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POHow to update a Pie Chart in Swing with embedded JavaFx applet - Null Point Exception
 

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  1. POHow to update a Pie Chart in Swing with embedded JavaFx applet - Null Point Exception
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    <p>I'm working on my final programming task for school and wanted to add a piece of little functional eye candy to my java application, in the form of a dynamic Pie Chart in JavaFx. </p> <p>Using Netbeans 7.2 rc2, I created a swing/javafx hybrid application from the templates. I extended the JPanelClass to create a shell with which my main application could use to access the FX features. The problem I'm facing, however is that while the initialisation of the chart goes smoothly, when I try to update the blasted thing, it generates a Null Pointer Exception. Here I believe is the pertinent code:</p> <p><em>Instantiation:</em></p> <pre><code>public class PieChartJFxPanel extends JApplet { private static final int JFXPANEL_WIDTH_INT = 500; private static final int JFXPANEL_HEIGHT_INT = 500; StackPane root = new StackPane(); PieChart athleteChart; ObservableList&lt;PieChart.Data&gt; pieChartData =FXCollections.observableArrayList(); private static JFXPanel fxContainer; private int fAthletes=0; private int rAthletes=0; public PieChartJFxPanel(int totalAthletes,int finishedAthletes){ super(); fAthletes=finishedAthletes; rAthletes=totalAthletes-fAthletes; } @Override public void init() { fxContainer = new JFXPanel(); fxContainer.setPreferredSize(new Dimension(JFXPANEL_WIDTH_INT, JFXPANEL_HEIGHT_INT)); add(fxContainer, BorderLayout.CENTER); // create JavaFX scene Platform.runLater(new Runnable() { @Override public void run() { createScene(); } }); } </code></pre> <p>The Scene Constructor:</p> <pre><code>private void createScene() { pieChartData.add(new PieChart.Data("Finished",fAthletes)); pieChartData.add(new PieChart.Data("Outstanding",rAthletes)); athleteChart=new PieChart(); athleteChart.setLegendVisible(false); athleteChart.setTitle("Race Status"); //athleteChart.setAnimated(true); athleteChart.setData(pieChartData); root.getChildren().add(athleteChart); fxContainer.setScene(new Scene(root)); // } </code></pre> <p>And the method which generated the exception:</p> <pre><code>public void setData(int total, int in){ final ObservableList&lt;PieChart.Data&gt; pieChartDat=FXCollections.observableArrayList(); pieChartDat.add(new PieChart.Data("Finished",fAthletes)); pieChartDat.add(new PieChart.Data("Outstanding",rAthletes)); athleteChart.setData(pieChartDat); } </code></pre> <p>And the exception:</p> <pre><code>Exception in thread "main" java.lang.NullPointerException at piechartjpanel.PieChartJFxPanel.setData(PieChartJFxPanel.java:95) at piechartjpanel.AthleteIOChart.setAthletes(AthleteIOChart.java:62) at piechartjpanel.Test.setter(Test.java:34) at piechartjpanel.Test.main(Test.java:48) </code></pre> <p>Any help is appreciated :) Thanks in advance</p>
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