Create Gantt Chart Using JFreeChart

Create Gantt Chart Using JFreeChart explains about creating a simple gantt chart using JFreechart API

A Gantt chart is a type of bar chart that illustrates a project schedule, named after their inventor, Henry Gantt (1861–1919), who designed such a chart around the years 1910–1915. Modern Gantt charts also show the dependency relationships between activities and current schedule status.

Reference -> https://en.wikipedia.org/wiki/Gantt_chart

How To Create Gantt Chart Using JFreeChart library?

JFreeChart is a free and open source java chart library used for creating professional quality charts. JFreeChart is purely written in java language, we can very easily incorporate JFreeChart in our java standalone and web applications.

Referenece - > http://www.jfree.org/jfreechart/

Here I am showing an example about How to create  a simple Gantt Chart using JFreeChart.

Required Libraries

pom.xml

<dependency>
	<groupId>org.jfree</groupId>
	<artifactId>jfreechart</artifactId>
	<version>1.5.0</version>
</dependency>
<dependency>
	<groupId>org.jfree</groupId>
	<artifactId>jcommon</artifactId>
	<version>1.0.24</version>
</dependency>

We can create following professional quality charts by using jfreechart.

• Single valued Charts such as compass, speedometer, thermometer
• Line Chart
• Pie Chart
• Bar Chart
• Bubble Chart
• Wind Chart
• Polar Chart

JFreeChart Example(Gantt Chart)

import java.time.LocalDate;
import java.time.ZoneOffset;
import java.util.Date;

import javax.swing.JFrame;

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 JFreeChartGanttChartExample extends JFrame {

    private static final long serialVersionUID = 1L;

    public JFreeChartGanttChartExample(String applicationTitle, String chartTitle) {
	super(applicationTitle);

	// based on the dataset we create the chart
	JFreeChart chart = ChartFactory.createGanttChart(chartTitle, "Development", "Time", createDataset(),
		 true, true, true);

	// Adding chart into a chart panel
	ChartPanel chartPanel = new ChartPanel(chart);

	// settind default size
	chartPanel.setPreferredSize(new java.awt.Dimension(500, 270));

	// add to contentPane
	setContentPane(chartPanel);
    }

    private IntervalCategoryDataset createDataset() {

	TaskSeriesCollection dataset = new TaskSeriesCollection();
	TaskSeries expected = new TaskSeries("Expected Date");
	expected.add(new Task("Analysis", Date.from(LocalDate.of(2018, 9, 5).atStartOfDay().toInstant(ZoneOffset.UTC)),
		Date.from(LocalDate.of(2018, 9, 8).atStartOfDay().toInstant(ZoneOffset.UTC))));

	expected.add(new Task("Design", Date.from(LocalDate.of(2018, 9, 12).atStartOfDay().toInstant(ZoneOffset.UTC)),
		Date.from(LocalDate.of(2018, 9, 16).atStartOfDay().toInstant(ZoneOffset.UTC))));

	expected.add(
		new Task("Development", Date.from(LocalDate.of(2018, 9, 19).atStartOfDay().toInstant(ZoneOffset.UTC)),
			Date.from(LocalDate.of(2018, 9, 23).atStartOfDay().toInstant(ZoneOffset.UTC))));

	expected.add(new Task("Testing", Date.from(LocalDate.of(2018, 9, 26).atStartOfDay().toInstant(ZoneOffset.UTC)),
		Date.from(LocalDate.of(2018, 9, 29).atStartOfDay().toInstant(ZoneOffset.UTC))));

	dataset.add(expected);
	
	TaskSeries actual = new TaskSeries("Actual Date");
	actual.add(
		new Task("Analysis", Date.from(LocalDate.of(2018, 9, 5).atStartOfDay().toInstant(ZoneOffset.UTC)),
			Date.from(LocalDate.of(2018, 9, 7).atStartOfDay().toInstant(ZoneOffset.UTC))));

	actual.add(new Task("Design", Date.from(LocalDate.of(2018, 9, 8).atStartOfDay().toInstant(ZoneOffset.UTC)),
		Date.from(LocalDate.of(2018, 9, 19).atStartOfDay().toInstant(ZoneOffset.UTC))));

	actual.add(new Task("Development", Date.from(LocalDate.of(2018, 9, 20).atStartOfDay().toInstant(ZoneOffset.UTC)),
		Date.from(LocalDate.of(2018, 9, 28).atStartOfDay().toInstant(ZoneOffset.UTC))));

	actual.add(new Task("Testing", Date.from(LocalDate.of(2018, 9, 28).atStartOfDay().toInstant(ZoneOffset.UTC)),
		Date.from(LocalDate.of(2018, 10, 3).atStartOfDay().toInstant(ZoneOffset.UTC))));
        dataset.add(actual);


	return dataset;

    }

    public static void main(String[] args) {
	JFreeChartGanttChartExample chart = new JFreeChartGanttChartExample("Gantt Chart Example",
		"Software Development Phase?");
	chart.pack();
	chart.setVisible(true);
    }
}

Output