利用JFreechart绘制复杂柱状图(二)

web.xml

<?xml version="1.0"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
	<servlet>
		<servlet-name>DisplayChart</servlet-name>
		<servlet-class>org.jfree.chart.servlet.DisplayChart</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>DisplayChart</servlet-name>
		<url-pattern>/DisplayChart</url-pattern>
	</servlet-mapping>
</web-app>

demo.jsp

<%@ page contentType="text/html;charset=GBK"%>

<%@ page
	import="org.jfree.chart.ChartFactory,org.jfree.chart.JFreeChart,org.jfree.chart.plot.PlotOrientation,org.jfree.chart.servlet.ServletUtilities,org.jfree.data.category.CategoryDataset,org.jfree.data.general.DatasetUtilities"%>

<%
	double[][] data = new double[][] { { 1310, 1220, 1110, 1000 },
			{ 720, 700, 680, 640 }, { 1130, 1020, 980, 800 },
			{ 440, 400, 360, 300 } };
	String[] rowKeys = { "pig", "beef", "chicken", "fish" };

	String[] columnKeys = { "Guangzhou", "Shenzhen", "Dongguan",
			"Foshan" };
	CategoryDataset dataset = DatasetUtilities.createCategoryDataset(
			rowKeys, columnKeys, data);
	JFreeChart chart = ChartFactory.createBarChart3D("JFreeChart Demo",
			"type", "amount", dataset, PlotOrientation.VERTICAL, true,
			false, false);
	String filename = ServletUtilities.saveChartAsPNG(chart, 500, 300,
			null, session);
	String graphURL = request.getContextPath()
			+ "/DisplayChart?filename=" + filename;
%>
<img src="<%=graphURL%>" width=500 height=300 border=0
	usemap="#<%= filename %>">