求助jfreechart

Question

javax.servlet.ServletException: org.jfree.data.time.TimeSeries.<init>(Ljava/lang/Comparable;Ljava/lang/Class;)V
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:825)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:758)
org.apache.jsp.glpt.EC.Greatb_jsp._jspService(Greatb_jsp.java:89)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:321)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
请问这个错怎么解决啊

Answer 1

看看web-xml文件中配置相应JFEE的信息没

Answer 2

<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>/servlets/DisplayChart</url-pattern>
  </servlet-mapping>

Answer 3

检查下是不是引用了不同版本的jar包