pie3ddemo.java

jfreechart不错的教程例子谢谢!

package com.segsec.chart.data;

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.PrintWriter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartRenderingInfo;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.entity.StandardEntityCollection;
import org.jfree.chart.plot.PiePlot;
import org.jfree.chart.urls.StandardPieURLGenerator;
import org.jfree.data.general.DefaultPieDataset;

public class Pie3DDemo {
	private DefaultPieDataset getDataset() {
		// categories...
		String[] section = new String[] { "Jan", "Feb", "Mar", "Apr", "May",
				"Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
		// data...
		double[] data = new double[section.length];
		for (int i = 0; i < data.length; i++) {
			data[i] = 10 + (Math.random() * 10);
		}
		// create the dataset...
		DefaultPieDataset dataset = new DefaultPieDataset();
		for (int i = 0; i < data.length; i++) {
			dataset.setValue(section[i], data[i]);
		}
		return dataset;
	}

	public String getChartViewer(HttpServletRequest request,
			HttpServletResponse response) {
		DefaultPieDataset dataset = getDataset();
		// create the chart...
		JFreeChart chart = ChartFactory.createPieChart3D("Pie3D Chart Demo", // chart title
				dataset, // data
				true, // include legend
				true, false);
		// set the background color for the chart...
		chart.setBackgroundPaint(Color.cyan);
		PiePlot plot = (PiePlot) chart.getPlot();
		plot.setNoDataMessage("No data available");
		// set drilldown capability...
		plot.setURLGenerator(new StandardPieURLGenerator("Bar3DDemo.jsp","section"));
		plot.setLabelGenerator(null);
		// OPTIONAL CUSTOMISATION COMPLETED.
		ChartRenderingInfo info = null;
		HttpSession session = request.getSession();
		try {
			// Create RenderingInfo object
			response.setContentType("text/html");
			info = new ChartRenderingInfo(new StandardEntityCollection());
			BufferedImage chartImage = chart.createBufferedImage(640, 400, info);
			// putting chart as BufferedImage in session,
			// thus making it available for the image reading action Action.
			session.setAttribute("chartImage", chartImage);
			PrintWriter writer = new PrintWriter(response.getWriter());
			ChartUtilities.writeImageMap(writer, "imageMap", info,true);    
			writer.flush();
		} catch (Exception e) {
		}

		String pathInfo = "http://";
		pathInfo += request.getServerName();
		int port = request.getServerPort();
		pathInfo += ":" + String.valueOf(port);
		pathInfo += request.getContextPath();
		String chartViewer = pathInfo + "/servlet/ChartViewerServlet";
		return chartViewer;
	}
}