websphere portal 5.0中使用jfreechart图片为叉

[haozhenmail]

急切盼望大家能帮助我，我是在websphere portal 5.0中使用jfreechart，在tomcat中显示正常，而在websphere portal 5.0中显示的却为叉，我在服务器的临时文件夹里也能够找到生成的图片，但页面就是没显示，谢谢！

<%@page language="java" contentType="text/html; charset=GB18030"
pageEncoding="GB18030" session="false"%>
<%@taglib uri="/WEB-INF/tld/portlet.tld" prefix="portletAPI"%>
<%@page import="org.jfree.data.time.TimeSeries"%>
<%@page import="org.jfree.data.time.TimeSeriesCollection"%>
<%@page import="org.jfree.chart.JFreeChart"%>
<%@page import="org.jfree.chart.ChartFactory"%>
<%@page import="java.awt.Font"%>
<%@page import="org.jfree.chart.title.TextTitle"%>
<%@page import="org.jfree.data.time.Month"%>
<%@page import="org.jfree.chart.servlet.ServletUtilities"%>

<portletAPI:init />
<%
//访问量统计时间线
TimeSeries timeSeries = new TimeSeries("我的blog访问量统计", Month.class);
//时间曲线数据集合
TimeSeriesCollection lineDataset = new TimeSeriesCollection();
//构造数据集合
timeSeries.add(new Month(1,2007),11200);
timeSeries.add(new Month(2,2007),9000);
timeSeries.add(new Month(3,2007),6200);
timeSeries.add(new Month(4,2007),8200);
timeSeries.add(new Month(5,2007),8200);
timeSeries.add(new Month(6,2007),12200);
timeSeries.add(new Month(7,2007),13200);
timeSeries.add(new Month(8,2007),8300);
timeSeries.add(new Month(9,2007),12400);
timeSeries.add(new Month(10,2007),12500);
timeSeries.add(new Month(11,2007),13600);
timeSeries.add(new Month(12,2007),12500);
lineDataset.addSeries(timeSeries);
JFreeChart chart = ChartFactory.createTimeSeriesChart("访问量统计时间线",
"月份", "访问量", lineDataset, true, true, true);
chart.getTitle().setFont(new Font("黑体", Font.BOLD, 12));
chart.getLegend().setItemFont(new Font("黑体", Font.BOLD, 12));
//设置子标题
TextTitle subtitle = new TextTitle("2007年度", new Font("黑体",
Font.BOLD, 12));
chart.addSubtitle(subtitle);
//设置主标题
chart.setTitle(new TextTitle("blog访问量统计", new Font("隶书",
Font.ITALIC, 15)));
chart.setAntiAlias(true);
String filename = ServletUtilities.saveChartAsPNG(chart, 500, 300,
null,request.getSession());
String graphURL = request.getContextPath()
+ "/servlet/DisplayChart?filename=" + filename;


%>


<img src="<%=graphURL%>" width=500 height=300 border=0
usemap="#<%= filename %>">