Spinner(Write a program to spin four items) |Android Program|

Activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <TextView
        android:id="@+id/selection"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="TextView"
        android:background="#FFC107"
        android:textColor="#ff0000"
        android:textSize="25dp"
        android:textStyle="bold"/>

    <Spinner
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/spinner"/>
</LinearLayout>

MainActivity.java

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

public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
    TextView selection;
    String[] items={"COMPUTER","MOUSE","KEYBOARD","PRINTER"};



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

        selection=findViewById(R.id.selection);
        Spinner spinner=findViewById(R.id.spinner);
        spinner.setOnItemSelectedListener(this);
        ArrayAdapter aa=new ArrayAdapter(this,android.R.layout.simple_spinner_item,items);

        aa.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(aa);
    }

    @Override
    public void onItemSelected(AdapterView<?> parent, View v, int position, long id) {
        selection.setText(items[position]);
    }

    @Override
    public void onNothingSelected(AdapterView<?> parent) {
        selection.setText("");
    }
}


Design