@Override
public void doFilter(
ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
throws IOException, ServletException {
HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest;
HttpServletResponse httpServletResponse = (HttpServletResponse) servletResponse;
String url = httpServletRequest.getRequestURI();
httpServletResponse.setHeader(CACHE_HEADER, CacheState.SKIPPED.toString());
if (!isURLAccepted(url)
|| !isQueryStringAccepted(httpServletRequest.getQueryString())
|| !isUserAgentAccepted(httpServletRequest.getHeader(Constants.HTTP_USER_AGENT_HEADER))) {
LOGGER.debug("Skipping Cache filter for: {}?{}", url, httpServletRequest.getQueryString());
LOGGER.debug("URL, QueryString or UserAgent not accepted");
filterChain.doFilter(servletRequest, servletResponse);
return;
}
long now = new Date().getTime();
CacheObject cacheObject = cache.getIfPresent(url);
boolean expireCache = httpServletRequest.getParameter(Constants.PARAM_EXPIRE_CACHE) != null;
if (expireCache) {
LOGGER.trace("Removing Cache for {} due to URL parameter.", url);
cache.invalidate(url);
}
boolean resetCache =
httpServletRequest.getParameter(Constants.PARAM_RESET_CACHE) != null
|| resetTime > 0 && (now - lastResetTime) / 1000 > resetTime;
if (resetCache) {
LOGGER.trace("Resetting whole Cache for {} due to URL parameter.", url);
cache.invalidateAll(); // fixme: we don't need reset since cache values are soft referenced.
lastResetTime = now;
}
boolean skipCache =
httpServletRequest.getParameter(Constants.PARAM_DEBUG) != null
|| httpServletRequest.getParameter(Constants.PARAM_SKIP_CACHE) != null;
if (skipCache) {
filterChain.doFilter(servletRequest, servletResponse);
LOGGER.trace("Skipping Cache for {} due to URL parameter.", url);
return;
}
List<String> requestedResources =
findResourcesToMerge(httpServletRequest.getContextPath(), url);
ServletContext context = filterConfig.getServletContext();
String extensionOrPath = detectExtension(url); // in case of non js/css files it null
if (extensionOrPath == null) {
extensionOrPath =
requestedResources.get(
0); // non grouped i.e. non css/js file, we refer it's path in that case
}
JSCSSMergeServlet.ResourceStatus status =
JSCSSMergeServlet.isNotModified(context, httpServletRequest, requestedResources, false);
if (status.isNotModified()) {
LOGGER.trace("Resources Not Modified. Sending 304.");
cache.invalidate(url);
JSCSSMergeServlet.sendNotModified(
httpServletResponse,
extensionOrPath,
status.getActualETag(),
DEFAULT_EXPIRES_MINUTES,
DEFAULT_CACHE_CONTROL);
return;
}
boolean cacheFound = false;
if (cacheObject != null && cacheObject.getWebUtilitiesResponseWrapper() != null) {
if (requestedResources != null
&& isAnyResourceModifiedSince(requestedResources, cacheObject.getTime(), context)) {
LOGGER.trace("Some resources have been modified since last cache: {}", url);
cache.invalidate(url);
cacheFound = false;
} else {
LOGGER.trace("Found valid cached response.");
// cacheObject.increaseAccessCount();
cacheFound = true;
}
}
if (cacheFound) {
LOGGER.debug("Returning Cached response.");
cacheObject.getWebUtilitiesResponseWrapper().fill(httpServletResponse);
httpServletResponse.setHeader(CACHE_HEADER, CacheState.FOUND.toString());
// fillResponseFromCache(httpServletResponse, cacheObject.getModuleResponse());
} else {
LOGGER.trace("Cache not found or invalidated");
httpServletResponse.setHeader(CACHE_HEADER, CacheState.NOT_FOUND.toString());
WebUtilitiesResponseWrapper wrapper = new WebUtilitiesResponseWrapper(httpServletResponse);
filterChain.doFilter(servletRequest, wrapper);
// some filters return no status code, but we believe that it is "200 OK"
if (wrapper.getStatus() == 0) {
wrapper.setStatus(200);
}
if (isMIMEAccepted(wrapper.getContentType())
&& !expireCache
&& !resetCache
&& wrapper.getStatus() == 200) { // Cache only 200 status response
cache.put(url, new CacheObject(getLastModifiedFor(requestedResources, context), wrapper));
LOGGER.debug("Cache added for: {}", url);
httpServletResponse.setHeader(CACHE_HEADER, CacheState.ADDED.toString());
} else {
LOGGER.trace("Cache NOT added for: {}", url);
LOGGER.trace("is MIME not accepted: {}", isMIMEAccepted(wrapper.getContentType()));
LOGGER.trace("is expireCache: {}", expireCache);
LOGGER.trace("is resetCache: {}", resetCache);
}
wrapper.fill(httpServletResponse);
}
}
