/* (non-Javadoc)
* @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
*/
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
ServletRequest req = getRequest(request);
ServletResponse resp = getResponse(request, response);
request.setAttribute(PROCESSED_ATTR, Boolean.TRUE);
chain.doFilter(req, resp);
if (resp instanceof CompressedHttpServletResponseWrapper) {
CompressedHttpServletResponseWrapper compressedResponseWrapper =
(CompressedHttpServletResponseWrapper) resp;
try {
compressedResponseWrapper.close(); // so that stream is finished and closed.
} catch (IOException ex) {
LOGGER.error("Response was already closed: ", ex.toString());
}
if (compressedResponseWrapper.isCompressed()) {
req.setAttribute(COMPRESSED_ATTR, Boolean.TRUE);
}
}
}
private ServletResponse getResponse(ServletRequest request, ServletResponse response) {
if (response.isCommitted() || request.getAttribute(PROCESSED_ATTR) != null) {
LOGGER.trace("No Compression: Response committed or filter has already been applied");
return response;
}
if (!(response instanceof HttpServletResponse) || !(request instanceof HttpServletRequest)) {
LOGGER.trace("No Compression: non http request/response");
return response;
}
HttpServletResponse httpResponse = (HttpServletResponse) response;
HttpServletRequest httpRequest = (HttpServletRequest) request;
String acceptEncoding = httpRequest.getHeader(HTTP_ACCEPT_ENCODING_HEADER);
String contentEncoding = getAppropriateContentEncoding(acceptEncoding);
if (contentEncoding == null) {
LOGGER.trace("No Compression: Accept encoding is : {}", acceptEncoding);
return response;
}
String requestURI = httpRequest.getRequestURI();
if (!isURLAccepted(requestURI)) {
LOGGER.trace("No Compression: For path: ", requestURI);
return response;
}
if (!isQueryStringAccepted(httpRequest.getQueryString())) {
LOGGER.trace("No Compression: For Query String: ", httpRequest.getQueryString());
return response;
}
String userAgent = httpRequest.getHeader(Constants.HTTP_USER_AGENT_HEADER);
if (!isUserAgentAccepted(userAgent)) {
LOGGER.trace("No Compression: For User-Agent: {}", userAgent);
return response;
}
EncodedStreamsFactory encodedStreamsFactory =
EncodedStreamsFactory.getFactoryForContentEncoding(contentEncoding);
LOGGER.debug("Compressing response: content encoding : {}", contentEncoding);
return new CompressedHttpServletResponseWrapper(
httpResponse, encodedStreamsFactory, contentEncoding, compressionThreshold, this);
}