I have created Struts2 application using Maven. In this application I have created two namespaces, first is tc and the second one is cmpui. From th
tc
cmpui
You can not access a resources that are under WEB-INF folder. Move your static resources to another place accessible by Struts2 (for example, web root). And use s:url tag to build the URL.
WEB-INF
<link rel="stylesheet" type="text/css" href="<s:url value='/css/default.css'/>">