Web.xml基本配置
1. 指定欢迎页
<welcome-file>index.jsp</welcome-file>
2. 命名与定制url
<servlet>
<servlet-name>…</servlet-name>
<servlet-class>…</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>…</servlet-name>
<url-pattern>…</url-pattern>
</servlet-mapping>
3. 定制初始参数
<servlet>
<servlet-name>…</servlet-name>
<servlet-class>…</servlet-class>
<init-param>
<param-name>…</param-name>
<param-value>…</param-value>
</init-param>
</servlet>
注：调用getServletConfig().getInitParameter(“name”),获取参数名对应的值
4. 指定错误处理页面，可以通过“异常类型”或“错误码”来指定错误处理页面
<error-page>
<error-code>404</error-code>
<location>/error404.jsp</location>
</error-page>
5. 设置过滤器
<filter>
< filter -name>…</ filter-name>
< filter -class>…</ filter-class>
</filter >
<filter -mapping>
< filter -name>…</ filter-name>
<url-pattern>…</url-pattern>
</filter -mapping>
6. 设置监听器
<listeren>
<listeren-class>…</listeren-class>
</listeren>
7. 设置session过期时间
<session-config>
<session-timeout>30</session-timeout>
</session-config> | 
转播
