jfreechart不能显示图表

当运行网页时，显示不了图表，请问是什么问题？是不是XML的配置有问题？
<HTML> 
<HEAD> 
<META http-equiv=Content-Type content="text/html; charset=GBK"> 
<TITLE>[email protected]</TITLE> 
</HEAD> 
<BODY> 
<map id="map0" name="map0">
<area shape="poly" coords="247,52,250,52,250,138,250,138" href="barview.jsp%3Fcategory%3D%25E5%258D%259A%25E5%25A3%25AB%26amp%3BpieIndex%3D0" alt=""/>
<area shape="poly" coords="131,122,137,108,146,95,157,83,171,72,188,64,206,58,226,53,247,52,250,138,250,138" href="barview.jsp%3Fcategory%3D%25E7%25A1%2595%25E5%25A3%25AB%26amp%3BpieIndex%3D0" alt=""/>
<area shape="poly" coords="336,198,321,208,305,215,287,220,269,223,250,224,231,223,212,220,194,215,178,207,163,198,151,188,141,176,134,163,130,150,129,136,131,122,250,138,250,138" href="barview.jsp%3Fcategory%3D%25E6%259C%25AC%25E7%25A7%2591%26amp%3BpieIndex%3D0" alt=""/>
<area shape="poly" coords="316,66,336,78,352,93,363,110,369,129,369,148,363,166,352,183,336,198,250,138,250,138" href="barview.jsp%3Fcategory%3D%25E5%25A4%25A7%25E4%25B8%2593%26amp%3BpieIndex%3D0" alt=""/>
<area shape="poly" coords="263,52,291,57,316,66,250,138,250,138" href="barview.jsp%3Fcategory%3D%25E9%25AB%2598%25E4%25B8%25AD%26amp%3BpieIndex%3D0" alt=""/>
<area shape="poly" coords="250,52,263,52,250,138,250,138" href="barview.jsp%3Fcategory%3D%25E9%25AB%2598%25E4%25B8%25AD%25E4%25BB%25A5%25E4%25B8%258B%26amp%3BpieIndex%3D0" alt=""/>
</map>
<P ALIGN="CENTER"> 
<img src="/WebRoot/servlet/DisplayChart?filename=jfreechart-6384.png" width=500 height=300 border=0 usemap="#map0"> 
</P> 
</BODY> 
</HTML>

解决方案 »

  1.   

    此回复为自动发出,仅用于显示而已，并无任何其他特殊作用
    楼主【dazui521】截止到2008-07-23 14:22:19的历史汇总数据(不包括此帖)：
    发帖的总数量:18                       发帖的总分数:320                      每贴平均分数:17                       
    回帖的总数量:10                       得分贴总数量:0                        回帖的得分率:0%                       
    结贴的总数量:18                       结贴的总分数:320                      
    无满意结贴数:5                        无满意结贴分:150                      
    未结的帖子数:0                        未结的总分数:0                        
    结贴的百分比:100.00%               结分的百分比:100.00%                  
    无满意结贴率:27.78 %               无满意结分率:46.88 %                  
    敬礼!
      

  2.   

    何必搞的那么麻烦阿 不用标签直接在服务端生成图表的url 然后把这个路径传到页面 直接<img src="${路径}"> 这样显示就得了 何必做那么麻烦?如果需要文档 留下email 我可以给你发!
      

  3.   

    附源码：
    <%@ page contentType="text/html;charset=GBK"%> 
    <%@ page import="org.jfree.data.general.DefaultPieDataset"%> 
    <%@ page import="org.jfree.chart.*"%> 
    <%@ page import="org.jfree.chart.plot.*"%> 
    <%@ page import="org.jfree.chart.servlet.ServletUtilities"%>
    <%@ page import="org.jfree.chart.urls.StandardPieURLGenerator"%> 
    <%@ page import="org.jfree.chart.entity.StandardEntityCollection"%> 
    <%@ page import="java.io.*"%> 
    <HTML> 
    <HEAD> 
    <META http-equiv=Content-Type content="text/html; charset=GBK"> 
    <TITLE>jfreechart_test</TITLE> 
    </HEAD> 
    <BODY> 
    <% DefaultPieDataset data = new DefaultPieDataset(); 
    data.setValue("高中以下",370); 
    data.setValue("高中",1530); 
    data.setValue("大专",5700); 
    data.setValue("本科",8280); 
    data.setValue("硕士",4420); 
    data.setValue("博士",80); 
    PiePlot3D plot = new PiePlot3D(data);//3D饼图 
    plot.setURLGenerator(new StandardPieURLGenerator("barview.jsp"));//设定链接 
    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("程序员学历情况调查表");//可选，设置图片标题 
    StandardEntityCollection sec = new StandardEntityCollection(); 
    ChartRenderingInfo info = new ChartRenderingInfo(sec); 
    PrintWriter w = new PrintWriter(out);//输出MAP信息 
    //500是图片长度，300是图片高度 
    String filename = ServletUtilities.saveChartAsPNG(chart, 500, 300, info, session); 
    ChartUtilities.writeImageMap(w, "map0", info, false); 
    String graphURL = request.getContextPath() + "/servlet/DisplayChart?filename=" + filename; 
    %>
    <P ALIGN="CENTER"> 
    <img src="<%= graphURL %>" width=500 height=300 border=0 usemap="#map0"> 
    </P> 
    </BODY> 
    </HTML>
      

  4.   

    <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>
    这个能解释一下吗？我写到XML里就不能显示网页了，显示的是404错误。
      

  5.   

    这个是显示图表的一个servlet的配置,只要你导入了DisplayChart 包,不会有问题的,404只是找不到页面而已
      

  6.   

    兄弟？你的热点链接能使用不？
    我看出来，你的热点链接不可用。我也在头痛这个问题。
    就是下面这种错误的href格式
    href="barview.jsp%3Fcategory%3D%25E9%25AB%2598%25E4%25B8%25AD%26amp%3BpieIndex%3D0"
    怎么解决？？？？