JavaFX - Stacked Bar Chart

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StackedBarChart is a variation of a BarChart, which plots bars indicating data values for a category. The bars can be vertical or horizontal depending on which axis is the category axis. The bar for each series is stacked on top of the previous series.

The following is a Stacked Bar Chart, which depicts the population growth.

Stacked Bar Chart in JavaFX

In JavaFX, a Stacked Bar Chart is represented by a class named StackedBarChart. This class belongs to the package javafx.scene.chart. By instantiating this class, you can create a StackedBarChart node in JavaFX.

To generate a Stacked Bar Chart in JavaFX, follow the steps given below.

Step 1: Defining the Axis

Define the X and Y axis of the stacked bar chart and set labels to them. In our example, X axis represents the continents and the y axis represents the population in millions.

public class ClassName extends Application { 
   @Override     
   public void start(Stage primaryStage) throws Exception {
      //Defining the x axis               
      CategoryAxis xAxis = new CategoryAxis();    

      xAxis.setCategories(FXCollections.<String>observableArrayList(Arrays.asList
      ("Africa", "America", "Asia", "Europe", "Oceania"))); 
      xAxis.setLabel("category");  

      //Defining the y axis 
      NumberAxis yAxis = new NumberAxis(); 
      yAxis.setLabel("Population (In millions)");
   }    
}

Step 2: Creating the Stacked Bar Chart

Create a line chart by instantiating the class named StackedBarChart of the package javafx.scene.chart. To the constructor of this class, pass the objects representing the X and Y axis created in the previous step.

//Creating the Bar chart 
StackedBarChart<String, Number> stackedBarChart = 
new StackedBarChart<>(xAxis, yAxis);         
stackedBarChart.setTitle("Historic World Population by Region"); 

Step 3: Preparing the Data

Instantiate the XYChart.Series class and add the data (a series of, x and y coordinates) to the Observable list of this class as follows −

//Prepare XYChart.Series objects by setting data 
XYChart.Series<String, Number> series1 = new XYChart.Series<>(); 
series1.setName("1800"); 
series1.getData().add(new XYChart.Data<>("Africa", 107)); 
series1.getData().add(new XYChart.Data<>("America", 31)); 
series1.getData().add(new XYChart.Data<>("Asia", 635)); 
series1.getData().add(new XYChart.Data<>("Europe", 203)); 
series1.getData().add(new XYChart.Data<>("Oceania", 2)); 
XYChart.Series<String, Number> series2 = new XYChart.Series<>();  

series2.setName("1900"); 
series2.getData().add(new XYChart.Data<>("Africa", 133)); 
series2.getData().add(new XYChart.Data<>("America", 156)); 
series2.getData().add(new XYChart.Data<>("Asia", 947)); 
series2.getData().add(new XYChart.Data<>("Europe", 408)); 
series1.getData().add(new XYChart.Data<>("Oceania", 6));  

XYChart.Series<String, Number> series3 = new XYChart.Series<>(); 
series3.setName("2008"); 
series3.getData().add(new XYChart.Data<>("Africa", 973)); 
series3.getData().add(new XYChart.Data<>("America", 914)); 
series3.getData().add(new XYChart.Data<>("Asia", 4054)); 
series3.getData().add(new XYChart.Data<>("Europe", 732)); 
series1.getData().add(new XYChart.Data<>("Oceania", 34));

Step 4: Add Data to the Stacked Bar Chart

Add the data series prepared in the previous step to the bar chart as follows −

//Setting the data to bar chart        
stackedBarChart.getData().addAll(series1, series2, series3); 

Step 5: Creating a Group Object

In the start() method, create a group object by instantiating the class named Group. This belongs to the package javafx.scene.

Pass the StackedBarChart (node) object created in the previous step as a parameter to the constructor of the Group class. This should be done in order to add it to the group as follows −

Group root = new Group(stackedBarChart); 

Step 6: Launching Application

Lastly, follow the given steps below to launch the application properly −

• Firstly, instantiate the class named Scene by passing the Group object as a parameter value to its constructor. To this constructor, you can also pass dimensions of the application screen as optional parameters.

• Then, set the title to the stage using the setTitle() method of the Stage class.

• Now, a Scene object is added to the stage using the setScene() method of the class named Stage.

• Display the contents of the scene using the method named show().

• Lastly, the application is launched with the help of the launch() method.

Example

The following table lists out the population in various continents in the years 1800, 1900 and 2008.

Following is a Java program that generates a stacked bar chart depicting the above data, using JavaFX.

Save this code in a file with the name StackedBarChartExample.java.

import java.util.Arrays; 
import javafx.application.Application; 
import javafx.collections.FXCollections; 
import javafx.scene.Group; 
import javafx.scene.Scene; 
import javafx.scene.chart.CategoryAxis; 
import javafx.stage.Stage; 
import javafx.scene.chart.NumberAxis; 
import javafx.scene.chart.StackedBarChart; 
import javafx.scene.chart.XYChart; 
         
public class StackedBarChartExample extends Application { 
   @Override 
   public void start(Stage stage) {     
      //Defining the axes               
      CategoryAxis xAxis = new CategoryAxis();    
      xAxis.setCategories(FXCollections.<String>observableArrayList(Arrays.asList
         ("Africa", "America", "Asia", "Europe", "Oceania"))); 
      
      xAxis.setLabel("category");
      NumberAxis yAxis = new NumberAxis(); 
      yAxis.setLabel("Population (In millions)");    
         
      //Creating the Bar chart 
      StackedBarChart<String, Number> stackedBarChart = 
         new StackedBarChart<>(xAxis, yAxis);         
      stackedBarChart.setTitle("Historic World Population by Region"); 
         
      //Prepare XYChart.Series objects by setting data 
      XYChart.Series<String, Number> series1 = new XYChart.Series<>();  
      series1.setName("1800"); 
      series1.getData().add(new XYChart.Data<>("Africa", 107)); 
      series1.getData().add(new XYChart.Data<>("America", 31));  
      series1.getData().add(new XYChart.Data<>("Asia", 635)); 
      series1.getData().add(new XYChart.Data<>("Europe", 203)); 
      series1.getData().add(new XYChart.Data<>("Oceania", 2)); 
         
      XYChart.Series<String, Number> series2 = new XYChart.Series<>(); 
      series2.setName("1900"); 
      series2.getData().add(new XYChart.Data<>("Africa", 133)); 
      series2.getData().add(new XYChart.Data<>("America", 156)); 
      series2.getData().add(new XYChart.Data<>("Asia", 947)); 
      series2.getData().add(new XYChart.Data<>("Europe", 408)); 
      series1.getData().add(new XYChart.Data<>("Oceania", 6));  
     
      XYChart.Series<String, Number> series3 = new XYChart.Series<>(); 
      series3.setName("2008"); 
      series3.getData().add(new XYChart.Data<>("Africa", 973)); 
      series3.getData().add(new XYChart.Data<>("America", 914)); 
      series3.getData().add(new XYChart.Data<>("Asia", 4054)); 
      series3.getData().add(new XYChart.Data<>("Europe", 732)); 
      series1.getData().add(new XYChart.Data<>("Oceania", 34)); 
         
      //Setting the data to bar chart
      stackedBarChart.getData().addAll(series1, series2, series3); 
         
      //Creating a Group object  
      Group root = new Group(stackedBarChart); 
         
      //Creating a scene object 
      Scene scene = new Scene(root, 600, 400);  
      
      //Setting title to the Stage 
      stage.setTitle("stackedBarChart"); 
         
      //Adding scene to the stage 
      stage.setScene(scene); 
         
      //Displaying the contents of the stage 
      stage.show();         
   } 
   public static void main(String args[]){ 
      launch(args); 
   } 
}

Compile and execute the saved java file from the command prompt using the following commands.

javac --module-path %PATH_TO_FX% --add-modules javafx.controls StackedBarChartExample.java 
java --module-path %PATH_TO_FX% --add-modules javafx.controls StackedBarChartExample 

Output

On executing, the above program generates a JavaFX window displaying an area chart as shown below.

Example

The following table depicts the data of employees laid off and recruited in an organization, in the first quarter of an year.

Following is a Java program that generates a stacked bar chart depicting the above data, using JavaFX.

Save this code in a file with the name StackedBarChartEmployees.java.

import javafx.application.Application; 
import javafx.scene.Group; 
import javafx.scene.Scene; 
import javafx.scene.chart.StackedBarChart; 
import javafx.scene.chart.CategoryAxis; 
import javafx.stage.Stage; 
import javafx.scene.chart.NumberAxis; 
import javafx.scene.chart.XYChart; 
         
public class StackedBarChartEmployees extends Application { 
   @Override 
   public void start(Stage stage) {     
      //Defining the X axis               
      CategoryAxis xAxis = new CategoryAxis();  
           
      //defining the y Axis 
      NumberAxis yAxis = new NumberAxis(); 
      yAxis.setLabel("Number of Employees");  
      
      //Creating the Area chart 
      StackedBarChart stackedbarChart = new StackedBarChart(xAxis, yAxis);
      stackedbarChart.setTitle("Employees Recruitment to Lay off ratio");        
         
      //Prepare XYChart.Series objects by setting data  
      XYChart.Series series1 = new XYChart.Series();  
      series1.setName("Employees Laid Off"); 
      series1.getData().add(new XYChart.Data("January", 30)); 
      series1.getData().add(new XYChart.Data("February", 12)); 
      series1.getData().add(new XYChart.Data("March", 31)); 
      series1.getData().add(new XYChart.Data("April", 52)); 
      series1.getData().add(new XYChart.Data("May", 4));
      series1.getData().add(new XYChart.Data("June", 10));  
                         
      XYChart.Series series2 = new XYChart.Series(); 
      series2.setName("Employees Recruited"); 
      series2.getData().add(new XYChart.Data("January", 12)); 
      series2.getData().add(new XYChart.Data("February", 54)); 
      series2.getData().add(new XYChart.Data("March", 24)); 
      series2.getData().add(new XYChart.Data("April", 32)); 
      series2.getData().add(new XYChart.Data("May", 43)); 
      series2.getData().add(new XYChart.Data("June", 5));        
                
      //Setting the XYChart.Series objects to stacked bar chart        
      stackedbarChart.getData().addAll(series1,series2); 
         
      //Creating a Group object  
      Group root = new Group(stackedbarChart); 
         
      //Creating a scene object 
      Scene scene = new Scene(root, 600, 400);  
      
      //Setting title to the Stage 
      stage.setTitle("Stacked Bar Chart"); 
         
      //Adding scene to the stage 
      stage.setScene(scene); 
         
      //Displaying the contents of the stage 
      stage.show();         
   } 
   public static void main(String args[]){ 
      launch(args);
   }
}

Compile and execute the saved java file from the command prompt using the following commands.

javac --module-path %PATH_TO_FX% --add-modules javafx.controls StackedBarChartEmployees.java 
java --module-path %PATH_TO_FX% --add-modules javafx.controls StackedBarChartEmployees

Output

On executing, the above program generates a JavaFX window displaying an area chart as shown below.