关于JFreeChart的问题

Question

1.保证Jfreechart需要的包在lib目录下
2.在web.xml中加入<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>