Class CachingExec

java.lang.Object

org.apache.hc.client5.http.impl.cache.CachingExecBase

org.apache.hc.client5.http.impl.cache.CachingExec

All Implemented Interfaces:

ExecChainHandler

class CachingExec
extends CachingExecBase
implements ExecChainHandler

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

invalid reference

EhCache

and

invalid reference

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

Field Summary

Fields

Modifier and Type	Field	Description
private final DefaultCacheRevalidator	cacheRevalidator
private final ConditionalRequestBuilder<org.apache.hc.core5.http.ClassicHttpRequest>	conditionalRequestBuilder
private static final org.slf4j.Logger	LOG
private final HttpCache	responseCache

Fields inherited from class CachingExecBase

cacheableRequestPolicy, cacheConfig, cacheHits, cacheMisses, cacheUpdates, requestCompliance, responseCachingPolicy, responseCompliance, responseGenerator, suitabilityChecker, SUPPORTS_RANGE_AND_CONTENT_RANGE_HEADERS, validityPolicy, viaHeaders

Constructor Summary

Constructors

Constructor	Description
CachingExec(ResourceFactory resourceFactory, HttpCacheStorage storage, ScheduledExecutorService executorService, SchedulingStrategy schedulingStrategy, CacheConfig config)
CachingExec(HttpCache cache, ScheduledExecutorService executorService, SchedulingStrategy schedulingStrategy, CacheConfig config)
CachingExec(HttpCache responseCache, CacheValidityPolicy validityPolicy, ResponseCachingPolicy responseCachingPolicy, CachedHttpResponseGenerator responseGenerator, CacheableRequestPolicy cacheableRequestPolicy, CachedResponseSuitabilityChecker suitabilityChecker, ResponseProtocolCompliance responseCompliance, RequestProtocolCompliance requestCompliance, DefaultCacheRevalidator cacheRevalidator, ConditionalRequestBuilder<org.apache.hc.core5.http.ClassicHttpRequest> conditionalRequestBuilder, CacheConfig config)
CachingExec(HttpCache cache, DefaultCacheRevalidator cacheRevalidator, CacheConfig config)

Method Summary

Modifier and Type	Method	Description
(package private) org.apache.hc.core5.http.ClassicHttpResponse	cacheAndReturnResponse(org.apache.hc.core5.http.HttpHost target, org.apache.hc.core5.http.HttpRequest request, org.apache.hc.core5.http.ClassicHttpResponse backendResponse, ExecChain.Scope scope, Instant requestSent, Instant responseReceived)
(package private) org.apache.hc.core5.http.ClassicHttpResponse	callBackend(org.apache.hc.core5.http.HttpHost target, org.apache.hc.core5.http.ClassicHttpRequest request, ExecChain.Scope scope, ExecChain chain)
private static org.apache.hc.core5.http.ClassicHttpResponse	convert(SimpleHttpResponse cacheResponse, ExecChain.Scope scope)
org.apache.hc.core5.http.ClassicHttpResponse	execute(org.apache.hc.core5.http.ClassicHttpRequest request, ExecChain.Scope scope, ExecChain chain)	Executes the actual HTTP request.
(package private) org.apache.hc.core5.http.ClassicHttpResponse	handleBackendResponse(org.apache.hc.core5.http.HttpHost target, org.apache.hc.core5.http.ClassicHttpRequest request, ExecChain.Scope scope, Instant requestDate, Instant responseDate, org.apache.hc.core5.http.ClassicHttpResponse backendResponse)
private org.apache.hc.core5.http.ClassicHttpResponse	handleCacheHit(org.apache.hc.core5.http.HttpHost target, org.apache.hc.core5.http.ClassicHttpRequest request, ExecChain.Scope scope, ExecChain chain, HttpCacheEntry entry)
private org.apache.hc.core5.http.ClassicHttpResponse	handleCacheMiss(org.apache.hc.core5.http.HttpHost target, org.apache.hc.core5.http.ClassicHttpRequest request, ExecChain.Scope scope, ExecChain chain)
(package private) org.apache.hc.core5.http.ClassicHttpResponse	negotiateResponseFromVariants(org.apache.hc.core5.http.HttpHost target, org.apache.hc.core5.http.ClassicHttpRequest request, ExecChain.Scope scope, ExecChain chain, Map<String,Variant> variants)
(package private) org.apache.hc.core5.http.ClassicHttpResponse	revalidateCacheEntry(org.apache.hc.core5.http.HttpHost target, org.apache.hc.core5.http.ClassicHttpRequest request, ExecChain.Scope scope, ExecChain chain, HttpCacheEntry cacheEntry)

Methods inherited from class CachingExecBase

clientRequestsOurOptions, explicitFreshnessRequest, generateCachedResponse, generateGatewayTimeout, generateViaHeader, getCacheHits, getCacheMisses, getCacheUpdates, getCurrentDate, getFatallyNonCompliantResponse, handleRevalidationFailure, mayCallBackend, recordCacheFailure, recordCacheHit, recordCacheMiss, recordCacheUpdate, revalidationResponseIsTooOld, setResponseStatus, shouldSendNotModifiedResponse, staleIfErrorAppliesTo, staleResponseNotAllowed, storeRequestIfModifiedSinceFor304Response, supportsRangeAndContentRangeHeaders, unvalidatedCacheHit

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

responseCache

private final HttpCache responseCache

cacheRevalidator

private final DefaultCacheRevalidator cacheRevalidator

conditionalRequestBuilder

private final ConditionalRequestBuilder<org.apache.hc.core5.http.ClassicHttpRequest> conditionalRequestBuilder

LOG

private static final org.slf4j.Logger LOG

Constructor Details

CachingExec

CachingExec(HttpCache cache,
 DefaultCacheRevalidator cacheRevalidator,
 CacheConfig config)

CachingExec

CachingExec(HttpCache responseCache,
 CacheValidityPolicy validityPolicy,
 ResponseCachingPolicy responseCachingPolicy,
 CachedHttpResponseGenerator responseGenerator,
 CacheableRequestPolicy cacheableRequestPolicy,
 CachedResponseSuitabilityChecker suitabilityChecker,
 ResponseProtocolCompliance responseCompliance,
 RequestProtocolCompliance requestCompliance,
 DefaultCacheRevalidator cacheRevalidator,
 ConditionalRequestBuilder<org.apache.hc.core5.http.ClassicHttpRequest> conditionalRequestBuilder,
 CacheConfig config)

CachingExec

CachingExec(HttpCache cache,
 ScheduledExecutorService executorService,
 SchedulingStrategy schedulingStrategy,
 CacheConfig config)

CachingExec

CachingExec(ResourceFactory resourceFactory,
 HttpCacheStorage storage,
 ScheduledExecutorService executorService,
 SchedulingStrategy schedulingStrategy,
 CacheConfig config)

Method Details

execute

public org.apache.hc.core5.http.ClassicHttpResponse execute(org.apache.hc.core5.http.ClassicHttpRequest request,
 ExecChain.Scope scope,
 ExecChain chain)
                                                     throws IOException,
org.apache.hc.core5.http.HttpException

Description copied from interface: ExecChainHandler

Executes the actual HTTP request. The handler can choose to return a response message or delegate request execution to the next element in the execution chain.

Specified by:

execute in interface ExecChainHandler

Parameters:

request - the actual request.

scope - the execution scope .

chain - the next element in the request execution chain.

Throws:

IOException

org.apache.hc.core5.http.HttpException

convert

private static org.apache.hc.core5.http.ClassicHttpResponse convert(SimpleHttpResponse cacheResponse,
 ExecChain.Scope scope)

callBackend

org.apache.hc.core5.http.ClassicHttpResponse callBackend(org.apache.hc.core5.http.HttpHost target,
 org.apache.hc.core5.http.ClassicHttpRequest request,
 ExecChain.Scope scope,
 ExecChain chain)
                                                  throws IOException,
org.apache.hc.core5.http.HttpException

Throws:

IOException

org.apache.hc.core5.http.HttpException

handleCacheHit

private org.apache.hc.core5.http.ClassicHttpResponse handleCacheHit(org.apache.hc.core5.http.HttpHost target,
 org.apache.hc.core5.http.ClassicHttpRequest request,
 ExecChain.Scope scope,
 ExecChain chain,
 HttpCacheEntry entry)
                                                             throws IOException,
org.apache.hc.core5.http.HttpException

Throws:

IOException

org.apache.hc.core5.http.HttpException

revalidateCacheEntry

org.apache.hc.core5.http.ClassicHttpResponse revalidateCacheEntry(org.apache.hc.core5.http.HttpHost target,
 org.apache.hc.core5.http.ClassicHttpRequest request,
 ExecChain.Scope scope,
 ExecChain chain,
 HttpCacheEntry cacheEntry)
                                                           throws IOException,
org.apache.hc.core5.http.HttpException

Throws:

IOException

org.apache.hc.core5.http.HttpException

handleBackendResponse

org.apache.hc.core5.http.ClassicHttpResponse handleBackendResponse(org.apache.hc.core5.http.HttpHost target,
 org.apache.hc.core5.http.ClassicHttpRequest request,
 ExecChain.Scope scope,
 Instant requestDate,
 Instant responseDate,
 org.apache.hc.core5.http.ClassicHttpResponse backendResponse)
                                                            throws IOException

Throws:

IOException

cacheAndReturnResponse

org.apache.hc.core5.http.ClassicHttpResponse cacheAndReturnResponse(org.apache.hc.core5.http.HttpHost target,
 org.apache.hc.core5.http.HttpRequest request,
 org.apache.hc.core5.http.ClassicHttpResponse backendResponse,
 ExecChain.Scope scope,
 Instant requestSent,
 Instant responseReceived)
                                                             throws IOException

Throws:

IOException

handleCacheMiss

private org.apache.hc.core5.http.ClassicHttpResponse handleCacheMiss(org.apache.hc.core5.http.HttpHost target,
 org.apache.hc.core5.http.ClassicHttpRequest request,
 ExecChain.Scope scope,
 ExecChain chain)
                                                              throws IOException,
org.apache.hc.core5.http.HttpException

Throws:

IOException

org.apache.hc.core5.http.HttpException

negotiateResponseFromVariants

org.apache.hc.core5.http.ClassicHttpResponse negotiateResponseFromVariants(org.apache.hc.core5.http.HttpHost target,
 org.apache.hc.core5.http.ClassicHttpRequest request,
 ExecChain.Scope scope,
 ExecChain chain,
 Map<String,Variant> variants)
                                                                    throws IOException,
org.apache.hc.core5.http.HttpException

Throws:

IOException

org.apache.hc.core5.http.HttpException