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 {@link HttpCacheStorage} interface and the relatedpackage documentation there. You may also be interested in the provided {@link org.apache.http.impl.client.cache.ehcache.EhcacheHttpCacheStorage EhCache} and {@link org.apache.http.impl.client.cache.memcached.MemcachedHttpCacheStorage memcached} storage backends.
Further responsibilities such as communication with the opposite endpoint is delegated to the next executor in the request execution chain.
@since 4.3