自己最近學(xué)習(xí)了JfreeChart的使用，覺(jué)得這個(gè)冬冬的功能非常強(qiáng)大，總結(jié)一下。
一、簡(jiǎn)單介紹一下
??? WW 的發(fā)展使得基于因特網(wǎng)的應(yīng)用程序不再局限于靜態(tài)或者簡(jiǎn)單的動(dòng)態(tài)內(nèi)容提供。傳統(tǒng)的一些以軟件包形式發(fā)布應(yīng)用程序例如報(bào)表系統(tǒng)等都在逐漸搬到因特網(wǎng)上。但是這兩者之間有著天壤之別，雖然對(duì)于數(shù)據(jù)獲取、業(yè)務(wù)處理等方面基本類似，但是最大的差別在于用戶界面。為了能在web瀏覽器上顯示要求用戶界面使用 HTML以及圖片的方式來(lái)展現(xiàn)數(shù)據(jù)，而傳統(tǒng)的一些利用操作系統(tǒng)本身的控件來(lái)開(kāi)發(fā)的用戶界面無(wú)法適應(yīng)琳瑯滿目的客戶端，因此在這里也變得無(wú)能為力。回到本文的題目上來(lái)，為了創(chuàng)建一個(gè)可以在web瀏覽器上查看到圖表一般有兩種做法：第一種就是使用applet利用java本身對(duì)圖形的支持來(lái)顯示一個(gè)圖表；第二 種就是直接在web服務(wù)器端生成好圖表圖片文件后發(fā)送給瀏覽器。第一種方式顯然對(duì)于客戶端要求太高，隨著現(xiàn)在主流瀏覽器放棄對(duì)JAVA的支持后，這種方式 只適合一些局域網(wǎng)的應(yīng)用，而對(duì)于因特網(wǎng)的環(huán)境就顯得不太適合。因此我們下面將介紹一個(gè)JAVA的圖表引擎JFreeChart用來(lái)產(chǎn)生基于WEB的圖表。
??? JFreeChart 項(xiàng)目簡(jiǎn)介 JFreeChart是開(kāi)放源代碼站點(diǎn)SourceForge.net上的一個(gè)JAVA項(xiàng)目，它主要用來(lái)各種各樣的圖表，這些圖表包括：餅圖、柱狀圖(普 通柱狀圖以及堆棧柱狀圖)、線圖、區(qū)域圖、分布圖、混合圖、甘特圖以及一些儀表盤(pán)等等。這些不同式樣的圖表基本上可以滿足目前的要求。

二、JFreeChart獲取。
???????? JFreeChart 是JFreeChart公司在開(kāi)源網(wǎng)站SourceForge.net上的一個(gè)項(xiàng)目，該公司的主要產(chǎn)品有如下：
???????? 1.JFreeReport ：報(bào)表解決工具
???????? 2.JFreeChart:Java 圖形解決方案（Application/Applet/Servlet/Jsp）
???????? 3.JCommon ：JFreeReport和JFreeChart的公共類庫(kù)
???????? 4.JFreeDesigner ：JFreeReport的報(bào)表設(shè)計(jì)工具
???? 我們可以從jfree官方網(wǎng)站上獲取最新版本和相關(guān)資料（但是jfree的document需要40美金才能獲取），
???? 獲取地址：http://www.jfree.org/jfreechart/index.html（同時(shí)可以獲得簡(jiǎn)明介紹）
???? 我們以當(dāng)前最新版本：jfreechart-1.0.1.zip為例子進(jìn)行說(shuō)明。

三、JFreeChart配置安裝
???? 1 、解壓jfreechart-1.0.1.zip.zip到指定位置，其中source是jfreechart的源碼，jfreechart-1.0.1-demo.jar ? 是例子程序，可以先運(yùn)行一下看看各種效果，就知道他的nb之處了。
??? 2 、為了配置成功，我們需要關(guān)注的文件有如下三個(gè)：
??? 設(shè)置classpath。加入下面三個(gè)jar包。
??? jfreechart-1.0.1.jar 、jcommon-1.0.0.jar、gnujaxp.jar
??? 加上第三個(gè)jar包有時(shí)web.xml會(huì)報(bào)錯(cuò)，把它去掉就好了。
??????? 至此jfreechart的配置就完成了，下面就可以進(jìn)行jfreechart的開(kāi)發(fā)了。這里值得提出的是jfreechart的類
??????? 結(jié)構(gòu)設(shè)計(jì)前后兼容性不是很好，不同版本的jfreechart中類庫(kù)結(jié)構(gòu)可能不一樣，有時(shí)候可能需要查源碼。如果是中文顯示的時(shí)候可能依據(jù)觀感需要改變?cè)创a的字體。

四、JFreeChart功能介紹
???? JFreeChart 目前是最好的java圖形解決方案，基本能夠解決目前的圖形方面的需求，主要包括如下幾個(gè)方面：
???? pie ? charts ? (2D ? and ? 3D) ：餅圖（平面和立體）
???? bar ? charts ? (regular ? and ? stacked, ? with ? an ? optional ? 3D ? effect) ：柱狀圖
???? line ? and ? area ? charts ：曲線圖
???? scatter ? plots ? and ? bubble ? charts
???? time ? series, ? high/low/open/close ? charts ? and ? candle ? stick ? charts ：時(shí)序圖
???? combination ? charts ：復(fù)合圖
???? Pareto ? charts
???? Gantt ? charts ：甘特圖
???? wind ? plots, ? meter ? charts ? and ? symbol ? charts
???? wafer ? map ? charts
???? ( 態(tài)圖表,餅圖(二維和三維) ? , ? 柱狀圖 ? ( 水平,垂直),線圖,點(diǎn)圖,時(shí)間變化圖,甘特圖, ? 股票行情圖,混和圖, ? 溫度計(jì)圖, ? 刻度圖等常用商用圖表)
???? 圖形可以導(dǎo)出成PNG和JPEG格式，同時(shí)還可以與PDF和EXCEL關(guān)聯(lián)
???? JFreeChart 核心類庫(kù)介紹：
???????????? 研究jfreechart源碼發(fā)現(xiàn)源碼的主要由兩個(gè)大的包組成：org.jfree.chart,org.jfree.data。其中前者主要與圖形
???? 本身有關(guān)，后者與圖形顯示的數(shù)據(jù)有關(guān)。具體研究如果大家有興趣的話可以自己研究 ?? 。
????????? 核心類主要有：
??????????? org.jfree.chart.JFreeChart ：圖表對(duì)象，任何類型的圖表的最終表現(xiàn)形式都是在該對(duì)象進(jìn)行一些屬性的定制。JFreeChart引擎本身提供了一個(gè)工廠類用于創(chuàng)建不同類型的圖表對(duì)象
??????????? org.jfree.data.category.XXXDataSet: 數(shù)據(jù)集對(duì)象，用于提供顯示圖表所用的數(shù)據(jù)。根據(jù)不同類型的圖表對(duì)應(yīng)著很多類型的數(shù)據(jù)集對(duì)象類
??????????? org.jfree.chart.plot.XXXPlot ：圖表區(qū)域?qū)ο螅旧线@個(gè)對(duì)象決定著什么樣式的圖表，創(chuàng)建該對(duì)象的時(shí)候需要Axis、Renderer以及數(shù)據(jù)集對(duì)象的支持
??????????? org.jfree.chart.axis.XXXAxis ：用于處理圖表的兩個(gè)軸：縱軸和橫軸
??????????? org.jfree.chart.render.XXXRender ：負(fù)責(zé)如何顯示一個(gè)圖表對(duì)象
??????????? org.jfree.chart.urls.XXXURLGenerator: 用于生成Web圖表中每個(gè)項(xiàng)目的鼠標(biāo)點(diǎn)擊鏈接
??????????? XXXXXToolTipGenerator: 用于生成圖象的幫助提示，不同類型圖表對(duì)應(yīng)不同類型的工具提示類

??? 個(gè)人感覺(jué)JFreeChart可以滿足大部分圖片創(chuàng)建的需要，美中不足的是：對(duì)字體的設(shè)置做的不夠好，特別是使用中文的時(shí)候字體很不清晰。因?yàn)檫@個(gè)原因建議你自己去修改他的源代碼
最好使用properties文件去設(shè)置字體.還有就是文檔要錢(qián)所以要多花點(diǎn)時(shí)間去看源代碼。或多上社區(qū).

五．開(kāi)始開(kāi)發(fā)
??? 對(duì)JfreeChart有了初步了解并做好準(zhǔn)備工作之后，開(kāi)始作例子程序試驗(yàn)。在這里我只介紹餅圖的做法，而這張圖采用不同的方式進(jìn)行輸出，其他類型的圖片可以參考jfreechart提供的例子，做法都差不多。

1） 直接生成圖片
package com.jfreechart.picture.example;
import java.awt.Color;
import java.awt.Font;
import java.io.FileOutputStream;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtilities;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.labels.StandardPieSectionLabelGenerator;
import org.jfree.chart.plot.PiePlot3D;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.title.TextTitle;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.general.PieDataset;

/**

* 該類用于演示餅圖生成,生成圖片

*/
public class PieChartPicture {

public static void main(String[] args)

??? {
??? ? PieDataset dataset = getDataSet();
??? ? JFreeChart chart = ChartFactory.createPieChart3D(
?? ? ? " 項(xiàng)目進(jìn)度分布",? // chart title
?? ??? ??? dataset,??? ?????????// data
??? ??? ??? true,?????????????? // include legend
??? ??? ? ? true,
??? ??? ??? false
??? ??? ??? );
??? PiePlot3D? plot=(PiePlot3D)chart.getPlot();
??? // 圖片中顯示百分比:默認(rèn)方式
??? //plot.setLabelGenerator(new ??? ????? StandardPieSectionLabelGenerator(StandardPieToolTipGenerator.DEFAULT_TOOLTIP_FORMAT));
// 圖片中顯示百分比:自定義方式，{0} 表示選項(xiàng)， {1} 表示數(shù)值， {2} 表示所占比例 ,小數(shù)點(diǎn)后兩位
??? plot.setLabelGenerator(new StandardPieSectionLabelGenerator("{0}={1}({2})", NumberFormat.getNumberInstance(), new DecimalFormat("0.00%")));

// 圖例顯示百分比:自定義方式， {0} 表示選項(xiàng)， {1} 表示數(shù)值， {2} 表示所占比例??? ??? ???? ??? plot.setLegendLabelGenerator(new StandardPieSectionLabelGenerator("{0}={1}({2})"));

// 設(shè)置背景色為白色

?????? chart.setBackgroundPaint(Color.white);

?????? // 指定圖片的透明度(0.0-1.0)

?????? ?plot.setForegroundAlpha(1.0f);

?????? ?// 指定顯示的餅圖上圓形(false)還橢圓形(true)

?????? ?plot.setCircular(true);

?????? ?// 設(shè)置圖標(biāo)題的字體

?????? Font font = new Font(" 黑體",Font.CENTER_BASELINE,20);

?????? TextTitle title = new TextTitle(" 項(xiàng)目狀態(tài)分布");

?????? title.setFont(font);?

?????? chart.setTitle(title);

?????? FileOutputStream fos_jpg = null;

??? ??? try {

?????????? fos_jpg=new FileOutputStream("D:\\ 項(xiàng)目狀態(tài)分布.jpg");

?????????? ChartUtilities.writeChartAsJPEG(fos_jpg,100,chart,640,480,null);

?????????? fos_jpg.close();

?????? } catch (Exception e) {

?????????? // TODO: handle exception

?????? }

?}

?private static PieDataset getDataSet() {

??? ? ?????? DefaultPieDataset dataset = new DefaultPieDataset();

??? ??????? dataset.setValue(" 市場(chǎng)前期", new Double(10));

??? ??????? dataset.setValue(" 立項(xiàng)", new Double(15));

??? ??????? dataset.setValue(" 計(jì)劃", new Double(10));

??? ??????? dataset.setValue(" 需求與設(shè)計(jì)", new Double(10));

??? ??????? dataset.setValue(" 執(zhí)行控制", new Double(35));

??? ??????? dataset.setValue(" 收尾", new Double(10));

??? ??????? dataset.setValue(" 運(yùn)維",new Double(10));

??? ??????? return dataset;???????

??? ??? }
}

2) 采用servlet和struts的action方式輸出

采用這種方式輸出，不用生成圖片。

A ．servlet輸出

package com.jfreechart.servlet.example;

import java.io.IOException;

import java.awt.Color;

import java.awt.Font;

import java.text.NumberFormat;

import java.text.DecimalFormat;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.http.HttpServlet;

import org.jfree.chart.title.TextTitle;

import org.jfree.chart.ChartFactory;

import org.jfree.chart.ChartUtilities;

import org.jfree.chart.JFreeChart;

import org.jfree.data.general.DefaultPieDataset;

import org.jfree.data.general.PieDataset;

import org.jfree.chart.plot.*;

import org.jfree.chart.labels.StandardPieSectionLabelGenerator;

/**

* 演示通過(guò)servlet直接輸出餅圖

*/

public class PieByServlet extends HttpServlet{

public void service(ServletRequest req, ServletResponse res)

??? throws ServletException, IOException

??? {

?????? res.setContentType("image/jpeg");

?????? PieDataset dataset = getDataSet();

?????? JFreeChart chart = ChartFactory.createPieChart3D(

??? ??????????? " 水果餅圖",? // chart title

??? ???????? ???dataset,???????????? // data

??? ??????????? true,?????????????? // include legend

??? ??????????? true,

??? ??????????? false

??? ??????? );

?????? PiePlot3D? plot=(PiePlot3D)chart.getPlot();?

?????? // 圖片中顯示百分比:默認(rèn)方式

?????? //plot.setLabelGenerator(new StandardPieSectionLabelGenerator(StandardPieToolTipGenerator.DEFAULT_TOOLTIP_FORMAT));

// 圖片中顯示百分比:自定義方式，{0} 表示選項(xiàng)， {1} 表示數(shù)值， {2} 表示所占比例 ,小數(shù)點(diǎn)后兩位

???? plot.setLabelGenerator(new StandardPieSectionLabelGenerator("{0}={1}({2})", NumberFormat.getNumberInstance(), new DecimalFormat("0.00%")));

// 圖例顯示百分比:自定義方式， {0} 表示選項(xiàng)， {1} 表示數(shù)值， {2} 表示所占比例

????? plot.setLegendLabelGenerator(new StandardPieSectionLabelGenerator("{0}={1}({2})"));

?// 設(shè)置背景色為白色

?????? chart.setBackgroundPaint(Color.white);

?????? // 指定圖片的透明度(0.0-1.0)

?????? ?plot.setForegroundAlpha(1.0f);

?????? ?// 指定顯示的餅圖上圓形(false)還橢圓形(true)

?????? ?plot.setCircular(true);

?????? ?// 設(shè)置圖標(biāo)題的字體

?????? Font font = new Font(" 黑體",Font.CENTER_BASELINE,20);

?????? TextTitle title = new TextTitle(" 項(xiàng)目狀態(tài)分布");

?????? title.setFont(font);

??? ??? chart.setTitle(title);

?????? // 輸出圖片

?????? ChartUtilities.writeChartAsJPEG(res.getOutputStream(),100,chart,800,600,null);

??? }

??? /**

??? * 獲取一個(gè)演示用的簡(jiǎn)單數(shù)據(jù)集對(duì)象

??? * @return

??? */

??? private static DefaultPieDataset getDataSet() {

?????? DefaultPieDataset dataset = new DefaultPieDataset();

??? ??????? dataset.setValue(" 市場(chǎng)前期", new Double(10));

??? ??????? dataset.setValue(" 立項(xiàng)", new Double(15));

??? ??????? dataset.setValue(" 計(jì)劃", new Double(10));

??? ??????? dataset.setValue(" 需求與設(shè)計(jì)", new Double(10));

??? ??????? dataset.setValue(" 執(zhí)行控制", new Double(35));

??? ??????? dataset.setValue(" 收尾", new Double(10));

??? ??????? dataset.setValue(" 運(yùn)維",new Double(10));

??? ??????? return dataset;???????
??? }
}

B ．struts的action方式輸出

只將這條語(yǔ)句加上try catch即可，并返回null。

try{?????? ChartUtilities.writeChartAsJPEG(response.getOutputStream(),100,chart,800,600,null);

??? } catch (Exception e) {

????????????? // TODO: handle exception

??? }
return null;

其實(shí)采用這兩種方式與生成圖片的方式改動(dòng)并不大

加上語(yǔ)句response.setContentType("image/jpeg");

ChartUtilities.writeChartAsJPEG(new FileOutputStream("D:\\ 項(xiàng)目狀態(tài)分布.jpg");,100,chart,640,480,null);

文件流改成response的輸出流就可以了

ChartUtilities.writeChartAsJPEG(response.getOutputStream(),100,chart,800,600,null);

?

?3）jsp＋servlet＋javabean方式

1. Create ChartViewer servlet (ChartViewer.java)

Code:

/**

?* Need to produce some chart prior to this action call in a Java bean

?* Need a session attribute named "chartImage";

?*/

package myapp.webwork.servlets;

import java.io.*;

import java.awt.image.*;

import javax.servlet.*;

import javax.servlet.http.*;

import com.keypoint.PngEncoder;

public class ChartViewer extends HttpServlet {

?public void init() throws ServletException {

? }

?
//Process the HTTP Get request

? public void doGet(HttpServletRequest request, HttpServletResponse response)

???????? throws ServletException, IOException {

? // get the chart from session

?? HttpSession session = request.getSession();

?? BufferedImage chartImage = (BufferedImage) session.getAttribute("chartImage");

// set the content type so the browser can see this as a picture

?? response.setContentType("image/png");

// send the picture

?? PngEncoder encoder = new PngEncoder(chartImage, false, 0, 9);

?? response.getOutputStream().write(encoder.pngEncode());

}

//Process the HTTP Post request

? public void doPost(HttpServletRequest request, HttpServletResponse response)

???????? throws ServletException, IOException {

??? doGet(request, response);

? }

//Process the HTTP Put request

? public void doPut(HttpServletRequest request, HttpServletResponse response)

???????? throws ServletException, IOException {

? }

//Clean up resources

? public void destroy() {

? }

}

?
2. Compile and store the servlet under WEB-INF/classes

<appname>WEB-INF/classes/myapp/webwork/servlets

3. Create a servlet map in web.xml

Code:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE web-app

??? PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"

??? "http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">

<web-app>

? <servlet>

??? <servlet-name>ChartViewer</servlet-name>

??? <servlet-class>myapp.webwork.servlets.ChartViewer</servlet-class>

? </servlet>

? <servlet-mapping>

??? <servlet-name>ChartViewer</servlet-name>

??? <url-pattern>/servlet/ChartViewer</url-pattern>

? </servlet-mapping>

</web-app>

4. Create a chart in a java bean (Pie3DDemo.java)

Code:

/**

?*

?* JFreeChart version 0.9.20

?* Called by Pie3DDemo.jsp

?*

?*/

package myapp.webwork.beans;

import java.io.*;

import java.awt.*;

import java.util.*;

import java.awt.image.*;

import org.jfree.data.*;

import org.jfree.chart.*;

import org.jfree.chart.plot.*;

import org.jfree.chart.urls.*;

import org.jfree.chart.entity.*;

import javax.servlet.http.*;

public class Pie3DDemo {

?public Pie3DDemo() {

? }

private DefaultPieDataset getDataset() {

??? // categories...

??? String[] section = new String[] {

????? "Jan","Feb","Mar","Apr","May","Jun",

????? "Jul","Aug","Sep","Oct","Nov","Dec"

?? };

?// data...

??? double[] data = new double[section.length];

??? for (int i = 0; i < data.length; i++) {

??????? data[i] = 10 + (Math.random() * 10);

??? }

// create the dataset...

??? DefaultPieDataset dataset = new DefaultPieDataset();

??? for (int i = 0; i < data.length; i++) {

??????? dataset.setValue(section[i], data[i]);

??? }

??? return dataset;

? }

?public String getChartViewer(HttpServletRequest request, HttpServletResponse response) {

??? DefaultPieDataset dataset = getDataset();

??? // create the chart...

??? JFreeChart chart = ChartFactory.createPie3DChart(

????????? "Pie3D Chart Demo",? // chart title

????????? dataset,???????????? // data

????????? true,??????????????? // include legend

????????? true,

????????? false

??? );

? // set the background color for the chart...

??? chart.setBackgroundPaint(Color.cyan);

??? PiePlot plot = (PiePlot) chart.getPlot();

??? plot.setNoDataMessage("No data available");

?// set drilldown capability...

??? plot.setURLGenerator(new StandardPieURLGenerator("Bar3DDemo.jsp","section"));

??? plot.setLabelGenerator(null);

? // OPTIONAL CUSTOMISATION COMPLETED.

? ChartRenderingInfo info = null;

??? HttpSession session = request.getSession();

??? try {

? //Create RenderingInfo object

????? response.setContentType("text/html");

????? info = new ChartRenderingInfo(new StandardEntityCollection());

????? BufferedImage chartImage = chart.createBufferedImage(640, 400, info);

? // putting chart as BufferedImage in session,

????? // thus making it available for the image reading action Action.

????? session.setAttribute("chartImage", chartImage);

???? PrintWriter writer = new PrintWriter(response.getWriter());

????? ChartUtilities.writeImageMap(writer, "imageMap", info);

????? writer.flush();

? }

??? catch (Exception e) {

?????? // handel your exception here

??? }

?String pathInfo = "http://";

??? pathInfo += request.getServerName();

??? int port = request.getServerPort();

??? pathInfo += ":"+String.valueOf(port);

?? ?pathInfo += request.getContextPath();

??? String chartViewer = pathInfo + "/servlet/ChartViewer";

??? return chartViewer;

? }

}

?

5. Compile and store the bean under WEB-INF/classes

<appname>WEB-INF/classes/myapp/webwork/beans

6. Create Pie3DDemo.jsp code

Code:

<html>

<head>

<title>Pie Chart Demo</title>

</head>

<jsp:useBeanid="myChart"scope="session"class="myapp.webwork.beans.Pie3DDemo" />

<body>

<h2>Pie Chart Demo</h2>

<%String chartViewer = myChart.getChartViewer(request, response);%>

<img src="<%=chartViewer%>" border=0 usemap="#imageMap">

</body>

</html>

?4）采用工具類，DisplayChart輸出
我用了上面的幾個(gè)方法輸出圖片，發(fā)現(xiàn)頁(yè)面里只能輸出一個(gè)圖片，
不過(guò)下面的方法可以輸出多個(gè)圖片

1 ．添加工具類ChartUtil

public class ChartUtil {

//? 產(chǎn)生時(shí)間序列圖，返回圖片名稱

??? ?// 產(chǎn)生餅圖，返回圖片名稱

??? ? public? static String generatePieChart(DefaultPieDataset dataset,String title,int width,int height,HttpSession session, PrintWriter pw) {

?????????? String filename = null;

?????????? try {

????????????? if (session != null)

????????????? {

????????????????? ChartDeleter deleter = (ChartDeleter)session.getAttribute("JFreeChart_Deleter");

????????????????? session.removeAttribute("JFreeChart_Deleter");

????????????????? session.setAttribute("JFreeChart_Deleter", deleter);

????????????? }

????????????? ?JFreeChart chart = ChartFactory.createPieChart3D(

????????????? ????????? title,? // chart title

????????????? ????????? dataset,???????????? // data

????????????? ????????? true,??????????????? // include legend

????????????? ????????? true,

????????????? ??? ??????false

????????????? ??? );

? ? //? Write the chart image to the temporary directory

????????????? ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());

????????????? //If the last parameter is null, the chart is a "one time"-chart and will be deleted after the first serving.

????????????? //If the last parameter is a session object, the chart remains until session time out.

????????????? filename = ServletUtilities.saveChartAsPNG(chart, width, height, info, session);

? ? //? Write the image map to the PrintWriter

????????????? ChartUtilities.writeImageMap(pw, filename, info,true);

????????????? pw.flush();

?????????? } catch (Exception e) {

????????????? System.out.println("Exception - " + e.toString());

????????????? e.printStackTrace(System.out);

????????????? filename = "picture_error.png";

?????????? }

?????????? return filename;

?????? }

}

2 ．在頁(yè)面里

統(tǒng)計(jì)好dataset，傳到頁(yè)面。

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<%@ page import="com.jfreechart.util.ChartUtil"%>

<%@ page import="org.jfree.data.general.DefaultPieDataset"%>

<%@ page import = "java.io.PrintWriter" %>

<%

??? DefaultPieDataset piedataset=(DefaultPieDataset)request.getAttribute("piedataset");

%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

? <head>

??? <base href="<%=basePath%>">

? ? <title>chartDemo.jsp</title>

??? <meta http-equiv="pragma" content="no-cache">

??? <meta http-equiv="cache-control" content="no-cache">

??? <meta http-equiv="expires" content="0">

??? <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">

??? <meta http-equiv="description" content="This is my page">

?? <!--

??? <link rel="stylesheet" type="text/css" href="styles.css">

??? -->

? </head>

<body>

??? <%

??? // 用ChartUtil工具類輸出

??? String p = ChartUtil.generatePieChart(piedataset," 項(xiàng)目收支線圖",500,300,null, new PrintWriter(out));

??? String p1 = request.getContextPath() + "/servlet/DisplayChart?filename=" + p;

??? %>

??? <TABLE>

?????? <tr>

??? <td><img src="<%= p1 %>" width=500 height=300 border=0 usemap="#<%= p %>"></td>

??? </tr>

??? </TABLE>

? </body>

</html>

3 ．在web.xml中添加

? <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>/servlet/DisplayChart</url-pattern>
???????????????? </servlet-mapping>

5） ApplicationFrame 方式

package com.taiji.jfreechart.frame.example;

import java.awt.Font;

import javax.swing.JPanel;

import org.jfree.chart.ChartFactory;

import org.jfree.chart.ChartPanel;

import org.jfree.chart.JFreeChart;

import org.jfree.chart.plot.PiePlot;

import org.jfree.data.general.DefaultPieDataset;

import org.jfree.data.general.PieDataset;

import org.jfree.ui.ApplicationFrame;

import org.jfree.ui.RefineryUtilities;

/**

?* A simple demonstration application showing how to create a pie chart using

?* data from a {@link DefaultPieDataset}.

?*/

public class PieChartDemo1 extends ApplicationFrame {

? /**

???? * Default constructor.

???? *

???? * @param title? the frame title.

???? */

??? public PieChartDemo1(String title) {

??????? super(title);

??????? setContentPane(createDemoPanel());

??? }

? /**

???? * Creates a sample dataset.

???? *

???? * @return A sample dataset.

???? */

??? private static PieDataset createDataset() {

??????? DefaultPieDataset dataset = new DefaultPieDataset();

??????? dataset.setValue("One", new Double(43.2));

??????? dataset.setValue("Two", new Double(10.0));

??????? dataset.setValue("Three", new Double(27.5));

??????? dataset.setValue("Four", new Double(17.5));

??????? dataset.setValue("Five", new Double(11.0));

??????? dataset.setValue("Six", new Double(19.4));

??????? return dataset;???????

??? }

??/**

???? * Creates a chart.

???? *

???? * @param dataset? the dataset.

???? *

???? * @return A chart.

???? */

??? private static JFreeChart createChart(PieDataset dataset) {

??? JFreeChart chart = ChartFactory.createPieChart(

??????????? "Pie Chart Demo 1",? // chart title

??????????? dataset,????????? ???// data

??????????? true,?????????????? // include legend

??????????? true,

??????????? false

??????? );

? ? PiePlot plot = (PiePlot) chart.getPlot();

??????? plot.setSectionOutlinesVisible(false);

??????? plot.setLabelFont(new Font("SansSerif", Font.PLAIN, 12));

??????? plot.setNoDataMessage("No data available");

??????? plot.setCircular(false);

??????? plot.setLabelGap(0.02);

??????? return chart;

???????

??? }

?/**

???? * Creates a panel for the demo (used by SuperDemo.java).

???? *

?? ??* @return A panel.

???? */

??? public static JPanel createDemoPanel() {

??????? JFreeChart chart = createChart(createDataset());

??????? return new ChartPanel(chart);

??? }

? /**

???? * Starting point for the demonstration application.

???? *

??? ?* @param args? ignored.

???? */

??? public static void main(String[] args) {

? ??? ? PieChartDemo1 demo = new PieChartDemo1("Pie Chart Demo 1");

??????? demo.pack();

??????? RefineryUtilities.centerFrameOnScreen(demo);

??????? demo.setVisible(true);

??? }

}

六. 可參考資料與網(wǎng)址

官方網(wǎng)站

http://www.jfree.org/jfreechart/index.html

?? 官方論壇

http://www.jfree.org/phpBB2/index.php

API 文檔

http://www.jfree.org/jfreechart/api/gjdoc/index.html

???中文API

???? http://blog.sina.com.cn/u/405da78d010000ap

好了，嘮叨了這么多，寫(xiě)東西真tmd類。