Any clever ways of handling the context in a web app?

You can use JSTL for creating urls.

For example, <c:url value="/images/header.jpg" /> will prefix the context root.

With CSS, this usually isn’t an issue for me.

I have a web root structure like this:

/css
/images

In the CSS file, you then just need to use relative URLs (../images/header.jpg) and it doesn’t need to be aware of the context root.

As for JavaScript, what works for me is including some common JavaScript in the page header like this:

<script type="text/javascript">
var CONTEXT_ROOT = '<%= request.getContextPath() %>';
</script>

Then you can use the context root in all your scripts (or, you can define a function to build paths – may be a bit more flexible).

Obviously this all depends on your using JSPs and JSTL, but I use JSF with Facelets and the techniques involved are similar – the only real difference is getting the context root in a different way.