Android and HashSet (Java)

package com.myapp;

import java.util.HashSet;
import java.util.Iterator;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends Activity {

	ArrayAdapter<String> adapter;
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
 
        /**** Sample 1 ****/ 
        HashSet<String> myHashSet = new HashSet<String>();
        myHashSet.add("Belgium");
        myHashSet.add("France");
        myHashSet.add("Italy");
        myHashSet.add("Germany");
        
        // Get Size HashSet
        final TextView txtView1 = (TextView)findViewById(R.id.textView1); 
        txtView1.setText("HashSet Size = " + myHashSet.size());
        
        // Loop Data HashSet
        final TextView txtView2 = (TextView)findViewById(R.id.textView2); 
        txtView2.setText("");
        Iterator itr = myHashSet.iterator();
        while(itr.hasNext())
        {
          txtView2.setText(txtView2.getText() +  itr.next().toString() + ",");
      	}
    
        
        // Convert HashSet to Array
		String[] myArr = {};
		myArr = myHashSet.toArray(new String[myHashSet.size()]);
		
		// Show Array to ListView
        final ListView lView = (ListView)findViewById(R.id.listView1); 
        adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, myArr);
        lView.setAdapter(adapter);
        
    }
    
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
	
}