Class CachingExec

  • All Implemented Interfaces:

    public class CachingExec
    extends Object
    implements ClientExecChain

    Request executor in the request execution chain that is responsible for transparent client-side caching.

    The current implementation is conditionally compliant with HTTP/1.1 (meaning all the MUST and MUST NOTs are obeyed), although quite a lot, though not all, of the SHOULDs and SHOULD NOTs are obeyed too.

    Folks that would like to experiment with alternative storage backends should look at the HttpCacheStorage interface and the related package documentation there. You may also be interested in the provided EhCache and memcached storage backends.

    Further responsibilities such as communication with the opposite endpoint is delegated to the next executor in the request execution chain.

    • Method Detail

      • getCacheHits

        public long getCacheHits()
        Reports the number of times that the cache successfully responded to an HttpRequest without contacting the origin server.
        the number of cache hits
      • getCacheMisses

        public long getCacheMisses()
        Reports the number of times that the cache contacted the origin server because it had no appropriate response cached.
        the number of cache misses
      • getCacheUpdates

        public long getCacheUpdates()
        Reports the number of times that the cache was able to satisfy a response by revalidating an existing but stale cache entry.
        the number of cache revalidations
      • execute

        public CloseableHttpResponse execute​(HttpRoute route,
                                             HttpRequestWrapper request,
                                             HttpClientContext context,
                                             HttpExecutionAware execAware)
                                      throws IOException,
        Description copied from interface: ClientExecChain
        Executes th request either by transmitting it to the target server or by passing it onto the next executor in the request execution chain.
        Specified by:
        execute in interface ClientExecChain
        route - connection route.
        request - current request.
        context - current HTTP context.
        execAware - receiver of notifications of blocking I/O operations.
        HTTP response either received from the opposite endpoint or generated locally.
        IOException - in case of a I/O error. (this type of exceptions are potentially recoverable).
        HttpException - in case of an HTTP protocol error (usually this type of exceptions are non-recoverable).
      • supportsRangeAndContentRangeHeaders

        public boolean supportsRangeAndContentRangeHeaders()
        Reports whether this CachingHttpClient implementation supports byte-range requests as specified by the Range and Content-Range headers.
        true if byte-range requests are supported