What Are Notification Channels?

Notification channels enable us app developers to group our notifications into groups—channels—with the user having the ability to modify notification settings for the entire channel at once. For example, for each channel, users can completely block all notifications, override the importance level, or allow a notification badge to be shown. This new feature helps in greatly improving the user experience of an app.

Create Notification Channels

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.Context;
import android.content.ContextWrapper;
import android.graphics.Color;

public class NotificationUtils extends ContextWrapper {

private NotificationManager mManager;
public static final String ANDROID_CHANNEL_ID = "com.sai.ANDROID";
public static final String IOS_CHANNEL_ID = "com.sai.IOS";
public static final String ANDROID_CHANNEL_NAME = "ANDROID CHANNEL";
public static final String IOS_CHANNEL_NAME = "IOS CHANNEL";

public NotificationUtils(Context base) {
    super(base);
    createChannels();
}

public void createChannels() {

// create android channel
NotificationChannel androidChannel = new NotificationChannel(ANDROID_CHANNEL_ID,
        ANDROID_CHANNEL_NAME, NotificationManager.IMPORTANCE_DEFAULT);
// Sets whether notifications posted to this channel should display notification lights
androidChannel.enableLights(true);
// Sets whether notification posted to this channel should vibrate.
androidChannel.enableVibration(true);
// Sets the notification light color for notifications posted to this channel
androidChannel.setLightColor(Color.BLUE);
// Sets whether notifications posted to this channel appear on the lockscreen or not
androidChannel.setLockscreenVisibility(Notification.VISIBILITY_PRIVATE);

getManager().createNotificationChannel(androidChannel);

// create ios channel
NotificationChannel iosChannel = new NotificationChannel(IOS_CHANNEL_ID,
        IOS_CHANNEL_NAME, NotificationManager.IMPORTANCE_HIGH);
iosChannel.enableLights(true);
iosChannel.enableVibration(true);
iosChannel.setLightColor(Color.GRAY);
iosChannel.setLockscreenVisibility(Notification.VISIBILITY_PUBLIC);
getManager().createNotificationChannel(iosChannel);

}

private NotificationManager getManager() {
    if (mManager == null) {
        mManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    }
    return mManager;
}}

In the code above, we created two instances of the NotificationChannel, passing uniqueid a channel name, and also an importance level in its constructor. For each notification channel, we applied following characteristics.

1. Sound
2. Lights
3. Vibration
4. Notification to show on lock screen.

Finally, we got the NotificationManager from the system and then registered the channel by calling the method createNotificationChannel(), passing the channel we have created.

We can create multiple notification channels all at once with createNotificationChannels(), passing a Java list of NotificationChannel instances. You can get all notification channels for an app with getNotificationChannels() and get a specific channel with getNotificationChannel(), passing only the channel id as an argument.

Importance Level in Notification Channels