/**
* 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.");
}
}
/**
* This method must be invoked at the end of processing. The streams are closed and their content
* is analyzed. Actual XSLT processing takes place here.
*/
@SuppressWarnings("unchecked")
void finishResponse() throws IOException {
if (writer != null) {
writer.close();
} else {
if (stream != null) stream.close();
}
/*
* If we're not in passthrough mode, then we need to finalize XSLT transformation.
*/
if (false == passthrough) {
if (stream != null) {
final byte[] bytes = ((DeferredOutputStream) stream).getBytes();
final boolean processingSuppressed =
(origRequest.getAttribute(XSLTFilterConstants.NO_XSLT_PROCESSING) != null)
| (origRequest.getParameter(XSLTFilterConstants.NO_XSLT_PROCESSING) != null);
if (processingSuppressed) {
// Just copy the buffered data to the output directly.
final OutputStream os = origResponse.getOutputStream();
os.write(bytes);
os.close();
} else {
// Otherwise apply XSLT transformation to it.
try {
processWithXslt(
bytes,
(Map<String, Object>) origRequest.getAttribute(XSLTFilterConstants.XSLT_PARAMS_MAP),
origResponse);
} catch (TransformerException e) {
final Throwable t = unwrapCause(e);
if (t instanceof IOException) {
throw (IOException) t;
}
filterError("Error applying stylesheet.", e);
}
}
}
}
}
private void detectErrorResponse(int errorCode) {
if (errorCode != HttpServletResponse.SC_ACCEPTED) {
origRequest.setAttribute(XSLTFilterConstants.NO_XSLT_PROCESSING, Boolean.TRUE);
}
}
/**
* Return <code>true</code> if the original request contained XSLT suppressing key.
*
* @see XSLTFilterConstants#NO_XSLT_PROCESSING
*/
private boolean processingSuppressed(HttpServletRequest origRequest2) {
return (origRequest.getAttribute(XSLTFilterConstants.NO_XSLT_PROCESSING) != null)
| (origRequest.getParameter(XSLTFilterConstants.NO_XSLT_PROCESSING) != null);
}