Spring 项目 web.xml 出错问题解决方案

web.xml会莫名其妙的报错下面这种错误：

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".  
    - Attribute "version" 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 "xmlns" must be declared for element type "web-app". 

解决方案：

原因是标签是必须处在第一行的，删掉标签前面所有的内容，保证标签处在第一行就行了。