jfreechart如何生成热区，usemap_jfreechart usemap-优快云博客

本文介绍了一个使用JSP结合JFreeChart库生成3D柱状图的方法。通过预定义的数据集展示了一组水果销售数据，并设置了图表样式、颜色、透明度等属性。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

jsp页面代码如下：

<%@ page contentType="text/html;charset=GBK"%>
<%@ page import="java.awt.Color,
                org.jfree.chart.ChartFactory,
                org.jfree.chart.JFreeChart,
                org.jfree.chart.plot.PlotOrientation,
                org.jfree.chart.servlet.ServletUtilities,
                org.jfree.data.category.CategoryDataset,
                org.jfree.data.general.*,
                org.jfree.chart.plot.CategoryPlot,
                org.jfree.chart.axis.CategoryAxis,
                org.jfree.chart.axis.ValueAxis,
                org.jfree.chart.renderer.category.BarRenderer3D,
                org.jfree.chart.urls.StandardCategoryURLGenerator,
                org.jfree.chart.*,
                org.jfree.chart.entity.*,
                org.jfree.chart.labels.*"%>
<jsp:directive.page import="java.text.DecimalFormat"/>
<jsp:directive.page import="org.jfree.util.SortOrder"/>
<jsp:directive.page import="org.jfree.chart.plot.XYPlot"/>
<jsp:directive.page import="org.jfree.util.TableOrder"/>
<html>
<head>
         <title>My JSP 'test4.jsp' starting page</title>
</head>

<body>

<%
java.io.PrintWriter pw=new java.io.PrintWriter(out);
double[][] data = new double[][] {{672,234}, {325,555}, {332}, {440}, {550}, {330}};
String[] rowKeys = {"苹果", "梨子", "葡萄", "桔子", "西瓜", "香蕉"};
String[] columnKeys = {"11","22"};
CategoryDataset dataset = DatasetUtilities.createCategoryDataset(
        rowKeys,
        columnKeys,
        data);
request.setCharacterEncoding("gbk");
response.setContentType("text/html;charset=gbk");
JFreeChart chart = ChartFactory.createBarChart3D("水果销量图统计",
                  "水果",
                  "销量",
                  dataset,
                  PlotOrientation.VERTICAL,
                  true,
                  true,
                  true);

chart.setBackgroundPaint(Color.WHITE);
CategoryPlot plot = chart.getCategoryPlot();
//XYPlot xyPlot=chart.getXYPlot();
CategoryAxis domainAxis = plot.getDomainAxis();
plot.setDomainAxis(domainAxis);

ValueAxis rangeAxis = plot.getRangeAxis();
//设置最高的一个 Item 与图片顶端的距离
rangeAxis.setUpperMargin(0.15);
//设置最低的一个 Item 与图片底端的距离
rangeAxis.setLowerMargin(0.15);

plot.setRangeAxis(rangeAxis);

BarRenderer3D renderer = new BarRenderer3D();
renderer.setBaseOutlinePaint(Color.BLACK);
//设置 Wall 的颜色
renderer.setWallPaint(Color.gray);
//设置每种水果代表的柱的颜色
renderer.setSeriesPaint(0, new Color(0, 0, 255));
renderer.setSeriesPaint(1, new Color(200, 200, 255));
renderer.setSeriesPaint(2, Color.GREEN);
renderer.setSeriesPaint(3, Color.MAGENTA);
renderer.setSeriesPaint(4, Color.GRAY);
renderer.setSeriesPaint(5, Color.CYAN);

//设置平行柱的之间距离
renderer.setItemMargin(0.3);

//显示每个柱的数值
renderer.setBaseItemLabelGenerator(new StandardCategoryItemLabelGenerator());
renderer.setBaseItemLabelsVisible(true);

renderer.setBaseItemLabelsVisible(true);
renderer.setBaseItemURLGenerator(new StandardCategoryURLGenerator(
"detail.jsp", "fruit", "column"));
renderer.setBaseToolTipGenerator(new StandardCategoryToolTipGenerator(

" [ {0}，{1} ] = {2} ", new DecimalFormat("￥#,###.00")));

plot.setRenderer(renderer);

//设置柱的透明度
plot.setForegroundAlpha(0.5f);
//设置地区、销量的显示位置
//plot.setRangeAxisLocation(AxisLocation.BOTTOM_OR_RIGHT);
ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());

String filename = ServletUtilities.saveChartAsPNG(chart, 800, 600, info, session);
String graphURL = request.getContextPath() + "/servlet/DisplayChart?filename=" + filename;

ChartUtilities.writeImageMap(pw, filename, info, false);
pw.flush();
%>

<table width="100%">
    <tr>
        <td align="center">
            <img src=" <%= graphURL %>" width=800 height=600 border=0 usemap="#<%= filename %>" alt="">
        </td>
    </tr>
</table>

</body>
</html>

web.xml代码如下（测试了，能用）

<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>