Interface FcHttpClient

All Known Implementing Classes:
ApacheFcHttpClient
public interface FcHttpClient
Frontcache's own origin-fetch abstraction - the extension points' view of "go get this URL". Until 2.8 the three reflection-loaded SPIs (CacheProcessor, IncludeProcessor, FallbackResolver) took an Apache HttpClient in their signatures - the 4.5-era org.apache.http.client.HttpClient. That leaked a third-party type into a public contract: the HttpClient 4.5 -> 5.x upgrade broke every implementation, and so would the next such upgrade. The parameter was only ever threaded through to three leaf calls, and all three mean the same thing - fetch a URL, hand back a WebResponse. Nothing needed a connection pool, a route planner or an entity. So the SPIs take this instead, and the Apache types stay inside ApacheFcHttpClient and the resilience commands. See docs/archive/httpclient5-upgrade-proposal.md section 5.1. The three methods are not redundant - each corresponds to one of those leaf uses, and they differ in ways a caller cannot paper over (which transport, whether a circuit breaker is involved, and whether a non-2xx is an exception or a result). Implementations are supplied by Frontcache; third parties consume this, they do not implement it.

  • Method Details

    • fetch

      WebResponse fetch(String urlStr, Map<String, List<String>> requestHeaders, RequestContext context) throws FrontCacheException
      Fetch through whichever origin transport this node uses: an HTTP call in standalone mode, the origin app's own filter chain in webfilter mode. Resilience-wrapped (circuit breaker, bulkhead, time limiter, fallback).
      Parameters:
      urlStr - absolute origin URL
      requestHeaders - headers to forward; the caller owns the map and it may be mutated
      context - the per-request context this fetch belongs to
      Returns:
      the origin response as a cacheable WebResponse
      Throws:
      FrontCacheException

    • fetchOverHttp

      WebResponse fetchOverHttp(String urlStr, Map<String, List<String>> requestHeaders, RequestContext context) throws FrontCacheException
      Fetch over HTTP specifically, never the filter chain. Includes always use this: an include is a different URL from the one being served, so re-running the current request's filter chain would return the wrong page. Resilience-wrapped like fetch(String, Map, RequestContext).
      Throws:
      FrontCacheException

    • fetch

      WebResponse fetch(String urlStr) throws FrontCacheException
      One-shot GET with no resilience wrapper and no request context - for bootstrap-time downloads such as prefetching fallback pages. The body is materialised into the returned WebResponse, which is fine for the small, few, once-per-startup fetches this is for. Unlike the two request-path methods, a non-2xx status is a normal return, not an exception: callers decide what a 404 on a fallback page means.
      Throws:
      FrontCacheException