Creating a NotificationChannel throws an IllegalArgumentException

Question

The app works on previous versions of Android, but not on Oreo. It's a WebView with Notifications. I've been researching this error and haven't found anything similar.

The stack trace:

E/AndroidRuntime: FATAL EXCEPTION: main
Process: net.oneteamit.tk, PID: 3171
java.lang.RuntimeException: Unable to start activity ComponentInfo{net.oneteamit.tk/net.oneteamit.tk.MainActivity}:
    java.lang.IllegalArgumentException
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2817)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892)
    at android.app.ActivityThread.-wrap11(Unknown Source:0)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593)
    at android.os.Handler.dispatchMessage(Handler.java:105)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6541)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
 Caused by: java.lang.IllegalArgumentException
    at android.os.Parcel.readException(Parcel.java:1946)
    at android.os.Parcel.readException(Parcel.java:1888)
    at android.app.INotificationManager$Stub$Proxy.createNotificationChannels(INotificationManager.java:1418)
    at android.app.NotificationManager.createNotificationChannels(NotificationManager.java:446)
    at android.app.NotificationManager.createNotificationChannel(NotificationManager.java:434)
    at net.oneteamit.tk.MainActivity.onCreate(MainActivity.java:47)
    at android.app.Activity.performCreate(Activity.java:6975)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1213)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2770)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2892) 
    at android.app.ActivityThread.-wrap11(Unknown Source:0) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1593) 
    at android.os.Handler.dispatchMessage(Handler.java:105) 
    at android.os.Looper.loop(Looper.java:164) 
    at android.app.ActivityThread.main(ActivityThread.java:6541) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767) 

MainActivity:

public class MainActivity extends AppCompatActivity {

    private WebView mWebView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mWebView = (WebView) findViewById(R.id.activity_main_webview);
        WebSettings webSettings = mWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        mWebView.loadUrl("My test URL");
        mWebView.setWebViewClient(new WebViewClient());
        mWebView.getSettings().setAppCacheEnabled(false);
        mWebView.clearCache(true);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            // Create channel to show notifications.
            String channelId  = getString(R.string.default_notification_channel_id);
            String channelName = getString(R.string.default_notification_channel_name);

            NotificationManager notificationManager =
                getSystemService(NotificationManager.class);

            notificationManager.createNotificationChannel(
                new NotificationChannel(channelId,
                                        channelName,
                                        NotificationManager.IMPORTANCE_LOW));
        }

        mWebView.getSettings().setUseWideViewPort(true);
        mWebView.getSettings().setLoadWithOverviewMode(true);
        mWebView.setInitialScale(1);
        mWebView.getSettings().setBuiltInZoomControls(true);
    }
}

Answer 1

This exception occurs when the channel name is invalid. I was able to reproduce the stack trace by running with an empty channel name:

<string name="default_notification_channel_name"></string>

Check the value you have defined for default_notification_channel_name and change it to a valid value.