meter1.jsp

JFreeChart开发全攻略,JFreeChart开发全攻略

<%@ page contentType="text/html;charset=UTF-8"%>
<%@ page import="org.jfree.chart.JFreeChart,
                 org.jfree.chart.servlet.ServletUtilities,
                 java.awt.*,
                 org.jfree.data.general.DefaultValueDataset,
                 org.jfree.chart.plot.MeterPlot,
                 org.jfree.chart.plot.MeterInterval,
                 org.jfree.data.Range"%>
                 
<%
//设置数据集，20为指针初始指向的位置
DefaultValueDataset dataset = new DefaultValueDataset(20);

//根据数据集设置米尺图形对象，并设置其属性
MeterPlot meterplot = new MeterPlot(dataset);
meterplot.addInterval(new MeterInterval("High", new Range(80D, 100D)));
meterplot.setDialOutlinePaint(Color.white);

//创建米尺图的JFreeChart对象
JFreeChart jfreechart = new JFreeChart(
					"米尺图形",
					JFreeChart.DEFAULT_TITLE_FONT,
					meterplot,
					false);

String filename = ServletUtilities.saveChartAsPNG(jfreechart, 400, 400, null, session);
String graphURL = request.getContextPath() + "/DisplayChart?filename=" + filename;
%>
<img src="<%= graphURL %>" width="400" height="400" border="0" usemap="#<%= filename %>">