We already specified the encoding in our enclosing JSP page.
<%@ page pageEncoding="UTF-8"%>
as well as specified the charset in the meta header
A common “workaround” is to convert the html to JSP to specify the encoding. However being lazy developers, we want a better solution. Eventually we found the hint to set the encoding in web.xml. We tweaked the extension from .jsp to .html and it works!