Is there an easy way to map a directory in the web.xml or other deployment descriptor (jetty.xml, etc) files?
For example, if I have a directory /opt/files/ is there
I don't know that you can do that as a URL mapping, however files and folders in the same directory that your web.xml file is in will be accessible in the way you describe, although you can't control the mapping under your webapp.
Does that suit your needs?