web.xml的url映射的小知识:

<url-pattern>/</url-pattern>  会匹配到/login这样的路径型url，不会匹配到模式为*.jsp这样的后缀型url

<url-pattern>/*</url-pattern> 会匹配所有url：路径型的和后缀型的url(包括/login,*.jsp,*.js和*.html等)

案例：

<?xml version="1.0" encoding="UTF-8"?>

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xmlns="http://java.sun.com/xml/ns/javaee"

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"

id="WebApp_ID" version="3.0">

<display-name>Task</display-name>

<!-- <context-param>

<param-name>webAppRootKey</param-name>

<param-value>Task.root</param-value>

</context-param> -->

<!-- spring配置 -->

<context-param>

<param-name>contextConfigLocation</param-name>

<param-value>classpath:spring.xml</param-value>

</context-param>

<!-- 加载spring配置文件：启动spring -->

<listener>

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

</listener>

</web-app>