Bar Chart
In this section we are providing you an example to create a
Bar Chart.
Description of Program
For creating a Bar chart we use the object of DefaultCategoryDataset. After creating the object of DefaultCategoryDataset we add some data in this object by invoking
setValue() method. In this example you learn some more interactive features of
JFreechart like set the background color of chart and adjust the color the title
etc.
Description of Code
For defining a dataset for a Bar chart we have to create an object of DefaultCategoryDataset type :
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
After creating the instance of dataset then we have to add the data in the data set by invoking the method
setValue().
setValue(6, “Marks”, “Rahul”);
First argument specifies the total marks obtained by the student and the second argument specify what will appear in the legend to the meaning of the bar.
JFreeChart chart = ChartFactory.createBarChart("BarChart using JFreeChart", "Student", "Marks", dataset, PlotOrientation.VERTICAL, true,
true, false);
After added the data in dataset we create the Bar chart by invoking the createBarChart()
method. This method is a static method of ChartFactory class and its returns the object of JFreeChart type.This method syntax is:
Public static JFreeChart createBarChart(java.lang.String title, java.lang.String categoryAxisLabel, java.lang.String valueAxisLabel, CategoryDataset dataset,
PlotOrientation orientation, boolean legend, boolean tooltips, boolean urls);
chart.setBackgroundPaint(Color.yellow);
Above method is used to set the color of chart background
chart.getTitle().setPaint(Color.blue);
Above method is used to set the color of chart title
CategoryPlot p = chart.getCategoryPlot();
Above method is used to get the object of the Plot for Bar Chart
p.setRangeGridlinePaint(Color.red);
Above method is used to set the color of plot Gridlines
ChartFrame frame1=new ChartFrame("Bar Chart",chart);
After this we create the object of ChartFrame. It used to display a chart.
Here is code of Program :
import org.jfree.chart.*;
import org.jfree.data.category.*;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.xy.*;
import org.jfree.data.*;
import org.jfree.chart.renderer.category.*;
import org.jfree.chart.plot.*;
import java.awt.*;
public class BarExample1{
public static void main(String arg[]){
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
dataset.setValue(2, "Marks", "Rahul");
dataset.setValue(7, "Marks", "Vinod");
dataset.setValue(4, "Marks", "Deepak");
dataset.setValue(9, "Marks", "Prashant");
dataset.setValue(6, "Marks", "Chandan");
JFreeChart chart = ChartFactory.createBarChart
("BarChart using JFreeChart","Student", "Marks", dataset,
PlotOrientation.VERTICAL, false,true, false);
chart.setBackgroundPaint(Color.yellow);
chart.getTitle().setPaint(Color.blue);
CategoryPlot p = chart.getCategoryPlot();
p.setRangeGridlinePaint(Color.red);
ChartFrame frame1=new ChartFrame("Bar
Chart",chart);
frame1.setVisible(true);
frame1.setSize(400,350);
}
}
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Output of the Program :
Download this Example
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