how to change pie chart colors of JFreeChart? - jfreechart

Question

how to customize the colors of JFreeChart graphic.
lets see my java code :
private StreamedContent chartImage ;
public void init(){
JFreeChart jfreechart = ChartFactory.createPieChart("title", createDataset(), true, true, false);
File chartFile = new File("dynamichart");
ChartUtilities.saveChartAsPNG(chartFile, jfreechart, 375, 300);
chartImage = new DefaultStreamedContent(new FileInputStream( chartFile), "image/png");
}
public PieDataset createDataset() {
DefaultPieDataset dataset = new DefaultPieDataset();
dataset.setValue("J-2", 10);
dataset.setValue("J-1", 15);
dataset.setValue("J", 50);
dataset.setValue("J+1", 20);
dataset.setValue("J+2", 15);
return dataset;
}
html page :
<p:graphicImage id="MyImage" value="#{beanCreateImage.chartImage}" />

Answer 1

You can change the color of single pieces like this:
JFreeChart chart = ChartFactory.createPieChart("title", createDataset(), true, true, false);
PiePlot plot = (PiePlot) chart.getPlot();
plot.setSectionPaint("J+1", Color.black);
plot.setSectionPaint("J-1", new Color(120, 0, 120));
// or do this, if you are using an older version of JFreeChart:
//plot.setSectionPaint(1, Color.black);
//plot.setSectionPaint(3, new Color(120, 0, 120));
So with your code, all the pies are colored automatically, after my code changes, the J-1 and J+1 have a fixed color, the rest gets automatically colored.

Answer 2

To set the colous for a chart you can implement the DrawingSupplier inferface in this case I've used DefaultDrawingSupplier:
public class ChartDrawingSupplier extends DefaultDrawingSupplier {
public Paint[] paintSequence;
public int paintIndex;
public int fillPaintIndex;
{
paintSequence = new Paint[] {
new Color(227, 26, 28),
new Color(000,102, 204),
new Color(102,051,153),
new Color(102,51,0),
new Color(156,136,48),
new Color(153,204,102),
new Color(153,51,51),
new Color(102,51,0),
new Color(204,153,51),
new Color(0,51,0),
};
}
#Override
public Paint getNextPaint() {
Paint result
= paintSequence[paintIndex % paintSequence.length];
paintIndex++;
return result;
}
#Override
public Paint getNextFillPaint() {
Paint result
= paintSequence[fillPaintIndex % paintSequence.length];
fillPaintIndex++;
return result;
}
}
Then include this code in your `init()' method
JFreeChart jfreechart = ChartFactory.createPieChart("title", createDataset(), true, true, false);
Plot plot = jfreechart.getPlot();
plot.setDrawingSupplier(new ChartDrawingSupplier());
...

Answer 3

You can customize the colors according to the labels while getting the data from the dataset:
// Add custom colors
PiePlot plot = (PiePlot) chart.getPlot();
for (int i = 0; i < dataset.getItemCount(); i++) {
if(dataset.getKey(i).equals("J+1")){
plot.setSectionPaint(i, Color.black);
}
}
You can also use a switch-case statement or the one you prefer.