sample2.jsp

JFreeChart开发全攻略,JFreeChart开发全攻略

<%@ page contentType="text/html;charset=GBK"%>
<%@ page import="org.jfree.chart.*,
                 org.jfree.chart.plot.PiePlot,
                 org.jfree.data.general.DefaultPieDataset,
                 org.jfree.chart.servlet.ServletUtilities,
                 java.awt.*,
                 org.jfree.chart.labels.StandardPieSectionLabelGenerator,
                 java.text.NumberFormat"%>
<%
//设置数据集
DefaultPieDataset dataset = new DefaultPieDataset();
dataset.setValue("初中高级程序员", 0.55);
dataset.setValue("项目经理", 0.1);
dataset.setValue("系统分析师", 0.1);
dataset.setValue("软件架构师", 0.1);
dataset.setValue("其他", 0.2);

JFreeChart chart = ChartFactory.createPieChart("IT行业职业分布图", dataset, true, false, false);
PiePlot pieplot = (PiePlot) chart.getPlot();
pieplot.setNoDataMessage("无数据显示");
//把Lable 为"其他" 的那一块”挖“出来50% 
pieplot.setExplodePercent("其他", 0.5D);
//显示各项所占的百分比
pieplot.setCircular(true);
pieplot.setLabelGenerator(new StandardPieSectionLabelGenerator("{0} = {2}", NumberFormat.getNumberInstance(), NumberFormat.getPercentInstance()));
//设置各项的标签的背景颜色，默认为黄色
pieplot.setLabelBackgroundPaint(new Color(220, 220, 220));

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 %>">