/**
* Attempts to send an internal server error HTTP error, if possible. Otherwise simply pushes the
* exception message to the output stream.
*
* @param message Message to be printed to the logger and to the output stream.
* @param t Exception that caused the error.
*/
protected void filterError(String message, Throwable t) {
log.error("XSLT filter error: " + message, t);
if (false == origResponse.isCommitted()) {
// Reset the buffer and previous status code.
origResponse.reset();
origResponse.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
origResponse.setContentType("text/html; charset=UTF-8");
}
// Response committed. Just push the error to the output stream.
try {
final OutputStream os = origResponse.getOutputStream();
final PrintWriter osw = new PrintWriter(new OutputStreamWriter(os, "iso8859-1"));
osw.write("<html><body><!-- " + XSLTFilterConstants.ERROR_TOKEN + " -->");
osw.write("<h1 style=\"color: red; margin-top: 1em;\">");
osw.write("Internal server exception");
osw.write("</h1>");
osw.write("<b>URI</b>: " + origRequest.getRequestURI() + "\n<br/><br/>");
serializeException(osw, t);
if (t instanceof ServletException && ((ServletException) t).getRootCause() != null) {
osw.write("<br/><br/><h2>ServletException root cause:</h2>");
serializeException(osw, ((ServletException) t).getRootCause());
}
osw.write("</body></html>");
osw.flush();
} catch (IOException e) {
// Not much to do in such case (connection broken most likely).
log.debug("Filter error could not be returned to client.");
}
}
