Maven文件中配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app   xmlns="http://xmlns.jcp.org/xml/ns/javaee"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
           version="4.0"
           metadata-complete="true">
</web-app>