JFreeChart- Gantt Chart

A Gantt chart is a kind of bar chart which is commonly used for planning and scheduling project tasks and events.

The following images show some of the demo versions of gantt chart incorporated in JFreeChart library:

Gantt Chart Demo 1:

Gantt Chart Demo 2:

Gantt chart example:

Let us consider the following sample data for a Gantt chart.

Software Development Phases	Estimated Date		Actual date
Requirement	2017-07-03	2017-07-07	2017-07-03	2017-07-05
Design	2017-07-10	2017-07-14	2017-07-06	2017-07-17
Coding	2017-07-17	2017-07-21	2017-07-18	2017-07-27
Testing	2017-07-24	2017-07-28	2017-07-28	2017-08-01
Deployment	2017-07-31	2017-08-04	2017-08-02	2017-08-04

The following codes create a Gantt chart from the above sample data:

GanttChartExample.java

import java.time.LocalDate;
import java.time.ZoneOffset;
import java.util.Date;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.data.category.IntervalCategoryDataset;
import org.jfree.data.gantt.Task;
import org.jfree.data.gantt.TaskSeries;
import org.jfree.data.gantt.TaskSeriesCollection;

public class GanttChartExample extends JFrame {

   private static final long serialVersionUID = 1L;

   public GanttChartExample(String title) {
      super(title);
      // Create dataset
      IntervalCategoryDataset dataset = getCategoryDataset();
    
      // Create chart
      JFreeChart chart = ChartFactory.createGanttChart(
            "Gantt Chart Example", // Chart title
            "Software Development Phases", // X-Axis Label
            "Timeline", // Y-Axis Label
            dataset);

      ChartPanel panel = new ChartPanel(chart);
      setContentPane(panel);
   }

   private IntervalCategoryDataset getCategoryDataset() {

TaskSeries series1 = new TaskSeries("Estimated Date"); series1.add(new Task("Requirement",
Date.from(LocalDate.of(2017,7,3).atStartOfDay().toInstant(ZoneOffset.UTC)),
Date.from(LocalDate.of(2017, 7,7).atStartOfDay().toInstant(ZoneOffset.UTC))
         ));
      
 series1.add(new Task("Design",Date.from(LocalDate.of(2017, 7,10).atStartOfDay().toInstant(ZoneOffset.UTC)),
 Date.from(LocalDate.of(2017, 7, 14).atStartOfDay().toInstant(ZoneOffset.UTC))
         ));
      
 series1.add(new Task("Coding",Date.from(LocalDate.of(2017, 7,17).atStartOfDay().toInstant(ZoneOffset.UTC)),
 Date.from(LocalDate.of(2017, 7, 21).atStartOfDay().toInstant(ZoneOffset.UTC))
         ));
      
 series1.add(new Task("Testing", Date.from(LocalDate.of(2017, 7,24).atStartOfDay().toInstant(ZoneOffset.UTC)),
 Date.from(LocalDate.of(2017, 7, 28).atStartOfDay().toInstant(ZoneOffset.UTC))
         ));
      
 series1.add(new Task("Deployment", Date.from(LocalDate.of(2017, 07,31).atStartOfDay().toInstant(ZoneOffset.UTC)),
 Date.from(LocalDate.of(2017, 8, 4).atStartOfDay().toInstant(ZoneOffset.UTC))
         ));
      
      
TaskSeries series2 = new TaskSeries("Actual Date");
series2.add(new Task("Requirement",Date.from(LocalDate.of(2017, 7,3).atStartOfDay().toInstant(ZoneOffset.UTC)),
Date.from(LocalDate.of(2017, 7, 05).atStartOfDay().toInstant(ZoneOffset.UTC))
         ));
      
 series2.add(new Task("Design",
 Date.from(LocalDate.of(2017, 7, 6).atStartOfDay().toInstant(ZoneOffset.UTC)),
 Date.from(LocalDate.of(2017, 7, 17).atStartOfDay().toInstant(ZoneOffset.UTC))
         ));
      
 series2.add(new Task("Coding",
 Date.from(LocalDate.of(2017, 7, 18).atStartOfDay().toInstant(ZoneOffset.UTC)),
 Date.from(LocalDate.of(2017, 7, 27).atStartOfDay().toInstant(ZoneOffset.UTC))
         ));
      
 series2.add(new Task("Testing",
 Date.from(LocalDate.of(2017, 7, 28).atStartOfDay().toInstant(ZoneOffset.UTC)),
 Date.from(LocalDate.of(2017, 8, 1).atStartOfDay().toInstant(ZoneOffset.UTC))
         ));
      
 series2.add(new Task("Deployment",
 Date.from(LocalDate.of(2017, 8, 2).atStartOfDay().toInstant(ZoneOffset.UTC)),
 Date.from(LocalDate.of(2017, 8, 4).atStartOfDay().toInstant(ZoneOffset.UTC))
         ));

 TaskSeriesCollection dataset = new TaskSeriesCollection();
 dataset.add(series1);dataset.add(series2);
 return dataset;
   }

 public static void main(String[] args) {
 SwingUtilities.invokeLater(() -> {
 GanttChartExample example = new GanttChartExample("Gantt Chart Example");
         example.setSize(800, 400);
         example.setLocationRelativeTo(null);
         example.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
         example.setVisible(true);
      });
   }
}

Output: