How to Update RecyclerView Adapter Data in Android?

package com.gtappdevelopers.googlemapsroutes.RecyclerView;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import com.gtappdevelopers.googlemapsroutes.R;
import java.util.ArrayList;

public class Adapter extends RecyclerView.Adapter<Adapter.ViewHolder> {
    private ArrayList<String> list;

    public Adapter(ArrayList<String> list, Context context) {
        this.list = list;
    }

    @NonNull
    @Override
    public Adapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        // this method is use to inflate the layout file 
        // which we have created for our recycler view.
        // on below line we are inflating our layout file.
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_rv, parent, false);
        
        // at last we are returning our view holder
        // class with our item View File.
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull Adapter.ViewHolder holder, int position) {
        // on below line we are setting text to our text view.
        holder.textView.setText(list.get(position));
    }

    @Override
    public int getItemCount() {
        return list.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        // on below line we are creating variable. 
        private TextView textView;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            // on below line we are initialing our variable. 
            textView = itemView.findViewById(R.id.textView);
        }
    }
}

package com.gtappdevelopers.googlemapsroutes;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.RecyclerView;
import com.gtappdevelopers.googlemapsroutes.RecyclerView.LanguageRVAdapter;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    // on below line we are creating variables.
    private RecyclerView rv;
    private EditText editText;
    private Button button;
    private ArrayList<String> list;
    private Adapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        // on below line we are initializing our variables.
        rv = findViewById(R.id.rv);
        editText = findViewById(R.id.editText);
        button = findViewById(R.id.button);
        list = new ArrayList<>();

        // on below line we are adding data to our list.
        list.add("C++");
        list.add("C");
        list.add("Java");

        // on below line we are adding our list to our adapter.
        adapter = new Adapter(list);

        // on below line we are setting 
        // adapter to our recycler view.
        rv.setAdapter(adapter);

        // on below line we are adding click listener for our add button.
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // on below line we are calling 
                // add item method.
                addItem(editText.getText.toString());
            }
        });
    }

    // on below line we are creating 
    // a new function to add item.
    private void addItem(String item) {
        // on below line we are checking
        // if item is empty or not.
        if (!item.isEmpty()) {
            // on below line we are adding
            // item to our list
            list.add(item);
            // on below line we are notifying 
            // adapter that data has updated.
            adapter.notifyDataSetChanged();
        }
    }

}