Look attantively on the attached image.

You can see corners: bars are oriented in a wrong way.

You can easily reproduce this with the code:


import java.util.Random;
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.chart.*;
import javafx.scene.control.ToggleButton;
import javafx.scene.layout.Pane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class JavaCharts extends Application {

    public static void main(String[] args) {
        launch(args);
    }
    NumberAxis axisY = new NumberAxis(0, 100, 10);
    ObservableList<String> existingCategories = FXCollections.observableArrayList();
    CategoryAxis axisX = new CategoryAxis(existingCategories);
    StackedBarChart testedBarChart = new StackedBarChart(axisY, axisX);
    VBox vb = new VBox();

    @Override
    public void start(Stage stage) throws Exception {
        testedBarChart.setTitle("BarChart");
        testedBarChart.setStyle("-fx-border-color: darkgray;");
        existingCategories.addAll("category1", "category2", "category3");

        addData();

        Pane pane = new Pane();
        pane.setPrefSize(600, 600);

        pane.setPrefSize(600, 600);
        pane.getChildren().add(testedBarChart);

        ToggleButton tb = new ToggleButton("Press me");
        tb.selectedProperty().bindBidirectional(axisY.autoRangingProperty());

        ToggleButton tb1 = new ToggleButton("Unpress me");
        tb1.selectedProperty().bindBidirectional(axisX.tickMarkVisibleProperty());

        vb.getChildren().addAll(pane, tb, tb1);

        Scene scene = new Scene(vb, 700, 700);
        stage.setScene(scene);
        stage.show();
    }

    public void addData() {

        String serieName = "Serie";
        double min = 0;
        double max = 100;
        int amount = 3;

        ObservableList list = FXCollections.observableArrayList();

        XYChart.Series serie = new XYChart.Series(serieName, list);

        for (int i = 0; i < amount; i++) {
            XYChart.Data newData = new XYChart.Data();
            String category = existingCategories.get(i);
            Double value = new Random().nextDouble() * (max - min) + min;
            newData.setYValue(category);
            newData.setXValue(value);
            list.add(newData);
            System.out.println(newData + " to category " + category + " value " + value);
        }

        testedBarChart.getData().add(serie);
    }
}

just launch it.