JFreeChart初学者入门实例详细解析(转载）

来源：互联网发布：软件开发薪资待遇编辑：程序博客网时间：2024/06/04 22:06

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，下面就是一张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-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>

<ccid_file values="<%=" graphURL % />"

width=500 height=300 border=0

usemap="#<%= filename

%>">

</P>

</BODY>

</HTML>

就这么简单，生成的饼状图如下

三、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">
    <ccid_file values="<%=" graphURL % />
    " width=500 height=300
    border=0 usemap="#<%=

filename %>">
</P>
</BODY>
</HTML>

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