我用tomcat服务器: 

 <?xml version="1.0" encoding="ISO-8859-1"?>
<web-app version="2.4" 
    xmlns="http://java.sun.com/xml/ns/j2ee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
  <display-name>j2ee test</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
 
  <servlet>
      <servlet-name>HeaderServlet</servlet-name>
      <servlet-class>HeaderServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>Test</servlet-name>
      <servlet-class>test.Test</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>requestcounterservlet</servlet-name>
      <servlet-class>jwadbook.RequestCounterServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>FormParameterServlet</servlet-name>
      <servlet-class>jwadbook.FormParameterServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>FormDemo</servlet-name>
      <servlet-class>FormDemo</servlet-class>
  </servlet>
   <servlet>
      <servlet-name>CookieServlet</servlet-name>
      <servlet-class>jwadbook.CookieServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>SessionRecordServlet</servlet-name>
      <servlet-class>jwadbook.SessionRecordServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>SessionReaderServlet</servlet-name>
      <servlet-class>jwadbook.SessionReaderServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>DispatcherServlet</servlet-name>
      <servlet-class>jwadbook.DispatcherServlet</servlet-class>
  </servlet>
   <servlet>
      <servlet-name>ServletLogin</servlet-name>
      <servlet-class>jwadbook.ServletLogin</servlet-class>
  </servlet>
  
  <servlet-mapping>
      <servlet-name>DispatcherServlet</servlet-name>
      <url-pattern>/urldispatcher</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
      <servlet-name>HeaderServlet</servlet-name>
      <url-pattern>/head</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
      <servlet-name>Test</servlet-name>
      <url-pattern>/test</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
      <servlet-name>requestcounterservlet</servlet-name>
      <url-pattern>/requestcounterservlet</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
      <servlet-name>FormParameterServlet</servlet-name>
      <url-pattern>/FormParameterServlet</url-pattern>
  </servlet-mapping>
   <servlet-mapping>
      <servlet-name>FormDemo</servlet-name>
      <url-pattern>/FormDemo</url-pattern>
  </servlet-mapping>
   <servlet-mapping>
      <servlet-name>CookieServlet</servlet-name>
      <url-pattern>/CookieServlet</url-pattern>
  </servlet-mapping>
   <servlet-mapping>
      <servlet-name>SessionRecordServlet</servlet-name>
      <url-pattern>/SessionRecordServlet</url-pattern>
  </servlet-mapping>
   <servlet-mapping>
      <servlet-name>SessionReaderServlet</servlet-name>
      <url-pattern>/SessionReaderServlet</url-pattern>
  </servlet-mapping>
   <servlet-mapping>
      <servlet-name>ServletLogin</servlet-name>
      <url-pattern>/login</url-pattern>
  </servlet-mapping>
  
</web-app>

 

这段代码正常启动的了 
但是我加了个filter就启动不了了: 



 <?xml version="1.0" encoding="ISO-8859-1"?>
<web-app version="2.4" 
    xmlns="http://java.sun.com/xml/ns/j2ee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
  <display-name>j2ee test</display-name>
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
 
 <filter>
       <filter-name>FilterServlet</filter-name>
       <filter-class>jwadbook.FilterServlet</filter-class>
       <init-param>
            <param-name>passpwd</param-name>
            <paran-value>12345</param-value>
    </init-param>
</filter> 
<filter-mapping>
       <filter-name>FilterServlet</filter-name>
       <url-pattern>/login</url-pattern>
</filter-mapping>
 
  <servlet>
      <servlet-name>HeaderServlet</servlet-name>
      <servlet-class>HeaderServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>Test</servlet-name>
      <servlet-class>test.Test</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>requestcounterservlet</servlet-name>
      <servlet-class>jwadbook.RequestCounterServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>FormParameterServlet</servlet-name>
      <servlet-class>jwadbook.FormParameterServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>FormDemo</servlet-name>
      <servlet-class>FormDemo</servlet-class>
  </servlet>
   <servlet>
      <servlet-name>CookieServlet</servlet-name>
      <servlet-class>jwadbook.CookieServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>SessionRecordServlet</servlet-name>
      <servlet-class>jwadbook.SessionRecordServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>SessionReaderServlet</servlet-name>
      <servlet-class>jwadbook.SessionReaderServlet</servlet-class>
  </servlet>
  <servlet>
      <servlet-name>DispatcherServlet</servlet-name>
      <servlet-class>jwadbook.DispatcherServlet</servlet-class>
  </servlet>
   <servlet>
      <servlet-name>ServletLogin</servlet-name>
      <servlet-class>jwadbook.ServletLogin</servlet-class>
  </servlet>
 
  
  <servlet-mapping>
      <servlet-name>DispatcherServlet</servlet-name>
      <url-pattern>/urldispatcher</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
      <servlet-name>HeaderServlet</servlet-name>
      <url-pattern>/head</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
      <servlet-name>Test</servlet-name>
      <url-pattern>/test</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
      <servlet-name>requestcounterservlet</servlet-name>
      <url-pattern>/requestcounterservlet</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
      <servlet-name>FormParameterServlet</servlet-name>
      <url-pattern>/FormParameterServlet</url-pattern>
  </servlet-mapping>
   <servlet-mapping>
      <servlet-name>FormDemo</servlet-name>
      <url-pattern>/FormDemo</url-pattern>
  </servlet-mapping>
   <servlet-mapping>
      <servlet-name>CookieServlet</servlet-name>
      <url-pattern>/CookieServlet</url-pattern>
  </servlet-mapping>
   <servlet-mapping>
      <servlet-name>SessionRecordServlet</servlet-name>
      <url-pattern>/SessionRecordServlet</url-pattern>
  </servlet-mapping>
   <servlet-mapping>
      <servlet-name>SessionReaderServlet</servlet-name>
      <url-pattern>/SessionReaderServlet</url-pattern>
  </servlet-mapping>
   <servlet-mapping>
      <servlet-name>ServletLogin</servlet-name>
      <url-pattern>/login</url-pattern>
  </servlet-mapping>
  
</web-app>