in src/main/java/org/apache/sling/dynamicinclude/CacheControlFilter.java [58:74]
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
ServletException {
final SlingHttpServletRequest slingRequest = (SlingHttpServletRequest) request;
final String resourceType = slingRequest.getResource().getResourceType();
final Configuration config = configurationWhiteboard.getConfiguration(slingRequest, resourceType);
if (config != null && config.hasTtlSet()) {
SlingHttpServletResponse slingResponse = (SlingHttpServletResponse) response;
slingResponse.setHeader(HEADER_CACHE_CONTROL, "max-age=" + config.getTtl());
LOG.debug("set \"{}: max-age={}\" to {}", HEADER_CACHE_CONTROL, config.getTtl(), resourceType);
if (!slingResponse.containsHeader(HEADER_DATE)) {
slingResponse.setDateHeader(HEADER_DATE, System.currentTimeMillis());
}
}
chain.doFilter(request, response);
}