Notification not working in android version Oreo

Question

I am trying to generate an 'onclick' notification just for learning purposes in android studio, sdk version Oreo. But I just cant get it to work. I have also created a notification channel but it isn't working. Can someone please tell what is the issue in the java code.

package com.example.notificationexample;

import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.media.RingtoneManager;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.NotificationCompat;


public class MainActivity extends AppCompatActivity {


    Button button;
    private  final String CHANNEL_ID = "perosnal_notifications";
    private final int NOTIFICATION_ID = 001;

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

        button = findViewById(R.id.click);
        final long [] vibe = {0,500};
        final Uri notificationsound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                createNotificationChannel();
                NotificationCompat.Builder mbuilder = (NotificationCompat.Builder)
                        new NotificationCompat.Builder(getApplicationContext())
                                .setSmallIcon(R.drawable.yo,10)
                                .setSound(notificationsound)
                                .setVibrate(vibe)
                                .setContentTitle("Notification")
                                .setContentText("This is a notification for you");

                NotificationManager notificationManager = (NotificationManager)
                        getSystemService(NOTIFICATION_SERVICE);
                notificationManager.notify(NOTIFICATION_ID,mbuilder.build());
            }
        });

    }

    private void createNotificationChannel()
    {
        if(Build.VERSION.SDK_INT>=Build.VERSION_CODES.O)
        {
            CharSequence name = "Personal not";
            String description = "Include all personal nots";
            int importance = NotificationManager.IMPORTANCE_DEFAULT;

            NotificationChannel notificationChannel = new NotificationChannel(CHANNEL_ID, name, importance);

            notificationChannel.setDescription(description);

            NotificationManager notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
            notificationManager.createNotificationChannel(notificationChannel);
        }
    }
}

XML code

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/click"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:textSize="30sp"
        android:text="Notofication"/>

</RelativeLayout>

The application displays an error saying: "developer warning for package.. Failed to post notification on channel 'personal_notifications'"

Android version of virtual device is 11

Answer 1

Add channel id to builder:

NotificationCompat.Builder mbuilder = (NotificationCompat.Builder)
                        new NotificationCompat.Builder(getApplicationContext(), 
CHANNEL_ID)// add channel id