PieChart.dataProperty() has the following syntax.
public final ObjectProperty < ObservableList < PieChart.Data >> dataProperty()
In the following code shows how to use PieChart.dataProperty() method.
/*from w ww . j av a 2s . c om*/ import javafx.application.Application; import javafx.collections.FXCollections; import javafx.collections.ObservableList; import javafx.geometry.Side; import javafx.scene.Scene; import javafx.scene.chart.PieChart; import javafx.scene.chart.PieChart.Data; import javafx.scene.layout.StackPane; import javafx.stage.Stage; public class Main extends Application { public static void main(String[] args) { launch(args); } @Override public void start(Stage primaryStage) { PieChart pieChart = new PieChart(); pieChart.setData(getChartData()); System.out.println(pieChart.dataProperty()); pieChart.setTitle("Title"); pieChart.setLegendSide(Side.LEFT); pieChart.setClockwise(false); pieChart.setLabelsVisible(false); StackPane root = new StackPane(); root.getChildren().add(pieChart); primaryStage.setScene(new Scene(root, 300, 250)); primaryStage.show(); } private ObservableList<Data> getChartData() { ObservableList<Data> answer = FXCollections.observableArrayList(); answer.addAll(new PieChart.Data("java", 17.56), new PieChart.Data("JavaFx",31.37 ) ); return answer; } }