i am working on a javafx project and i need your help . while i am trying to get selected data from table i can get selected data from normal cell but can't get data from ObservableList inside tableview.

code for my database:

-- phpMyAdmin SQL Dump
-- version 4.0.4
-- http://www.phpmyadmin.net
--
-- Host: localhost
-- Generation Time: Jun 10, 2014 at 06:20 AM
-- Server version: 5.1.33-community
-- PHP Version: 5.4.12

SET SQL_MODE = "NO_AUTO_VALUE_ON_ZERO";
SET time_zone = "+00:00";


/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;

--
-- Database: `test`
--

-- --------------------------------------------------------

--
-- Table structure for table `customer`
--

CREATE TABLE IF NOT EXISTS `customer` (
  `col0` int(11) NOT NULL,
  `col1` varchar(255) DEFAULT NULL,
  `col2` int(11) DEFAULT NULL,
  PRIMARY KEY (`col0`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

--
-- Dumping data for table `customer`
--

INSERT INTO `customer` (`col0`, `col1`, `col2`) VALUES
(12, 'adasdasd', 231),
(22, 'adasdasd', 231),
(212, 'adasdasd', 231);

/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;

my javafx codes:

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Map;
import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableColumn.CellDataFeatures;
import javafx.scene.control.TablePosition;
import javafx.scene.control.TableView;
import javafx.scene.control.TableView.TableViewSelectionModel;
import javafx.scene.control.cell.ChoiceBoxTableCell;
import javafx.scene.control.cell.TextFieldTableCell;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
import javafx.util.Callback;
import javafx.util.StringConverter;

  class DBConnector {

    private static Connection conn;
    private static String url = "jdbc:mysql://localhost/test";
    private static String user = "root";
    private static String pass = "root";

    public static Connection connect() throws SQLException{
        try{
            Class.forName("com.mysql.jdbc.Driver").newInstance();
        }catch(ClassNotFoundException cnfe){
            System.err.println("Error: "+cnfe.getMessage());
        }catch(InstantiationException ie){
            System.err.println("Error: "+ie.getMessage());
        }catch(IllegalAccessException iae){
            System.err.println("Error: "+iae.getMessage());
        }

        conn = DriverManager.getConnection(url,user,pass);
        return conn;
    }
    public static Connection getConnection() throws SQLException, ClassNotFoundException{
        if(conn !=null && !conn.isClosed())
            return conn;
        connect();
        return conn;

    }
}
public class DynamicTable extends Application{
 Object newValue;
    //TABLE VIEW AND DATA
    private ObservableList<ObservableList> data;
    private TableView<ObservableList> tableview;

    //MAIN EXECUTOR
    public static void main(String[] args) {
        launch(args);
    }

    //CONNECTION DATABASE
    public void buildData(){
                        tableview.setEditable(true);
         Callback<TableColumn<Map, String>, TableCell<Map, String>>
            cellFactoryForMap = new Callback<TableColumn<Map, String>,
                TableCell<Map, String>>() {
                    @Override
                    public TableCell call(TableColumn p) {
                        return new TextFieldTableCell(new StringConverter() {
                            @Override
                            public String toString(Object t) {
                                return t.toString();
                            }
                            @Override
                            public Object fromString(String string) {
                                return string;
                            }                                    
                        });
                    }
        };
          Connection c ;
          data = FXCollections.observableArrayList();
          try{
            c = DBConnector.connect();
            //SQL FOR SELECTING ALL OF CUSTOMER
            String SQL = "SELECT * from CUSTOMer";
            //ResultSet
            ResultSet rs = c.createStatement().executeQuery(SQL);

            /**********************************
             * TABLE COLUMN ADDED DYNAMICALLY *
             **********************************/
            for(int i=0 ; i<rs.getMetaData().getColumnCount(); i++){
                //We are using non property style for making dynamic table
                final int j = i;                
                TableColumn col = new TableColumn(rs.getMetaData().getColumnName(i+1));






          if(j==1){
               final ObservableList<String> logLevelList = FXCollections.observableArrayList("FATAL", "ERROR", "WARN", "INFO", "INOUT", "DEBUG");
       col.setCellFactory(ChoiceBoxTableCell.forTableColumn(logLevelList));
            tableview.getColumns().addAll(col); 
          }
          else{
           col.setCellValueFactory(new Callback<CellDataFeatures<ObservableList,String>,ObservableValue<String>>(){                    
                    public ObservableValue<String> call(CellDataFeatures<ObservableList, String> param) {                                                                                              
                        return new SimpleStringProperty(param.getValue().get(j).toString());     


                    }                    
                });
            tableview.getColumns().addAll(col); 

          }
         if(j!=1)
        col.setCellFactory(cellFactoryForMap);


                System.out.println("Column ["+i+"] ");


            }


            /********************************
             * Data added to ObservableList *
             ********************************/
            while(rs.next()){
                //Iterate Row
                ObservableList<String> row = FXCollections.observableArrayList();
                for(int i=1 ; i<=rs.getMetaData().getColumnCount(); i++){
                    //Iterate Column
                    row.add(rs.getString(i));
                }
                System.out.println("Row [1] added "+row );
                data.add(row);

            }

            //FINALLY ADDED TO TableView
            tableview.setItems(data);
          }catch(Exception e){
              e.printStackTrace();
              System.out.println("Error on Building Data");             
          }
      }


      @Override
      public void start(Stage stage) throws Exception {
        //TableView


             Button showDataButton = new Button("Add");
        showDataButton.setOnAction(new EventHandler<ActionEvent>() {

                 public void handle(ActionEvent event) {

                     ObservableList<String> row = FXCollections.observableArrayList();

                for(int i=1 ; i<=3; i++){
                    //Iterate Column
                    row.add("asdasd");
                }
                 data.add(row);



            //FINALLY ADDED TO TableView
            tableview.setItems(data);
                 }
        });


        tableview = new TableView();
        buildData();

        //Main Scene
         BorderPane root = new BorderPane();
        root.setCenter(tableview);
        root.setBottom(showDataButton);
        Scene scene = new Scene(root,500,500);        

        stage.setScene(scene);
        stage.show();
         tableview.getSelectionModel().selectedItemProperty().addListener(new ChangeListener() {
            @Override
            public void changed(ObservableValue observableValue, Object oldValue, Object newValue) {
                //Check whether item is selected and set value of selected item to Label
                if (tableview.getSelectionModel().getSelectedItem() != null) {
                    TableViewSelectionModel selectionModel = tableview.getSelectionModel();
                    ObservableList selectedCells = selectionModel.getSelectedCells();
                    TablePosition tablePosition = (TablePosition) selectedCells.get(0);
                    Object val = tablePosition.getTableColumn().getCellData(newValue);
                    System.out.println("Selected Value " + val);
                    System.out.println("Selected row " + newValue);
       }
            }
        });


    }







    }

please help me..