Support the specification of a content-encoding header for a resource based on file extension

This arose from this discussion on the Tomcat users mailing list:
[http://tomcat.markmail.org/thread/6x7izjf7ltphhh7r](http://tomcat.markmail.org/thread/6x7izjf7ltphhh7r)

Compressed SVG files (*.svgz) require that the server sets the Content-Encoding header so that the user agent correctly renders the response.

I would like to see the Servlet specification extended to allow applications to specify a Content-Encoding header for resources with a given file extension.

Any setting of the Content-Encoding on the response would have to be mindful of any Accept-Encoding header sent by the user agent and the requirements of RFC 2616 section 14.3.

This is very like the element currently used to configure Content-Type.

I see two possible options:

1\. Add support for something along these lines

svgz
gzip

2\. Extend along these lines:

svgz
image/svg+xml
gzip

The second solution seems simpler but element would no longer be limited to MIME type mapping. The first solution is probably a better option.