# Known Bugs

When exception `UnavailableException` is thrown from a servlet, response is gets treated like a regular `ServletException`
Some Servlet API's are implemented with limited features since the current protocol used by Apache JServ cannot make function calls to Apache to retrieve information not available at request time. They are: `ServletRequest.getScheme()` - selects only between HTTP/HTTPS. `ServletRequest.getRealPath(String path)` - returns "DOCUMENT_ROOT" + path if available, otherwise null. `ServletContext.getRealPath(String path)` - returns null.
Due to the same protocol restrictions, headers are sent as soon as something is written on the output, preventing any change on them (sessions, cookies). To avoid this, you may buffer your output in your servlet and send it afterwards.
Note: a new version of the protocol (AJPv2.1) will take care of those limited features and Servlet API 2.1 changed getRealPath() behavior to match our needs on multi-tier environments introducing a new resource abstraction. Both of these will are scheduled to be implemented in future versions.

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$Id: bugs.html,v 1.13 1999/06/09 05:21:21 jonbolt Exp $
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