web.xml 详解

1.常规配置：

此处参照CSDN博客：http://blog.csdn.net/cocojiji5/article/details/1601428

每一个站的WEB-INF下都有一个web.xml的设定文件，它提供了我们站台的配置设定.

web.xml定义：
 .站台的名称和说明
 .针对环境参数(Context)做初始化工作
 .Servlet的名称和映射
 .Session的设定
 .Tag library的对映
 .JSP网页设定
 .Mime Type处理
 .错误处理
 .利用JDNI取得站台资源

要了解web.xml的设定值，必须了解它的schema,从web.xml中知道它的schema是由Sum Microsystems公司定制的，如果你想更为详细的了解它，
可以到http://java.sun.com/xml/ns/j2ee/web-mapp_2_5.xsd网页，那里有更为详细的介绍。这里我介绍我们平常见得最都的.
  
<?xml version="1.0" encoding="ISO-8859-1"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
   xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
   version="2.5">

<web-app>
这是一般在写XML时所做的声明,定义了XML的版本，编码格式,还有重要的指明schema的来源,为http://java.sun.com/xml/ns/j2ee
/web-app_2_5.xsd.

<description>,<display-name>,<icon>
____________________________________________

<description>站台描述</discription>
对站台做出描述.

<display-name>站台名称</display-name>
定义站台的名称.

<icon>
icon元素包含small-icon和large-icon两个子元素.用来指定web站台中小图标和大图标的路径.
<small-icon>/路径/smallicon.gif</small-icon>
small-icon元素应指向web站台中某个小图标的路径,大小为16 X 16 pixel,但是图象文件必须为GIF或JPEG格式,扩展名必须为:.gif或
.jpg.

<large-icon>/路径/largeicon-jpg</large-icon>
large-icon元素应指向web站台中某个大图表路径,大小为32 X 32 pixel,但是图象文件必须为GIF或JPEG的格式,扩展名必须为; gif
或jpg.

范例:
<display-name>Develop Example</display-name>
<description>JSP 2.0 Tech Book's Examples</description>
<icon>
   <small-icon>/images/small.gif</small-icon>
   <large-icon>/images/large.gir</large-icon>
</icon>

<distributable>
______________________________________

<distributable>
distributable 元素为空标签,它的存在与否可以指定站台是否可分布式处理.如果web.xml中出现这个元素,则代表站台在开发时已经
被设计为能在多个JSP Container 之间分散执行.
范例:
<distributable/>

 

<context-param>
___________________________________

<context-param>
context-param 元素用来设定web站台的环境参数(context),它包含两个子元素:
param-name和param-value.
<param-name>参数名称</param-name>
设定Context名称
<param-value>值</param-value>
设定Context名称的值
</context-param>
范例:
<context-param>
   <param-name>param_name</param-name>
   <param-value>param_value</param-value>
</context-param>
此所设定的参数,在JSP网页中可以使用下列方法来取得:
${initParam.param_name}
若在Servlet可以使用下列方法来获得:
String param_name=getServletContext().getInitParamter("param_name");

 

<filter>
_________________________________
filter元素用来声明filter的相关设定.filter元素除了下面介绍的的子元素之外,还包括<servlet>介绍过的<icon>,<display-name>
,<description>,<init-param>,其用途一样.
<filter-name>Filter的名称</filter-name>
定义Filter的名称.
<filter-class>Filter的类名称</filter-class>
定义Filter的类名称.例如:com.foo.hello
</filter>

范例:
<filter>
  <filter-name>setCharacterEncoding</filter-name>
  <filter-class>coreservlet.javaworld.CH11.SetCharacterEncodingFilter</filter-class>
  <init-param>
     <param-name>encoding</param-name>
     <param-value>GB2312</param-value>
  </init-param>
</filter>

<filter-mapping>
______________________________________
<filter-mapping>
filter-mapping 元素的两个主要子元素filter-name和url-pattern.用来定义Filter所对应的URL.
<filter-name>Filter的名称</filter-name>
定义Filter的名称.
<url-pattern>URL</url-pattern>
Filter所对应的RUL.例如:<url-pattern>/Filter/Hello</url-pattern>

<servlet-name>Servlet的名称<servlet-name>
定义servlet的名称.
<dispatcher>REQUEST|INCLUDE|FORWARD|ERROR</disaptcher>
设定Filter对应的请求方式,有RQUEST,INCLUDE,FORWAR,ERROR四种,默认为REQUEST.
</filter-mapping>
范例:
<filter-mapping>
   <filter-name>GZIPEncoding</filter-name>
   <url-pattern>/*</url-pattern>
</filter-mapping>

 

<listener>
___________________________________________
<listener>
listener元素用来定义Listener接口,它的主要子元素为<listener-class>
<listen-class>Listener的类名称</listener-class>
定义Listener的类名称.例如: com.foo.hello
<listener>
范例:
<listener>
  <listener-class>coreservlet.javaworld.CH11.ContenxtListener</listener-class>
</listener>

 

<servlet-mapping>
_____________________________________________
servlet-mapping元素包含两个子元素servlet-name和url-pattern.用来定义servlet所对应URL.
<servlet-name>Servlet的名称</servlet-name>
定义Servlet的名称.
<url-pattern>Servlet URL</url-pattern>
定义Servlet所对应的RUL.例如:<url-pattern>/Servlet/Hello</url-pattern>
</servlet-mapping>
范例:
<servlet-mapping>
   <servlet-name>LoginChecker</servlet-name>
   <url-pattern>/LoginChecker</url-pattern>
</servlet-mapping>

<session-cofing>
__________________________________
<session-config>
session-config包含一个子元素session-timeout.定义web站台中的session参数.
<session-timeout>分钟</session-timeout>
定义这个web站台所有session的有效期限.单位为分钟.
</session-config>
范例:
<session-config>
   <session-timeout>20</session-timeout>
</session-config>

<mime-mapping>
___________________________________________________
<mima-mapping>
mime-mapping包含两个子元素extension和mime-type.定义某一个扩展名和某一MIME Type做对映.
<extension>扩展名名称</extension>
扩展名称
<mime-type>MIME格式</mime-type>
MIME格式.
</mime-mapping>
范例:
<mime-mapping>
   <extension>doc</extension>
   <mime-type>application/vnd.ms-word</mime-type>
</mime-mapping>
<mime-mapping>
   <extension>xls</extension>
   <mime-type>application/vnd.ms-excel</mime-type>
</mime-mapping>
<mime-mapping>
   <extension>ppt</extesnion>
   <mime-type>application/vnd.ms-powerpoint</mime-type>
</mime-mapping>

说明：<mime-mapping>主要是用在下载的地方，如果你的web项目没有下载这个模块,<mime-mapping>可以不用配置的，

如果有下载的模块，但是没有配置，那么别人点下载的时候，会打开一个新窗口，而且多数情况下是乱码。有该配置后，就可以用迅雷，flashGet等来下载，也可以目标另存为来下载文件，

在我的之前博客：2010-11-12 “下载的原理" 里面已有详细介绍给块。

<welcome-file-list>
_____________________________________________
<welcome-file-list>
welcome-file-list包含一个子元素welcome-file.用来定义首页列单.
<welcome-file>用来指定首页文件名称</welcome-flie>
welcome-file用来指定首页文件名称.我们可以用<welcome-file>指定几个首页,而服务器会依照设定的顺序来找首页.
范例:
<welcome-file-list>
  <welcome-file>index.jsp</welcome-file>
  <welcome-file>index.htm</welcome-file>
</welcome-file-list>

 

<error-page>
_________________________
<error-page>
error-page元素包含三个子元素error-code,exception-type和location.将错误代码(Error Code)或异常(Exception)的种类对应
到web站台资源路径.
<error-code>错误代码</error-code>
HTTP Error code,例如: 404
<exception-type>Exception</exception-type>
一个完整名称的Java异常类型
<location>/路径</location>
在web站台内的相关资源路径
</error-page>
范例:
<error-page>
   <error-code>404</error-code>
   <location>/error404.jsp</location>
</error-page>
<error-page>
   <exception-type>java.lang.Exception</exception-type>
   <location>/except.jsp</location>
</error-page>

 

<jsp-config>
_______________________________________________
<jsp-config>
jsp-config元素主要用来设定JSP的相关配置,<jsp:config>包括<taglib>和<jsp-property-group>两个子元素.其中<taglib>元素
在JSP 1.2时就已经存在了;而<jsp-property-group>是JSP 2.0新增的元素.

<taglib>
taglib元素包含两个子元素taglib-uri和taglib-location.用来设定JSP网页用到的Tag Library路径.
<taglib-uri>URI</taglib-uri>
   taglib-uri定义TLD文件的URI,JSP网页的taglib指令可以经由这个URI存取到TLD文件.
<taglib-location>/WEB-INF/lib/xxx.tld</taglib-laction>
   TLD文件对应Web站台的存放位置.
</taglib>

<jsp-property-group>
jsp-property-group元素包含8个元素,分别为:
<description>Description</descrition>
此设定的说明

<display-name>Name</display-name>
此设定的名称

<url-pattern>URL</url-pattern>
设定值所影响的范围,如:/CH2 或者/*.jsp

<el-ignored>true|false</el-ignored>
若为true,表示不支持EL语法.

<scripting-invalid>true|false</scripting-invalid>
若为true表示不支持<%scription%>语法.

<page-encoding>encoding</page-encoding>
设定JSP网页的编码

<include-prelude>.jspf</include-prelude>
设置JSP网页的抬头,扩展名为.jspf

<include-coda>.jspf</include-coda>
设置JSP网页的结尾,扩展名为.jspf
</jsp-property-group>
</jsp-config>
范例:
<jsp-config>
<taglib>
   <taglib-uri>Taglib</taglib-uri>
   <taglib-location>/WEB-INF/tlds/MyTaglib.tld</taglib-location>
</taglib>
<jsp-property-group>
   <description>
      Special property group for JSP Configuration JSP example.
   </description>
   <display-name>JSPConfiguration</display-name>
   <uri-pattern>/*</uri-pattern>
   <el-ignored>true</el-ignored>
   <page-encoding>GB2312</page-encoding>
   <scripting-inivalid>true</scripting-inivalid>
   ............
</jsp-property-group>
</jsp-config>

 

<resource-ref>
________________________________________________
<resource-ref>
resource-ref元素包括五个子元素description,res-ref-name,res-type,res-auth,res-sharing-scope.利用JNDI取得站台可
利用资源.
<description>说明</description>
资源说明

<rec-ref-name>资源名称</rec-ref-name>
资源名称

<res-type>资源种类</res-type>
资源种类

<res-auth>Application|Container</res-auth>
资源由Application或Container来许可

<res-sharing-scope>Shareable|Unshareable</res-sharing-scope>
 资源是否可以共享.默认值为 Shareable
范例:
<resource-ref>
   <description>JNDI JDBC DataSource of JSPBook</description>
   <res-ref-name>jdbc/sample_db</res-ref-name>
   <res-type>javax.sql.DataSoruce</res-type>
   <res-auth>Container</res-auth>
</resource-ref>

这些都是些比较常用的,详细可以登录: http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd

 

 

 

2.以前的一个项目Spring MVC + freemarker的web.xml的完整配置：

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
   xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
   version="2.5">

 <display-name>AAAA Web Application</display-name>

 <context-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>
   classpath*:applicationContext-dao.xml
   classpath*:applicationContext-datasource.xml
   classpath:applicationContext-resources.xml
   classpath*:applicationContext-service.xml
   /WEB-INF/applicationContext-filter.xml
   /WEB-INF/applicationContext-security.xml
        </param-value>
 </context-param>

 <context-param>
  <param-name>webAppRootKey</param-name>   
  <param-value>AAAA_web.root</param-value>   
 </context-param>  

 <context-param>
  <param-name>log4jConfigLocation</param-name>
  <param-value>classpath:log4j.properties</param-value>
 </context-param>

 <filter>
  <filter-name>encodingFilter</filter-name>
  <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
  <init-param>
   <param-name>encoding</param-name>
   <param-value>UTF-8</param-value>
  </init-param>
  <init-param>
   <param-name>forceEncoding</param-name>
   <param-value>true</param-value>
  </init-param>
 </filter>

 <filter-mapping>
  <filter-name>encodingFilter</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>
 
 
 <!-- 分发服务器服务、和订购消息服务、暂时屏蔽
 <filter>
  <filter-name>AAAANotifyFilter</filter-name>
  <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
 </filter>
 <filter-mapping>
  <filter-name>AAAANotifyFilter</filter-name>
  <url-pattern>/notify.html</url-pattern>
 </filter-mapping>
 
 <filter>
  <filter-name>AAAACallbackFilter</filter-name>
  <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
 </filter>
 <filter-mapping>
  <filter-name>AAAACallbackFilter</filter-name>
  <url-pattern>/callback.shtml</url-pattern>
 </filter-mapping>
  -->
 <!--
   <filter>
   <filter-name>openSessionInViewFilter</filter-name>
   <filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class>
   </filter>
   <filter-mapping>
   <filter-name>openSessionInViewFilter</filter-name>
   <servlet-name>dispatcher</servlet-name>
   </filter-mapping>
 -->
 <listener>
  <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
 </listener>

 <listener>
  <listener-class>
            org.springframework.web.util.IntrospectorCleanupListener</listener-class>
 </listener>

 <listener>
  <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
 </listener>

 <servlet>
  <servlet-name>dispatcher</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  <load-on-startup>1</load-on-startup>
 </servlet>

 <servlet-mapping>
  <servlet-name>dispatcher</servlet-name>
  <url-pattern>*.html</url-pattern>
  <url-pattern>*.shtml</url-pattern>
  <url-pattern>/track/*</url-pattern>
 </servlet-mapping>

 <!-- <servlet>-->
 <!--    <servlet-name>default</servlet-name>-->
 <!--    <servlet-class>org.mortbay.jetty.servlet.DefaultServlet</servlet-class>-->
 <!--    <init-param>-->
 <!--      <param-name>useFileMappedBuffer</param-name>-->
 <!--      <param-value>false</param-value>-->
 <!--    </init-param>-->
 <!--    <load-on-startup>0</load-on-startup>-->
 <!--  </servlet>-->

 <filter>
  <filter-name>springSecurityFilterChain</filter-name>
  <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
 </filter>

 <filter-mapping>
  <filter-name>springSecurityFilterChain</filter-name>
  <url-pattern>*.shtml</url-pattern>
 </filter-mapping>

 <session-config>
  <session-timeout>30</session-timeout>
 </session-config>

 <error-page>
  <error-code>500</error-code>
  <location>/500.html</location>
 </error-page>
 <error-page>
  <error-code>403</error-code>
  <location>/403.html</location>
 </error-page>
</web-app>

 

3.以前的SSH架构 ，加了spring，加了freemarker的web.xml配置：

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.5" 
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaeehttp://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

 <display-name>网创运营平台</display-name>
 <context-param>
  <!-- spring配置文件 -->
  <param-name>contextConfigLocation</param-name>
  <param-value>classpath:applicationContext.xml</param-value>
 </context-param>

 <!-- Spring Security 
  <filter>
  <filter-name>springSecurityFilterChain</filter-name>
  <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
 </filter>
 <filter-mapping>
  <filter-name>springSecurityFilterChain</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>
 OpenSessionInViewFilter  -->
 <!-- 字符编码过滤器 -->
     <filter>
    <filter-name>encodingFilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>UTF-8</param-value>
    </init-param>
    <init-param>
      <param-name>forceEncoding</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>encodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>
 
 <filter>
  <filter-name>hibernateFilter</filter-name>
  <filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class>
  <init-param>
   <param-name>singleSession</param-name>
   <param-value>true</param-value>
  </init-param>
 </filter>
 <!-- System Auth Filter -->
 <filter>
  <filter-name>AuthFilter</filter-name>
  <filter-class>cn.com.ecenter.system.interceptors.AuthFilter</filter-class>
 </filter>
 <filter>
  <filter-name>osivFilter</filter-name>
  <filter-class>cn.com.ecenter.system.util.OpenSessionInViewFilter</filter-class>
  <init-param>
   <param-name>singleSession</param-name>
   <param-value>true</param-value>
  </init-param>
 </filter>
 <!-- struts2 -->
 <filter>
  <filter-name>struts2</filter-name>
  <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
  <init-param>
   <param-name>actionPackages</param-name>
   <param-value>cn.com.ecenter.dragonclaws.action</param-value>
  </init-param>
 </filter>
 <filter-mapping>
  <filter-name>hibernateFilter</filter-name>
  <url-pattern>*.action</url-pattern>
 </filter-mapping>
 <filter-mapping>
  <filter-name>hibernateFilter</filter-name>
  <url-pattern>*.jsp</url-pattern>
 </filter-mapping>
 
  <filter-mapping>
  <filter-name>hibernateFilter</filter-name>
  <url-pattern>*.shtml</url-pattern>
 </filter-mapping>
 
 
 <filter-mapping>
  <filter-name>AuthFilter</filter-name>
  <url-pattern>*.action</url-pattern>
 </filter-mapping>
 
  <filter-mapping>
  <filter-name>AuthFilter</filter-name>
  <url-pattern>*.shtml</url-pattern>
 </filter-mapping>
 
  <filter-mapping>
  <filter-name>AuthFilter</filter-name>
  <url-pattern>/pages/*</url-pattern>
 </filter-mapping>
 
   <filter-mapping>
  <filter-name>AuthFilter</filter-name>
  <url-pattern>/views/*</url-pattern>
 </filter-mapping>
 
 <filter-mapping>
  <filter-name>osivFilter</filter-name>
  <url-pattern>/system/*</url-pattern>
 </filter-mapping>
 <filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>*.action</url-pattern>
 </filter-mapping>
 <filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>*.jsp</url-pattern>
 </filter-mapping>
 
 
 <!-- Spring Framework -->
 <listener>
  <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
 </listener>
 <!-- ServletContextListener，需要服务器启动时加载的 -->
 <listener>
  <listener-class>cn.com.ecenter.dragonclaws.web.WebContextListerner</listener-class>
 </listener>
 
 <!-- 兼容ftl -->
  <servlet>
    <servlet-name>dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>*.shtml</url-pattern>
    <url-pattern>/track/*</url-pattern>
  </servlet-mapping>
 
 
 
 <servlet>
  <display-name>ElFinderServlet</display-name>
  <servlet-name>ElFinderServlet</servlet-name>
  <servlet-class>cn.com.ecenter.elfinder.ElFinderServlet</servlet-class>
 </servlet>
   <servlet>
 <servlet-name>ShowImageServlet</servlet-name>
    <servlet-class>cn.com.ecenter.dragonclaws.util.ShowImageServlet</servlet-class>
 </servlet>
 <servlet-mapping>
  <servlet-name>ElFinderServlet</servlet-name>
  <url-pattern>/ElFinderServlet</url-pattern>
 </servlet-mapping>
 <servlet-mapping>
   <servlet-name>ShowImageServlet</servlet-name>
   <url-pattern>/ShowImageServlet</url-pattern>
 </servlet-mapping>
 
 <!-- jFreeChart add by xiongt 20110616 -->
   <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>/DisplayChart</url-pattern>
 </servlet-mapping>
 
 <session-config>
  <session-timeout>1200</session-timeout>
 </session-config>
 <!--<jsp-config>
  <jsp-property-group>
   <url-pattern>*.jsp</url-pattern>
   <trim-directive-whitespaces>true</trim-directive-whitespaces>
  </jsp-property-group>
 </jsp-config>-->
 <welcome-file-list>
  <welcome-file>index.jsp</welcome-file>
 </welcome-file-list>
 <login-config>
  <auth-method>BASIC</auth-method>
 </login-config>
</web-app>