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code { font-size:12px; font-family:verdana; color:509050;letter-spacing:0px;line-height:16px;}input { font-size:12px; font-family:verdana; color: 000000; background-color: FFFFFF}.copyright { font-size:10px; font-family:verdana; color:303030;letter-spacing:0px;line-height:16px;}.list { font-size:10px; font-family:verdana; color:202020; }作者：王恩建来源：http://www.sentom.net申明：未经作者同意，谢绝转载JFreeChart，开放源码的Java图表生成组件（基于LGPL Licence），可以创建饼图、 曲线图、柱状图、甘特图，生成PNG,JPG等图片格式文件。当前最新版本为0.9.11，右边是一张JFreeChart生成 的统计图。本文讲解如何在Web利用JFreeChart生成饼状统计图。一 安装配置
当前最新版本为0.9.11下载jfreechart-0 .9.11.zip 下载jfreechar t-0.9.11.tar.gz
解压缩文件，jfreechart-0.9.11目录下的jfreechart-0.9.11.jar和 lib/jcommon-0.8.6.jar,lib/gnujaxp.jar都是开发运行需要的文件，把这三个文件放置到应用的lib目录下。
然后在web.xml文件中增加以下内容：

      DisplayChart    org.jfree.chart.servlet.DisplayChart  

安装配置完成，现在可以写程序生成我们需要的统计图了。

二 开始，在JSP中生成饼型统计图

<%@ page contentType="text/html;charset=GBK"%><%@ page import="org.jfree.data.DefaultPieDataset"%><%@ page import="org.jfree.chart.JFreeChart"%><%@ page import="org.jfree.chart.plot.PiePlot"%><%@ page import="org.jfree.chart.ChartRenderingInfo"%><%@ page import="org.jfree.chart.servlet.ServletUtilities"%><%@ page import="org.jfree.chart.urls.StandardPieURLGenerator"%><%@ page import="org.jfree.chart.entity.StandardEntityCollection"%><%DefaultPieDataset data = new DefaultPieDataset();data.setValue("六月",500);data.setValue("七月",580);data.setValue("八月",828); PiePlot plot = new PiePlot(data);JFreeChart chart = new JFreeChart("",JFreeChart.DEFAULT_TITLE_FONT, plot, true);chart.setBackgroundPaint(java.awt.Color.white);//可选，设置图片背景色chart.setTitle("www.SenTom.net 网站访问统计表");//可选，设置图片标题ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());//500是图片长度，300是图片高度String filename = ServletUtilities.saveChartAsPNG(chart, 500, 300, info, session);String graphURL = request.getContextPath() + "/servlet/DisplayChart?filename=" + filename; %>       
       

就这么简单，生成的饼状图如下


三 高级，JSP+JAVABEAN生成饼状统计图
WebChart.java

/* * Created on 2003-9-9 * http://www.sentom.net * To change the template for this generated file go to * Window>Preferences>Java>Code Generation>Code and Comments */package net.sentom.chart;import java.awt.Insets;import java.awt.Font;import java.io.PrintWriter;import javax.servlet.http.HttpSession;import org.jfree.data.*;import org.jfree.chart.*;import org.jfree.chart.plot.*;import org.jfree.chart.entity.*;import org.jfree.chart.urls.*;import org.jfree.chart.servlet.*;import org.jfree.chart.labels.StandardPieToolTipGenerator;/** * @author sentom * * To change the template for this generated type comment go to * Window>Preferences>Java>Code Generation>Code and Comments */public class WebChart {private DefaultPieDataset data = new DefaultPieDataset();public void setValue(String key,double value){data.setValue(key,value);}public String generatePieChart(String title, HttpSession session, PrintWriter pw) {String filename = null;try {//创建chart对象PiePlot plot = new PiePlot(data);plot.setInsets(new Insets(0, 5, 5, 5));//在统计图片上建连结plot.setURLGenerator(new StandardPieURLGenerator("link.jsp","section"));plot.setToolTipGenerator(new StandardPieToolTipGenerator());JFreeChart chart = new JFreeChart("", JFreeChart.DEFAULT_TITLE_FONT, plot, true);chart.setBackgroundPaint(java.awt.Color.white);//设置图片的背景色Font font = new Font("黑体",Font.CENTER_BASELINE,20);//设置图片标题的字体和大小TextTitle _title = new TextTitle(title);_title.setFont(font);chart.setTitle(_title);//把生成的图片放到临时目录ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());//500是图片长度，300是图片高度filename = ServletUtilities.saveChartAsPNG(chart, 500, 300, info, session);ChartUtilities.writeImageMap(pw, filename, info);pw.flush();} catch (Exception e) {System.out.println("Exception - " + e.toString());e.printStackTrace(System.out);filename = "public_error_500x300.png";}return filename;}}

JSP文件

<%@ page contentType="text/html;charset=GBK"%><%@ page import = "java.io.PrintWriter" %><%@ page import="net.sentom.chart.WebChart"%><%WebChart chart = new WebChart();chart.setValue("六月",500);chart.setValue("七月",580);chart.setValue("八月",828);String filename = chart.generatePieChart("www.SenTom.net 网站访问统计表", session, new PrintWriter(out));String graphURL = request.getContextPath() + "/servlet/DisplayChart?filename=" + filename;%>

生成的饼状图如下四 参考资源
http://sourceforge.net/projects/jfreechart
http://www.jfree.org/jfreechart/index.html
http://www.jfree.org/phpBB2/viewforum.php?f=3

原作者：王恩建
来 源：http://www.sentom.net