Java SE (Java Platform, Standard Edition)

I have a line chart with 2 data series as under

 public static ObservableList<XYChart.Series<Double,Double>> lineChartData = FXCollections.observableArrayList(
            new LineChart.Series<Double,Double>("Series 1", FXCollections.observableArrayList(
                new XYChart.Data<Double,Double>(0.0, 1.0),
                new XYChart.Data<Double,Double>(1.2, 1.4),
                new XYChart.Data<Double,Double>(2.2, 1.9),
                new XYChart.Data<Double,Double>(2.7, 2.3),
                new XYChart.Data<Double,Double>(2.9, 0.5)
            )),
            new LineChart.Series<Double,Double>("Series 2", FXCollections.observableArrayList(
                new XYChart.Data<Double,Double>(2.0, 2.2)
            ))
        );

and I need to reset the data present at the zeroth index of the second data series i.e

 XYChart.Data<Double,Double>(2.0, 2.2)

needs to be reset to another x,y value dynamically on click of a button so in the button's action handler I am doing this

  lineChartData.get(1).getData().set(0, new XYChart.Data<Double,Double>(2.6, 2.0));

but unfortunately it is throwing a NullPointerException with JavaFX Beta b38 on my Win Vista machine

java.lang.NullPointerException
at javafx.scene.chart.LineChart.dataItemRemoved(LineChart.java:168)
at javafx.scene.chart.XYChart.dataItemsChanged(XYChart.java:306)
at javafx.scene.chart.XYChart.access$2500(XYChart.java:35)
at javafx.scene.chart.XYChart$Series$1.onChanged(XYChart.java:1111) 

I have filed a bug in the JavaFX Jira over here [http://javafx-jira.kenai.com/browse/RT-15291|http://javafx-jira.kenai.com/browse/RT-15291]

but it was closed as it was not reproducible at their end

I am not sure if there is any workaround for this, I tried clearing the list and adding a new value it works without any problem but it doesn't refresh the chart with the new value

Would like to know whether I am doing anything wrong, and also whether anyone else is facing the same issue or not ?

Below given is the sample program with which I am able to reproduce this issue on my system, execute it and click the reset button and check the stacktrace.

import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.control.Button;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

/**
 *
 * @author abhilshit
 */
public class ResetChartTest extends Application {
    
    public static ObservableList<XYChart.Series<Double,Double>> lineChartData = FXCollections.observableArrayList(
            new LineChart.Series<Double,Double>("Series 1", FXCollections.observableArrayList(
                new XYChart.Data<Double,Double>(0.0, 1.0),
                new XYChart.Data<Double,Double>(1.2, 1.4),
                new XYChart.Data<Double,Double>(2.2, 1.9),
                new XYChart.Data<Double,Double>(2.7, 2.3),
                new XYChart.Data<Double,Double>(2.9, 0.5)
            )),
            new LineChart.Series<Double,Double>("Series 2", FXCollections.observableArrayList(
                new XYChart.Data<Double,Double>(2.0, 2.2)
            ))
        );
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Application.launch(ResetChartTest.class, args);
    }
    
    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Reset");
        Group root = new Group();
        Scene scene = new Scene(root, 500, 450, Color.LIGHTGREEN);
        
        NumberAxis xAxis = new NumberAxis("X-Axis", 0, 3, 1);
        NumberAxis yAxis = new NumberAxis("Y-Axis", 0, 3, 1);
       
        LineChart chart = new LineChart(xAxis, yAxis, lineChartData);
        
        
        Button resetButton = new Button();
        resetButton.setText("Reset");
        resetButton.setLayoutX(400);
        resetButton.setLayoutY(350);
        resetButton.setOnAction(new EventHandler<ActionEvent>() {

            public void handle(ActionEvent event) {
                lineChartData.get(1).getData().set(0, new XYChart.Data<Double,Double>(2.6, 2.0));
            }
        });
        root.getChildren().
                addAll(chart,resetButton);        
        primaryStage.setScene(scene);
        primaryStage.setVisible(true);
    }
}

Would appreciate any help,suggestion or comments.

Thanks
Abhilshit