<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/idRLView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <!--text view for receiving our data updates
        using broad cast manager-->
    <TextView
        android:id="@+id/idTVHeading"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:padding="10dp"
        android:text="Welcome"
        android:textAlignment="center"
        android:textAllCaps="false"
        android:textColor="@color/black"
        android:textSize="30sp" />

    <!--button for sending the updated data with 
        the help of broad cast manager-->
    <Button
        android:id="@+id/idBtnStartBroadCast"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/idTVHeading"
        android:layout_centerInParent="true"
        android:layout_marginTop="30dp"
        android:text="Send BroadCast"
        android:textAllCaps="false" />

</RelativeLayout>

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;
import androidx.localbroadcastmanager.content.LocalBroadcastManager;

public class MainActivity extends AppCompatActivity {

    // creating a variable for 
    // our text view and button
    private TextView headingTV;
    private Button sendBroadCastBtn;

    // on below line we are creating a new broad cast manager.
    private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
        // we will receive data updates in onRecieve method.
        @Override
        public void onReceive(Context context, Intent intent) {
            // Get extra data included in the Intent
            String message = intent.getStringExtra("message");
            // on below line we are updating the data in our text view.
            headingTV.setText(message);
        }
    };

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

        // initializing our variables.
        headingTV = findViewById(R.id.idTVHeading);
        sendBroadCastBtn = findViewById(R.id.idBtnStartBroadCast);

        // on below line we are registering our local broadcast manager.
        LocalBroadcastManager.getInstance(this).registerReceiver(broadcastReceiver, new IntentFilter("custom-action-local-broadcast"));

        // on below line we are adding click listener to our button
        sendBroadCastBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // inside on click we are calling the intent with the action.
                Intent intent = new Intent("custom-action-local-broadcast");
                // on below line we are passing data to our broad cast receiver with key and value pair.
                intent.putExtra("message", "Welcome \n to \n Geeks For Geeks");
                // on below line we are sending our broad cast with intent using broad cast manager.
                LocalBroadcastManager.getInstance(MainActivity.this).sendBroadcast(intent);
            }
        });
    }
}