jsp生产饼图

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：		 



             <servlet>

        

               <servlet-name>DisplayChart</servlet-name>

        

               <servlet-class>org.jfree.chart.servlet.DisplayChart</servlet-class>

        

             </servlet>

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; 

        

        %>

        <HTML>

        <HEAD>

                  <TITLE>www.sentom.net</TITLE>

        </HEAD>

        <BODY>

        <P ALIGN="CENTER">

                  <img src="<%= graphURL %>" width=500 height=300 border=0 usemap="#<%= filename 

        

        %>">

        </P>

        </BODY>

        </HTML>

就这么简单

 

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;

        

        %>

        <HTML>

        <HEAD>

        <TITLE>www.sentom.net</TITLE>

        </HEAD>

        <BODY>

        <P ALIGN="CENTER">

        <img src="<%= graphURL %>" width=500 height=300 border=0 usemap="#<%= 

        

        filename %>">

        </P>

        </BODY>

        </HTML>
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

 

posted @ 2009-01-05 20:22  瞭望者  阅读(871)  评论(0)    收藏  举报