SearchView from ArrayList

1/  Design The xml

<?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:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">


    <SearchView
        android:background="@color/white"
        android:id="@+id/searchViewId"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:queryHint="Search"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"
        android:layout_below="@+id/searchViewId"
        app:layout_constraintTop_toBottomOf="@+id/searchViewId"/>


</RelativeLayout>

2/  MainActivity- Used a listView to show data. 

package com.tutorialb.searchviewfromarraylist;

import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.SearchView;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    ListView listView;
    SearchView search_bar;
    ArrayAdapter<String> adapter;
    ArrayList<String> countryList = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
            return insets;
        });
        listView = findViewById(R.id.listView);
        search_bar = findViewById(R.id.searchViewId);

        countryList.add("Argentina");
        countryList.add("Qatar");
        countryList.add("Kuwait");
        countryList.add("Bangladesh");
        countryList.add("Saudi arabia");
        countryList.add("Baharain");
        countryList.add("Pakistan");
        countryList.add("Nepal");

        adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, countryList);
        listView.setAdapter(adapter);

        search_bar.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                adapter.getFilter().filter(query);
                return false;
            }
            @Override
            public boolean onQueryTextChange(String newText) {
                adapter.getFilter().filter(newText);
                return false;
            }
        });



    }
}

3/ Run and See the output