spring mvc web.xml 配置出現 Attribute "xmlns:xsi" must be declared for element type "web-app"

<span style="font-size:18px;">Multiple annotations found at this line:
	- Attribute "xmlns:xsi" must be declared for element type "web-app".
	- Attribute "xsi:schemaLocation" must be declared for element type "web-app".
	- 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?,mime-mapping*,welcome-file-list?,error-page*,taglib*,resource-env-ref*,resource-ref*,security-
	 constraint*,login-config?,security-role*,env-entry*,ejb-ref*,ejb-local-ref*)".
	- Attribute "version" must be declared for element type "web-app".
	- Attribute "xmlns" must be declared for element type "web-app".</span>

這種錯誤就是需要webapp這個標籤必須是第一行的，前面有註釋文檔都不可以，所以將webapp這個標籤前面的文檔全部刪掉就可以了