Android 9 Development Cookbook - Third Edition

Monitoring network state changes

If your application needs to respond to changes in the network status, take a look at CONNECTIVITY_ACTION in ConnectivityManager.  There are two ways to set up the filters to be notified of connectivity change events:

• Through the Android Manifest
• Through code

Here's an example of how to include the action in the receiver's intent filter through the Android Manifest:

<receiver android:name=".MyBroadcastReceiver"> 
    <intent-filter> 
        <action android:name="android.net.conn.CONNECTIVITY_CHANGE" /> 
    </intent-filter> 
</receiver> 

Be careful using the Android Manifest as it will notify your app every time the network state changes, even if your app isn't being used. This can cause unnecessary drain on the battery.  ...