利用JFreechart曲线图

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.servlet.ServletUtilities,org.jfree.chart.title.TextTitle,org.jfree.data.time.TimeSeries,org.jfree.data.time.Month,org.jfree.data.time.TimeSeriesCollection,java.awt.Font"%>
<%
	//访问量统计时间线
	TimeSeries timeSeries = new TimeSeries("曲线图", Month.class);
	//时间曲线数据集合
	TimeSeriesCollection lineDataset = new TimeSeriesCollection();
	//构造数据集合
	timeSeries.add(new Month(1, 2007), 11200);
	timeSeries.add(new Month(2, 2007), 9000);
	timeSeries.add(new Month(3, 2007), 6200);
	timeSeries.add(new Month(4, 2007), 8200);
	timeSeries.add(new Month(5, 2007), 8200);
	timeSeries.add(new Month(6, 2007), 12200);
	timeSeries.add(new Month(7, 2007), 13200);
	timeSeries.add(new Month(8, 2007), 8300);
	timeSeries.add(new Month(9, 2007), 12400);
	timeSeries.add(new Month(10, 2007), 12500);
	timeSeries.add(new Month(11, 2007), 13600);
	timeSeries.add(new Month(12, 2007), 12500);
	lineDataset.addSeries(timeSeries);
	JFreeChart chart = ChartFactory.createTimeSeriesChart("访问量统计时间线",
			"month", "visit amount", lineDataset, true, true, true);
	
	//设置子标题
	TextTitle subtitle = new TextTitle("2007年度", new Font("黑体",
			Font.BOLD, 12));
	chart.addSubtitle(subtitle);
	//设置主标题
	chart.setTitle(new TextTitle("曲线图", new Font("隶书",
			Font.ITALIC, 15)));
	chart.setAntiAlias(true);
	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 %>">