84. BarChart

In a BarChart, the x-axis has to be categorical (and a String).

The relative heights of each category is plotted for all series. We make class changes and a few name changes.

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package ex84;

import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.chart.BarChart;
import javafx.scene.chart.CategoryAxis;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.chart.XYChart.Series;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
 
public class Ex84 extends Application {
 
    ObservableList<XYChart.Series<String, Double>> obList 
            = FXCollections.observableArrayList();
    
    public static void main(String[] args) {
        launch(args);
    }
 
    @Override
    public void start(Stage primaryStage) {
        CategoryAxis xAxis = new CategoryAxis();
        NumberAxis yAxis = new NumberAxis();
        initData();
        BarChart barChart = new BarChart(xAxis, yAxis, obList);
        barChart.setTitle("A bar plot");
        
        StackPane root = new StackPane();
        root.getChildren().add(barChart);
        
        primaryStage.setTitle("Example 84. BarChart");
        primaryStage.setScene(new Scene(root, 400, 250));
        primaryStage.show();
    }
 
    private void initData() {
        Series series1 = new Series<>();
        Series series2 = new Series<>();
        series1.getData().addAll(
                new XYChart.Data("0", 5),
                new XYChart.Data("1", 3),
                new XYChart.Data("2", 2)
                );
        series1.setName("series 1");
        series2.getData().addAll(
                new XYChart.Data("0", 2),
                new XYChart.Data("1", 4),
                new XYChart.Data("2", 7)
                );
        series2.setName("series 2");
        obList.addAll(series1, series2);
    }
}

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This is the output:

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