Servlet的web.xml配置文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app 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/javaee
        http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
         version="3.0">

    <!--1.注册servlet 并 创建servlet的请求路径-->
    <!--注册servlet-->
    <servlet>
        <servlet-name>hello</servlet-name>
        <servlet-class>com.kuang.servlet.HelloServlet</servlet-class>
    </servlet>
    <!--servlet的请求路径-->
    <servlet-mapping>
        <servlet-name>hello</servlet-name>
        <url-pattern>/hello</url-pattern>
    </servlet-mapping>

    <!--2.配置web应用初始化出参数-->
    <!--context：上下文-->
    <context-param>
        <param-name>mysqlUrl</param-name>
        <param-value>jdbc:mysql://localhost:3306/mybatis</param-value>
    </context-param>
    
    <!--3.15分钟自动注销session-->
    <session-config>
       <session-timeout>15</session-timeout>
    </session-config>
    
    <!--4.自定义错误页面-->
    <error-page>
       <error-code>404</error-code>
       <location>/error/404.jsp</location>
    </error-page>
    
    <!--5.配置过滤器-->
    <filter>
       <filter-name>filter</filter-name>
       <filter-class>com.kuang.CharacterEncodingFilter</filter-class>
    </filter>
    <filter-mapping>
       <filter-name>filter</filter-name>
       <url-pattern>/servlet/*</url-pattern>
    </filter-mapping>
    
    <!--6.注册监听器-->
    <listener>
       <listener-class>com.kuang.OnlineCountListener</listener-class>
    </listener>
    
    <!--7.设置欢迎页：tomcat启动后不再走 "index.jsp" ,而是进入欢迎页 "login.jsp"-->
    <welcome-file-list>
       <welcome-file>login.jsp</welcome-file>
    </welcome-file-list>
    
</web-app>