCRIPTION);
    }
    if (mNotificationManager != null) {
        mNotificationManager.createNotificationChannel( mChannel );
    }
}

NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, channel_id)
        .setSmallIcon(R.drawable.ic_stat_maps_local_library)
        .setLargeIcon(BitmapFactory.decodeResource(getApplicationContext().getResources(), R.mipmap.ic_launcher))
        .setTicker(title)
        .setContentTitle(contentTitle)
        .setContentText(contentText)
        .setAutoCancel(true)
        .setLights(0xff0000ff, 300, 1000) // blue color
        .setWhen(System.currentTimeMillis())
        .setPriority(NotificationCompat.PRIORITY_DEFAULT);

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
    if (sound.toLowerCase().equals(getString(R.string.settingsNotificationSiren).toLowerCase())) {
        mBuilder.setSound(soundUri);
    } else {
        mBuilder.setSound(RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION));
    }
}

int NOTIFICATION_ID = 1; // Causes to update the same notification over and over again.
if (mNotificationManager != null) {
    mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
}