错误信息为:
- Attribute "xmlns:xsi" must be declared for element type "web-app".
- - Attribute "xsi:schemaLocation" must be declared for element type "web-app".
- Attribute "version" must be declared for element type "web-app".
- - Attribute "xmlns" must be declared for element type "web-app".
解决:原因是<web-app>必须要放在首行,前面不要有注释,如果有删掉,之后按Ctrl+S保存,就没有错误了。