Web.xml配置说明

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1. web.xml配置详解:

<web-app>
    <!--指定WEB应用的名字-->
    <display-name>MyWeb</display-name>

    <!--WEB应用描述信息-->
    <description>MyWeb demo</description>


    <!--web的初始化参数,通过ServletContextEvent.getServletContext().getInitParameter("field")获得value的值（ServletContextEvent通过listener获得）-->
    <context-param>
        <param-name>contextConfigLocation</para-name>
        <param-value>classpath:applicationContext.xml</param-value>
        <description>web的ApplicationContext上下问文件配置</description>
    </context-param>

    <!--filter 和filter-mapping 必须是成对出现-->

    <!--拦截/*的路径,执行CharacterEncodingFilter的父类的OncePerRequestFilter的doFilter(doFilter中调用doFilterInternal方法,设置request和response的编码方式设置为UTF-8)-->
    <filter>
        <filter-name>utf8-encoding</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>utf8-encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>


    <!--servlet 监听配置，项目启动时执行contextInitialized(ServletContextEvent servletContextEvent)方法，项目停止时执行contextDestroyed(ServletContextEvent event)-->
    <listener>
        <listerner-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>


    <!--servlet和servlet-mapping是成对出现的，服务启动时,执行HttpServlet.init(ServletConfig config)方法,当用户请求/myservlet/*路径时,执行HttpServlet.service(HttpServletRequest req, HttpServletResponse resp)方法-->
    <servlet>
        <servlet-name>myservlet</servlet-name>
        <servlet-class>javax.servlet.http.HttpServlet</servlet-class>
        <init-param>
            <param-name>paramField</param-name>
            <param-value>paramValue</param-value>
        </init-param>
    </servlet>

    <servlet-mapping>
        <servlet-name>myservlet</servlet-name>
        <url-pattern>/myservlet/*</url-pattern>
    </servlet-mapping>

    <!--会话超时时间设置，单位是分钟-->
    <session-config>
        <session-timeout>10</session-timeout>
    </session-config>

    <!--mime-mapping元素将mime类型映射到扩展名, 用于规定下载格式-->
    <mime-mapping>
        <extension>htm</extension>
        <mime-type>text/html</mime-type>
    </mime-mapping>

    <mime-mapping>
        <extension>pdf</extension>
        <mime-type>application/pdf</mime-type>
    </mime-mapping>
    <mime-mapping>
        <extension>doc</extension>
        <mime-type>application/msword</mime-type>
    </mime-mapping>
    <mime-mapping>
        <extension>xls</extension>
        <mime-type>application/msexcel</mime-type>
    </mime-mapping>


    <!--指定Web项目的欢迎页面-->
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>index.html</welcome-file>
    </welcome-file-list>

    <!--当请求发生404错误时，跳转到404error.jsp页面-->
    <error-page>
        <error-code>404</error-code>
        <location>/404error.jsp</location>
    </error-page>

    <!--当Web服务发生java.lang.NullException异常时，跳转到nullerror.jsp页面-->
    <error-page>
        <exception-type>java.lang.NullException</exception-type>
        <location>/nullerror.jsp</location>
    </error-page>

    <!--对tag库文件名称。前端JSP可以通过<%@ taglib uri="http://jakarta.apache.org/tomcat/debug-taglib" prefix="myTag"%>配置使用tag库-->
    <taglib>
        <taglib-uri>http://jakarta.apache.org/tomcat/debug-taglib</taglib-uri>
        <taglib-location>/WEB-INF/tld/taglib.tld</taglib-location>
    </taglib>

    <!--配置资源相关的管理对象,可通过new InitialContext().lookup()获得值-->
    <resource-env-ref>
        <resource-env-ref-name>jms/StockQueue</resource-env-ref-name>
    </resource-env-ref>

    <!--设置factory的外部资源-->
    <resource-ref>
        <description>java JDBC DataSource factory</description>
        <res-ref-name>jdbc/java_db</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>dataManager</res-auth>
    </resource-ref>

    <security-constraint></security-constraint>
    <login-config></login-config>
    <security-role></security-role>
    <env-entry></env-entry>
</web-app>