android spinner example java

different files

MainActivity.java:

package com.sunmeat.myapplication;

import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    Spinner spinner;
    ArrayAdapter<String> adapter;

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

        spinner = findViewById(R.id.spin1);
        String[] info = {"Armin van Buuren", "Madonna", "Hurts", "Metallica", "Bjork", "Океан Ельзи"};
        adapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, info);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(adapter);

        spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int pos, long l) {
                Toast.makeText(parent.getContext(),
                        "OnItemSelectedListener : " + parent.getItemAtPosition(pos).toString(),
                        Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {

            }
        });
    }
}

==================================================================================

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Spinner
        android:id="@+id/spin1"
        android:layout_gravity="top"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>