Sends an error response to the client using the specified status. The server defaults to creating the response to look like an HTML-formatted server error page containing the specified message, setting the content type to "text/html", leaving cookies and other headers unmodified. If an error-page declaration has been made for the web application corresponding to the status code passed in, it will be served back in preference to the suggested msg parameter.
If the response has already been committed, this method throws an IllegalStateException. After using this method, the response should be considered to be committed and should not be written to.
@param sc the error status code
@param msg the descriptive message
@exception IOException If an input or output exception occurs
@exception IllegalStateException If the response was committed