Javaee file upload
Web.xml error
The error content is as follows:

cvc-id.3: A field of identity constraint ‘web-common-servlet-name-uniqueness’ matched element ‘web-app’, but this element
does not have a simple type.

Solution:

xsi:schemaLocation=”http://java.sun.com/xml/ns/javaee
Change the ‘java’ to uppercase