Android - Problema 1 programa

package hitesh.sqlapp;

import android.app.Activity;

import android.content.Intent;

import android.os.AsyncTask;

import android.os.Bundle;

import android.view.View;

import android.widget.AdapterView;

import android.widget.ListView;

import android.widget.ProgressBar;

import android.widget.SimpleAdapter;

import android.widget.Toast;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

/**

 * Created by Carlos on 11-02-2016.

 */

public class Clientes extends Activity {

    ConnectionClass connectionClass;

    ProgressBar pbbarc;

    ListView lstcli;

    String cliid;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.clientes);

        connectionClass = new ConnectionClass();

        pbbarc = (ProgressBar) findViewById(R.id.pbbarc);

        pbbarc.setVisibility(View.GONE);

        lstcli = (ListView) findViewById(R.id.listcli);

        cliid = getIntent().getStringExtra("proid");

    }

    FillListc fillList = new FillListc();

    fillList.execute("");

    public class FillListc extends AsyncTask<String,String,String> {

        String a = "";

        List<Map<String, String>> prolistc = new ArrayList<Map<String, String>>();

        @Override

        protected void onPreExecute() {

            pbbarc.setVisibility(View.VISIBLE);

        }

        protected void onPostExecute(String r) {

            pbbarc.setVisibility(View.GONE);

            Toast.makeText(Clientes.this, r, Toast.LENGTH_SHORT).show();

            String[] from={"A","B","C"};

           // int[] views = {R.id.lblproid, R.id.lblproname,R.id.lblprodesc};

            final SimpleAdapter ADA = new SimpleAdapter(Clientes.this,

                    prolistc, R.layout.clientes, from,

                    views);

            lstcli.setAdapter(ADA);

            lstcli.setOnItemClickListener(new AdapterView.OnItemClickListener() {

                @Override

                public void onItemClick(AdapterView<?> arg0, View arg1,

                                        int arg2, long arg3) {

                    HashMap<String, Object> obj = (HashMap<String, Object>) ADA

                            .getItem(arg2);

                    cliid = (String) obj.get("A");

                    String proname = (String) obj.get("B");

                    // String prodesc = (String) obj.get("C");

                    // edtprodesc.setText(prodesc);

                    //  edtproname.setText(proname);

                    // qty.setText(qtys);

                }

            });

        }

        @Override

        protected String doInBackground(String... params) {

            try {

                Connection con = connectionClass.CONN();

                if (con == null) {

                    a = "Error in connection with SQL server";

                } else {

                    String query = "SELECT Codigo, Descripcion FROM dbo.SectoresPalm Order by Descripcion";

                    PreparedStatement ps = con.prepareStatement(query);

                    ResultSet rs = ps.executeQuery();

                    ArrayList<String> data1 = new ArrayList<String>();

                    while (rs.next()) {

                        Map<String, String> datanum = new HashMap<String, String>();

                        datanum.put("A", rs.getString("Codigo"));

                        datanum.put("B", rs.getString("Descripcion"));

                        // datanum.put("C", rs.getString("ProDesc"));

                       lstcli.add(datanum);

                    }

                    a = "Success";

                }

            } catch (Exception ex) {

               a  = "Error retrieving data from table";

            }

            return a;

        }

    }

}