How can I map the url of my web item to a servlet

[JK]

I am trying to create a jira plug in so for that i created a web item in required place and now iam not able to map the url while clicking the web item to the servlet, I tried changing the web.XML of the plug in but it's not working do i want to make any change in web. XML of Tomcat 

[Graham Twine]

Hello @JK 

There is no need to change the tomcat web.xml file for a Jira plugin.

This is configured in the plugin.xml

Your web item xml may look like this. All it contains is a link in the UI, admin panel etc.

The link element has a url in there that will be invoked when it is clicked

<web-item key="${atlassian.plugin.key}-EventListenerMenuItem"
          name="Admin Menu : Event Listener Configuration Menu Link"
          section="admin_plugins_menu/${atlassian.plugin.key}-AdminMenu"
          weight="131"
         application="jira">
   <description>Event Listener Configuration</description>
   <label key="el.admin.label" />
   <link linkId="${atlassian.plugin.key}-EventListenerAdminLink">
      /plugins/servlet/eventlistener/admin
   </link>
</web-item

An additional element to listen for the request.

<!-- Configuration Servlet -->

<servlet key="${atlassian.plugin.key}-EventListenerAdminConfig"
         name="Event Listener : Configuration"
        class="za.co.liquidesign.jira.admin.events.EventListenerAdmin">
   <url-pattern>/eventlistener/admin</url-pattern>
</servlet>

The class referenced in the servlet element

public class EventListenerAdmin extends HttpServlet {
 @ @Override
   public void doGet(HttpServletRequest request, HttpServletResponse response)
throws IOException, ServletException {

   }
}