web.xml文件錯誤

Question

<?xml version="1.0" encoding="ISO-8859-1"?><!DOCTYPE web-app
    PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
    "http://java.sun.com/dtd/web-app_2_3.dtd"><web-app>
  <display-name>WebLogic Servlet</display-name>
  
  <servlet>
    <servlet-name>HelloWorldServlet</servlet-name>
    <servlet-class>servlet.HelloWorldServlet</servlet-class>
  </servlet>
  
    <servlet>
    <servlet-name>message</servlet-name>
    <servlet-class>servlet.message</servlet-class>
  </servlet>
  
    <servlet>
    <servlet-name>forum</servlet-name>
    <servlet-class>servlet.forum</servlet-class>
  </servlet>
    
  <servlet-mapping>
    <servlet-name>HelloWorldServlet</servlet-name>
    <url-pattern>/servlet/hello/*</url-pattern>
  </servlet-mapping>
  
  <servlet-mapping>
    <servlet-name>forum</servlet-name>
    <url-pattern>/servlet/forum/*</url-pattern>
  </servlet-mapping>
  
  <servlet-mapping>
    <servlet-name>message</servlet-name>
    <url-pattern>/servlet/message/*</url-pattern>
  </servlet-mapping>
</web-app>