maven生成的项目，更改web.xml头成servlet 3.1配置

新建maven project, 选择maven-archetype-webapp, 生成项目 

打开pom.xml中引入3.1的servlet-api

               < servlet.version > 3.1.0 servlet.version >

             

               < dependency >

                      < groupId > javax.servlet groupId >

                      < artifactId > javax.servlet-api artifactId >

                      < version > ${servlet.version} version >

                      < scope > provided scope >

               dependency >

更改web.xml头成一下内容

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

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

        xmlns = "xmlns.jcp.org/xml/ns/javaee"

        xsi:schemaLocation = "xmlns.jcp.org/xml/ns/javaee xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"

        id = "WebApp_ID"

        version = "3.1" >

然后maven update一下

如果出现一下异常信息

Cannot change version of project facet Dynamic Web Module to 3.1.    springmvc        line 1    Maven Java EE Configuration Problem

右键项目， properties->Project Facets 

更改java的版本成1.7或以上， 去掉Dynamic Web Module的勾选, 然后apply 

然后重新勾选Dynamic Web Module， 再选择3.1版本， apply

再次maven update一下， 就OK了