The content of element type "web-app" must match "(icon?,display- name?,description?,distributable?,context-param*,filter*,filter-mapping*,listener*,servlet*,servlet- mapping*,session-config?

web.xml头部配置： 

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd"> 
<web-app> 

原因：文档内容标签顺序不符合web-app_2_3.dtd规范 

 删除<!DOCTYPE       这段内容 即可