cewolf统计图的问题

Question

在调一个cewolf做的统计图的东西页面上加上这一句
<cewolf:img chartid="lineChart" renderer="/cewolf" width="300" height="300"/>
访问页面就报错：///////////////////////////////////////////////////
HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: An exception occurred processing JSP page /tools/dbconmonitor/monitorTool.jsp at line 8178:         </cewolf:producer>
79:     </cewolf:data>
80: </cewolf:chart>
81: <cewolf:img chartid="lineChart" renderer="/cewolf" width="300" height="300"/>
82: 
83: </DIV>
84: </div>
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:505)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:416)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:461)
cn.net.withub.authorization.FilterDispatcherWithAuth.doFilter(FilterDispatcherWithAuth.java:221)
org.extremecomponents.table.filter.AbstractExportFilter.doFilter(AbstractExportFilter.java:53)
root cause java.lang.NullPointerException
de.laures.cewolf.taglib.tags.ChartImgTag.doStartTag(ChartImgTag.java:78)
org.apache.jsp.tools.dbconmonitor.monitorTool_jsp._jspx_meth_cewolf_005fimg_005f0(monitorTool_jsp.java:440)
org.apache.jsp.tools.dbconmonitor.monitorTool_jsp._jspService(monitorTool_jsp.java:294)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:461)
cn.net.withub.authorization.FilterDispatcherWithAuth.doFilter(FilterDispatcherWithAuth.java:221)
org.extremecomponents.table.filter.AbstractExportFilter.doFilter(AbstractExportFilter.java:53)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.16 logs.////////////////////////////////////////////////////
去掉这一句就不报错了，但是页面显示不正常，是缺少什么jar包还是怎么回事

Answer 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【yupncai】截止到2008-07-31 09:58:52的历史汇总数据(不包括此帖)：
发帖的总数量:15                       发帖的总分数:340                      每贴平均分数:22                       
回帖的总数量:22                       得分贴总数量:1                        回帖的得分率:4%                       
结贴的总数量:7                        结贴的总分数:120                      
无满意结贴数:1                        无满意结贴分:0                        
未结的帖子数:8                        未结的总分数:220                      
结贴的百分比:46.67 %               结分的百分比:35.29 %                  
无满意结贴率:14.29 %               无满意结分率:0.00  %                  
楼主该结一些帖子了
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