Android - BaseAdapter

package jason.listviewsample.app;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;


public class BaseAdapterListView extends ActionBarActivity {

    ListView listView;
    String listItem;
    MyAdapter customAdapter;


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

        customAdapter = new MyAdapter();

        listView = (ListView) findViewById(R.id.listViewBaseAdapter);
        listView.setAdapter(customAdapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

            }
        });
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.base_adapter_list_view, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    public class Data {
        private String letter;
        private String number;
    }

    public ArrayList<Data> addData(){
        ArrayList<Data> listData = new ArrayList<Data>();

        Data data1 = new Data();
        data1.letter = "A";
        data1.number = "1";
        listData.add(data1);

        Data data2 = new Data();
        data2.letter = "B";
        data2.number = "2";
        listData.add(data2);

        Data data3 = new Data();
        data3.letter = "C";
        data3.number = "3";
        listData.add(data3);

        Data data4 = new Data();
        data4.letter = "D";
        data4.number = "4";
        listData.add(data4);

        return listData;
    }

    public class MyAdapter extends BaseAdapter {

        String data1[]= new String[]{"Orange", "Kiwi", "Banana", "Apple"};
        String data2[]= new String[]{"100", "200", "300", "400" };

        ArrayList<Data> listData;

        LayoutInflater inflater;

        @Override
        // looping
        public int getCount() {
            return data1.length;
        }

        @Override
        public Object getItem(int index) {
            return null;
        }

        @Override
        public long getItemId(int index) {
            return index;
        }

        @Override
        public View getView(int index, View view, ViewGroup viewGroup) {

            inflater = getLayoutInflater();
            //    LayoutInflater inflater;
            //    inflater = (LayoutInflater) BaseAdapterListView.this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            view = inflater.inflate(R.layout.list_view_design, viewGroup, false);

            TextView textView1 = (TextView)view.findViewById(R.id.textView1);
            TextView textView2 = (TextView)view.findViewById(R.id.textView2);

            textView1.setText(data1[index]);
            textView2.setText(data2[index]);

            listData = addData();
            Data data = listData.get(index);

//            textView1.setText(data.letter);
//            textView2.setText(data.number);

            return view;
        }
    }

}