Release 4.5.8
-------------------

This is a maintenance release that makes request URI normalization configurable on per request basis
and also ports several improvements in URI handling from HttpCore master.


Changelog:
-------------------

* HTTPCLIENT-1969: Filter out weak cipher suites.
  Contributed by Artem Smotrakov <artem.smotrakov at sap.com>

* HTTPCLIENT-1968: Preserve escaped PATHSAFE characters when normalizing URI path segments.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* HTTPCLIENT-1968: URIBuilder to split path component into path segments when digesting a URI
  (ported from HttpCore master).
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Improved cache key generation (ported from HttpCore master).
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* HTTPCLIENT-1968: added utility methods to parse and format URI path segments (ported
  from HttpCore master).
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* HTTPCLIENT-1968: Make normalization of URI paths optional.
  Contributed by Tamas Cservenak <tamas at cservenak.net>

* Some well known proxies respond with Content-Length=0, when returning 304. For robustness, always use the
  cached entity's content length, as modern browsers do.
  Contributed by Author: Jayson Raymond <jraymond at accelerantmobile.com>



Release 4.5.7
-------------------

This is a maintenance release that corrects Automatic-Module-Name definitions added in the previous
release and fixes a number of minor defects discovered since 4.5.6.

Please note that as of 4.4, HttpClient requires Java 1.6 or newer.

Changelog:
-------------------

* Upgraded HttpCore to version 4.4.11
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* HTTPCLIENT-1960: URIBuilder incorrect handling of multiple leading slashes in path component
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* HTTPCLIENT-1958: PoolingHttpClientConnectionManager to throw ExecutionException in case of a lease operation
  cancellation instead of InterruptedException.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* HTTPCLIENT-1952: Allow default User Agent to be disabled.
  Contributed by Michael Osipov <michaelo at apache.org>

* HTTPCLIENT-1956: CONNECT overwrites the main request object in the HTTP context when requests are executed
  via a proxy tunnel.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* HTTPCLIENT-1940: deprecated SSLSocketFactory made to rethrow SocketTimeoutException as
  ConnectTimeoutException for consistency with non-deprecated code.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Fixed regression in BasicCookieStore serialization.
  Contributed by Author: Mark Mielke <mmielke at ciena.com>

* HTTPCLIENT-1929: Corrected Automatic-Module-Name entries for HttpClient Fluent, HttpClient Windows
  and HttpClient Cache.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* HTTPCLIENT-1927: URLEncodedUtils#parse breaks at double quotes when parsing unquoted values.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* HTTPCLIENT-1939: Update Apache Commons Codec from 1.10 to 1.11
  Contributed by Gary Gregory <ggregory at apache.org>


Release 4.5.6
-------------------

This is a maintenance release that adds Automatic-Module-Name to the manifest for compatibility
with Java 9 Platform Module System and fixes a number of issues discovered since 4.5.5

Please note that as of 4.4, HttpClient requires Java 1.6 or newer.

Changelog:
-------------------

* [HTTPCLIENT-1882=: reset authentication state on I/O or runtime error for connection based
  authentication schemes (such as NTLM)
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1924]: HttpClient to shut down the connection manager if a fatal error occurs
  in the course of a request execution.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Add Automatic-Module-Name in manifest so Java9 modular applications can depend on this library
  Contributed by Varun Nandi <varunkn at amazon.com>

* [HTTPCLIENT-1923]: fixed incorrect connection close on shutdown + fixed corresponding test
  Contributed by Aleksei Arsenev <aarseniev at yandex-team.ru>

* [HTTPCLIENT-1906]: certificates containing alternative subject names other than DNS and IP
  (such as RFC822) get rejected as invalid
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1904]: check cookie domain for null
  Contributed by Hans-Peter Keck <hans-peter.keck at haufe-lexware.com>

* [HTTPCLIENT-1900]: proxy protocol processor does not post-process CONNECT response messages
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1911]: Failing tests on Fedora 28 due to weak encryption algorithms in test
  keystore.
  Contributed by Gary Gregory <ggregory at apache.org> and Michael Simacek <msimacek at redhat dot com>


Release 4.5.5
-------------------

HttpClient 4.5.5 (GA) is a maintenance release that fixes a regression introduced
by the previous release causing a NPE in SystemDefaultCredentialsProvider.

Please note that as of 4.4, HttpClient requires Java 1.6 or newer.

Changelog:
-------------------

* [HTTPCLIENT-1690] Avoid merging Content-Encoding headers coming with 304 status to cache entry.
  Contributed by Sudheera Palihakkara <catchsudheera at gmail.com>

* [HTTPCLIENT-1888] Regression in SystemDefaultCredentialsProvider#getCredentials causing NPE.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1886] Update HttpClient 4.5.x from HttpCore 4.4.7 to 4.4.9
  Contributed by Gary Gregory <ggregory at apache.org>

* [HTTPCLIENT-1889] org.apache.http.client.utils.URLEncodedUtils.parse() 
  should return a new ArrayList when there are no query parameters.
  Contributed by Gary Gregory <ggregory at apache.org>


Release 4.5.4
-------------------

HttpClient 4.5.4 (GA) is a maintenance release that fixes a number of defects found since 4.5.3.

Please note that as of 4.4, HttpClient requires Java 1.6 or newer.

Changelog:
-------------------

* [HTTPCLIENT-1883] SystemDefaultCredentialsProvider to use https.proxy* system properties
  for origins with port 443.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1881] Allow truncated NTLM packets to work with this client.
  Contributed by Karl Wright <DaddyWri at gmail.com>

* [HTTPCLIENT-1855] Disabled caching of DIGEST auth scheme instances due to unreliability of nonce counter
  when the auth cache is shared by multiple sessions.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* BasicCookieStore uses a ReentrantReadWriteLock to avoid synchronization on #getCookies/#toString
  while maintaining thread safety.
  Contributed by Carter Kozak <c4kofony at gmail.com>

* [HTTPCLIENT-1865] DefaultServiceUnavailableRetryStrategy does not respect HttpEntity#isRepeatable.
  Contributed by Tomas Celaya <tjcelaya at joyent dot com>

* [HTTPCLIENT-1859] Encode Content-Disposition name and filename elements appropriately.
  Contributed by Karl Wright <DaddyWri at gmail.com>

* Avoid fetching the cached entity twice on cache hit.
  Contributed by Leandro Nunes <a-lnunes at hotels.com>

* [HTTPCLIENT-1835] #evictExpiredConnections no longer causes the #evictIdleConnections behaviour
  to be implicitly enabled.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1831= URIBuilder should not prepend a leading slash to relative URIs.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1833] Fix Windows Negotiate-NTLM handling of proxies.
  Contributed by Roman Stoffel <roman.stoffel at gamler.info>

* [HTTPCLIENT-1817] Add a "Trust All" TrustStrategy implementation.
  Contributed by Gary Gregory <ggregory at apache.org>

* [HTTPCLIENT-1816] Update Apache Commons Codec 1.9 to 1.10.
  Contributed by Gary Gregory <ggregory at apache.org>

* [HTTPCLIENT-1836] DefaultHostnameVerifier#getSubjectAltNames(X509Certificate) throws java.lang.ClassCastException.
  Contributed by Gary Gregory <ggregory at apache.org>, Ilian Iliev <ilian_iliev at yahoo.com>
  
* [HTTPCLIENT-1845]: Extract InputStreamFactory classes out of GzipDecompressingEntity and 
  DeflateDecompressingEntity for reuse and to create less garbage.
  Contributed by Gary Gregory <ggregory at apache.org>

* [HTTPCLIENT-1847] Update Ehcache from 2.6.9 to 2.6.11.
  Contributed by Gary Gregory <ggregory at apache.org>

* [HTTPCLIENT-1848] Update spymemcached from 2.11.4 to 2.12.3.
  Contributed by Gary Gregory <ggregory at apache.org>

* [HTTPCLIENT-1849] Update JNA from 4.1.0 to 4.4.0.
  Contributed by Gary Gregory <ggregory at apache.org>

* [HTTPCLIENT-1850] Update SLF4J from 1.7.6 to 1.7.25.
  Contributed by Gary Gregory <ggregory at apache.org>


Release 4.5.3
-------------------

HttpClient 4.5.3 (GA) is a maintenance release that fixes a number of defects found since 4.5.2.

Please note that as of 4.4, HttpClient requires Java 1.6 or newer.

Changelog:
-------------------

* [HTTPCLIENT-1803] Improved handling of malformed paths by URIBuilder.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1802] Do not attempt to match SSL host to subject CN if subject alternative name of any type are given.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1788] RFC 6265 policy must not reject cookies with paths that are no prefix of the uri path.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1792] SSLConnectionSocketFactory to throw SSLPeerUnverifiedException with a better error message
  when hostname verification fails.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1779] [OSGi] support NTLM proxy authentication.
  Contributed by Julian Sedding <jsedding@apache.org>

* [HTTPCLIENT-1773] [OSGi] HttpProxyConfigurationActivator does not unregister HttpClientBuilderFactory.
  Contributed by Julian Sedding <jsedding@apache.org>

* [HTTPCLIENT-1771] improve OSGi webconsole display for org.apache.http.proxyconfigurator.
  Contributed by Julian Sedding <jsedding at apache.org>

* [HTTPCLIENT-1770] OSGi metatype for org.apache.http.proxyconfigurator missing factoryPid.
  Contributed by Julian Sedding <jsedding at apache.org>

* [HTTPCLIENT-1767] Null pointer dereference in EofSensorInputStream and ResponseEntityProxy.
  Contributed by Peter Ansell <p_ansell@yahoo.com>

* Support changing system default ProxySelector.
  Contributed by Robin Stevens <stevensro at gmail.com>

* All services registered in the OSGi service registry provide the whole bundle header dictionary as vendor
  property value.
  Contributed by Christoph Fiehe <christoph.fiehe at materna.de>

* [HTTPCLIENT-1750] OSGi support for CachingHttpClientBuilder.
  Contributed by Justin Edelson <justin at justinedelson.com>

* [HTTPCLIENT-1749] OSGi client builder to use weak references to track HttpClient instances.
  Contributed by Justin Edelson <justin at justinedelson.com>

* [HTTPCLIENT-1747] apply RequestConfig defaults when using HttpParams values in backward compatibility mode.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Override LaxRedirectStrategy's INSTANCE field.
  Contributed by Eric Wu <ericwuyi at gmail.com>

* [HTTPCLIENT-1736] do not request cred delegation by default when using Kerberos auth.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1744] normalize hostname and certificate CN when matching to CN.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1732] SystemDefaultCredentialsProvider to take http.proxyHost and http.proxyPort system
  properties into account.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Revert "HTTPCLIENT-1712: SPNego schemes to take service scheme into account when generating auth token".
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1727] AbstractHttpClient#createClientConnectionManager does not account for context class loader.
  Contributed by Charles Allen <charles.allen at metamarkets.com>

* [HTTPCLIENT-1726:] Copy the SNI fix from SSLConnectionSocketFactory to the deprecated SSLSocketFactory class.
  Contributed by David Black <dblack at atlassian.com>


Release 4.5.2
-------------------

HttpClient 4.5.2 (GA) is a maintenance release that fixes a number of minor defects found since 4.5.1.

Please note that as of 4.4, HttpClient requires Java 1.6 or newer.

Changelog:
-------------------

* [HTTPCLIENT-1710, HTTPCLIENT-1718, HTTPCLEINT-1719] OSGi container compatibility improvements.
  Contributed by 212427891 <munene.kiruja at ge.com>

* [HTTPCLIENT-1717] Make fluent API Content#Content(byte[], ContentType) public.
  Contributed by Cash Costello <cash.costello at gmail.com>

* [HTTPCLIENT-1715] NTLMEngineImpl#Type1Message not thread safe but declared as a constant.
  Contributed by Olivier Lafontaine <olafontaine at gmail.com>, Gary Gregory <ggregory at apache.org>

* [HTTPCLIENT-1714] Add HttpClientBuilder#setDnsResolver(DnsResolver).
  Contributed by Alexis Thaveau <alexis.thaveau at gmail.com>

* [HTTPCLIENT-1712] SPNego schemes to take service scheme into account when generating auth token. 
   Contributed by Georg Romstorfer <georg.romstorfer at gmail.com>

* [HTTPCLIENT-1700] Netscape draft, browser compatibility, RFC 2109, RFC 2965 and default cookie 
  specs to ignore cookies with empty name for consistency with RFC 6265 specs.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1704] IgnoreSpec#match to always return false.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1550] Fixed 'deflate' zlib header check.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1698] Fixed matching of IPv6 addresses by DefaultHostnameVerifier
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1695] RFC 6265 compliant cookie spec to ignore cookies with empty name / missing 
  value.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1216] Removed ThreadLocal subclass from DateUtils.
  Contributed by Jochen Kemnade <jochen.kemnade at eddyson.de>

* [HTTPCLIENT-1685] PublicSuffixDomainFilter to ignore local hosts and local domains.
  Contributed by Oleg Kalnichevski <olegk at apache.org>



Release 4.5.1
-------------------

HttpClient 4.5.1 (GA) is a maintenance release that fixes a number of minor defects found since 4.5.

Please note that as of 4.4, HttpClient requires Java 1.6 or newer.

Changelog:
-------------------

* [HTTPCLIENT-1680] redirect of a POST request causes ClientProtocolException.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1673] org.apache.http.entity.mime.content.* missing from OSGi exports.
  Contributed by Benson Margulies <benson at basistech.com>

* [HTTPCLIENT-1668] Fluent request incorrectly handles connect timeout setting.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1667] RequestBuilder does not take charset into account when creating 
  UrlEncodedFormEntity. 
  Contributed by Sergey Smith <smithsv at bk.ru>

* [HTTPCLIENT-1655] HttpClient sends RST instead of FIN ACK sequence when using non-persistant 
  connections.
  Contributed by Oleg Kalnichevski <olegk at apache.org>



Release 4.5
-------------------

HttpClient 4.5 (GA) is a minor feature release that includes several incremental enhancements
to the exisitng functionality such as support for private domains in the Mozilla Public Suffix List.

Changelog:
-------------------

* Reduced default validate after inactivity setting from 5 sec to 2 sec
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1649] Fixed serialization of auth schemes
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1645]: Fluent requests to inherit config parameters of the executor.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1640]: RFC6265 lax cookie policy fails to parse 'max-age' attribute.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1633]: RFC6265CookieSpecProvider compatibility level setting has no effect.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1613]: Support for private domains in Mozilla Public Suffix List.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1651]: Add ability to disable content compression on a request basis
  Contributed by Michael Osipov <michaelo at apache.org>

* [HTTPCLIENT-1654]: Deprecate/remove RequestConfig#decompressionEnabled in favor of #contentCompressionEnabled
  Contributed by Michael Osipov <michaelo at apache.org>



Release 4.4.1
-------------------

HttpClient 4.4.1 (GA) is a maintenance release that fixes a number of defects in new functionality
introduced in version 4.4.

Users of HttpClient 4.4 are encouraged to upgrade.

Please note that as of 4.4, HttpClient requires Java 1.6 or newer.

Changelog:
-------------------

* Marked RFC 2109, RFC 2965, Netscape draft cookie specs as obsolete
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1633] RFC6265CookieSpecProvider compatibility level setting has no effect.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1628]: Auth cache can fail when domain name contains uppercase characters.
  Contributed by Dennis Ju <dejuknow at gmail.com>

* [HTTPCLIENT-1609] Stale connection check in PoolingHttpClientConnectionManager has no effect.
  Internal connection pool does not correctly implement connection validation.
  Contributed by Charles Lip <rene1 at singnet.com.sg>



Release 4.4 Final
-------------------

This is the first stable (GA) release of HttpClient 4.4. Notable features and enhancements included
in 4.4 series are:

* Support for the latest HTTP state management specification (RFC 6265). Please note that the old
cookie policy is still used by default for compatibility reasons. RFC 6265 compliant cookie
policies need to be explicitly configured by the user. Please also note that as of next feature
release support for Netscape draft, RFC 2109 and RFC 2965 cookie policies will be deprecated
and disabled by default. It is recommended to use RFC 6265 compliant policies for new applications
unless compatibility with RFC 2109 and RFC 2965 is required and to migrate existing applications
to the default cookie policy.

* Enhanced, redesigned and rewritten default SSL hostname verifier with improved RFC 2818
compliance

* Default SSL hostname verifier and default cookie policy now validate certificate identity
and cookie domain of origin against the public suffix list maintained by Mozilla.org
<https://publicsuffix.org/list>

* More efficient stale connection checking: indiscriminate connection checking which results
in approximately 20 to 50 ms overhead per request has been deprecated in favor of conditional
connection state validation (persistent connections are to be re-validated only if a specified
period inactivity has elapsed)

* Authentication cache thread-safety: authentication cache used by HttpClient is now thread-safe
and can be shared by multiple threads in order to re-use authentication state for subsequent
requests

* Native Windows Negotiate and NTLM via SSPI through JNA: when running on Windows OS HttpClient
configured to use native NTLM or SPNEGO authentication schemes can make use of platform specific
functionality via JNA and current user credentials. This functionality is still considered
experimental, known to have compatibility issues and subject to change without prior notice.
Use at your discretion.

This release also includes all fixes from the stable 4.3.x release branch.

Please note that as of 4.4, HttpClient requires Java 1.6 or newer.


Changelog:
-------------------

* Support for the latest HTTP state management specification (RFC 6265).
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1515] Caching of responses to HEAD requests
  Contributed by Tyrone Cutajar <tj.cutajar at gmail.com> and
  Francois-Xavier Bonnet <fx at apache.org>

* [HTTPCLIENT-1560] Native Windows auth improvements
  Contributed by Michael Osipov <michaelo at apache.org>

* Update Apache Commons Logging version from 1.1.3 to 1.2.
  Contributed by Gary Gregory <ggregory at apache.org>

* Update Apache Commons Codec version from 1.6 to 1.9.
  Contributed by Gary Gregory <ggregory at apache.org>

* Update Ehcache version from 2.2.0 to 2.6.9.
  Contributed by Gary Gregory <ggregory at apache.org>

* Update Ehcache version from 2.2.0 to 2.6.9.
  Contributed by Gary Gregory <ggregory at apache.org>

* Update Spymemcached version from 2.6 to 2.11.4.
  Contributed by Gary Gregory <ggregory at apache.org>

* Update SLF4J version from 1.5.11 to 1.7.7.
  Contributed by Gary Gregory <ggregory at apache.org>





Release 4.4 BETA1
-------------------

This is the first BETA release of HttpClient 4.4. Notable features and enhancements included
in 4.4 series are:

* Enhanced redesigned and rewritten default SSL hostname verifier with improved RFC 2818
compliance

* Default SSL hostname verifier and default cookie policy now validate certificate identity
and cookie domain of origin against the public suffix list maintained by Mozilla.org
<https://publicsuffix.org/list>

* Native windows Negotiate/NTLM via JNA: when running on Windows OS HttpClient configured to use
native NTLM or SPNEGO authentication schemes can make use of platform specific functionality
via JNA and current user system credentials

* More efficient stale connection checking: indiscriminate connection checking which results
in approximately 20 to 50 ms overhead per request has been deprecated in favor of conditional
connection state validation (persistent connections are to be re-validated only if a specified
period inactivity has elapsed)

* Authentication cache thread-safety: authentication caches used by HttpClient is now thread-safe
and can be shared by multiple threads in order to re-use authentication state for subsequent
requests

This release also includes all fixes from the stable 4.3.x release branch.

Please note that as of 4.4, HttpClient requires Java 1.6 or newer.


Changelog:
-------------------

* [HTTPCLIENT-1547] HttpClient OSGi bundle doesn't import the package "javax.naming".
  Contributed by Willem Jiang <ningjiang at apache.org>

* [HTTPCLIENT-1541] Use correct (HTTP/hostname) service principal name for Windows native
  Negotiate/NTLM auth schemes.
  Contributed by Ka-Lok Fung <ka-lok.fung at sap.com>

* Improved compliance with RFC 2818: default hostname verifier to ignore the common name of the
  certificate subject if alternative subject names (dNSName or iPAddress) are present.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1540] Support delegated credentials (ISC_REQ_DELEGATE) by Native windows
  native Negotiate/NTLM auth schemes.
  Contributed by Ka-Lok Fung <ka-lok.fung at sap.com>



Release 4.4 ALPHA1
-------------------

This is the first ALPHA release of HttpClient 4.4. Notable features and enhancements included
in the 4.4 branch are:

* More efficient stale connection checking: indiscriminate connection checking which results
in approximately 20 to 50 ms overhead per request has been deprecated in favor of conditional
connection state validation (persistent connections are to be re-validated only if a specified
period inactivity has elapsed)

* Native windows Negotiate/NTLM via JNA: when running on Windows OS HttpClient configured to use
native NTLM or SPNEGO authentication schemes can make use of platform specific functionality
via JNA and current user system credentials

* Authentication cache thread-safety: authentication caches used by HttpClient is now thread-safe
and can be shared by multiple threads in order to re-use authentication state for subsequent
requests

This release also includes all fixes from the stable 4.3.x release branch.

Please note that as of 4.4, HttpClient requires Java 1.6 or newer.

Please note that new features included in this release are still considered experimental and
their API may change in the future 4.4 alpha and beta releases.


Changelog:
-------------------

* [HTTPCLIENT-1493] Indiscriminate connection checking has been deprecated in favor of conditional
  connection state validation. Persistent connections are to be re-validated only after a defined
  period inactivity prior to being leased to the consumer.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1519] Use the original HttpHost instance passed as a parameter to
  HttpClient#execute when generating 'Host' request header.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1491] Enable provision of Service Principal Name in Windows native
  auth scheme.
  Contributed by Malcolm Smith <malcolmfsmith at gmail.com>

* [HTTPCLIENT-1403] Pluggable content decoders.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1466] FileBodyPart#generateContentType() ignores custom ContentType values.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1461] fixed performance degradation in gzip encoded content processing
  introduced by HTTPCLIENT-1432.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1457] Incorrect handling of Windows (NT) credentials by
  SystemDefaultCredentialsProvider.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1456] Request retrial after status 503 causes ClientProtocolException.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1454] Make connection operator APIs public.
  Contributed by Tamas Cservenak <tamas at cservenak.net>

* Update JUnit to version 4.11 from 4.9
  Contributed by Gary Gregory <ggregory at apache.org>



Release 4.3.4
-------------------

HttpClient 4.3.4 (GA) is a maintenance release that improves performance in high concurrency
scenarios. This version replaces dynamic proxies with custom proxy classes and eliminates thread
contention in java.reflect.Proxy.newInstance() when leasing connections from the connection pool
and processing response messages.


Changelog:
-------------------

* Replaced dynamic proxies with custom proxy classes to reduce thread contention.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1484] GzipCompressingEntity should not close the underlying output stream
  if the entity has not been fully written out due to an exception.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1474] Fixed broken entity enclosing requests in HC Fluent.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1470] CachingExec(ClientExecChain, HttpCache, CacheConfig, AsynchronousValidator)
  throws NPE if config is null




Release 4.3.3
-------------------

HttpClient 4.3.3 (GA) is a bug fix release that fixes a regression introduced by the previous
release causing a significant performance degradation in compressed content processing.

Users of HttpClient 4.3 are encouraged to upgrade.

Changelog:
-------------------

* [HTTPCLIENT-1466] FileBodyPart#generateContentType() ignores custom ContentType values.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1453] Thread safety regression in PoolingHttpClientConnectionManager
  #closeExpiredConnections that can lead to ConcurrentModificationException.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1461] fixed performance degradation in compressed content processing
  introduced by HTTPCLIENT-1432.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1457] Incorrect handling of Windows (NT) credentials by
  SystemDefaultCredentialsProvider.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1456] Request retrial after status 503 causes ClientProtocolException.
  Contributed by Oleg Kalnichevski <olegk at apache.org>


Release 4.3.2
-------------------

HttpClient 4.3.2 (GA) is a maintenance release that delivers a number of improvements
as well as bug fixes for issues reported since 4.3.1 release. SNI support for
Oracle JRE 1.7+ is being among the most notable improvements.

Users of HttpClient 4.3 are encouraged to upgrade.

Changelog:
-------------------

* [HTTPCLIENT-1447] Clients created with HttpClients.createMinimal do not work with absolute URIs
  Contributed by Joseph Walton <joe at kafsemo dot org>

* [HTTPCLIENT-1446] NTLM proxy + BASIC target auth fails with 'Unexpected state:
  MSG_TYPE3_GENERATED'.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1443] HttpCache uses the physical host instead of the virtual host as a cache key.
  Contributed by Francois-Xavier Bonnet <fx at apache.org>

* [HTTPCLIENT-1442] Authentication header set by the user gets removed in case
  of proxy authentication (affects plan HTTP requests only).
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1441] Caching AsynchronousValidationRequest leaks connections.
  Contributed by Dominic Tootell <dominic.tootell at gmail.com>

* [HTTPCLIENT-1440] 'file' scheme in redirect location URI causes NPE.
  Contributed by James Leigh <james at 3roundstones dot com>

* [HTTPCLIENT-1437] Made Executor#execute thread safe.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1119] SNI support (Oracle Java 1.7+ only).
  Contributed by Bruno Harbulot <bruno at distributedmatter.net>

* [HTTPCLIENT-1435] Fluent Executor ignores custom request properties.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1432] Lazy decompressing of HttpEntity#getContent() to avoid EOFException
  in case of an empty response with 'Content-Encoding: gzip' header.
  Contributed by Yihua Huang <code4crafter at gmail.com>

* [HTTPCLIENT-1431] (Regression) deprecated connection manager cannot be used with
  a custom LayeredSchemeSocketFactory.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1425] Fixed socket closed exception thrown by caching HttpClient when the origin
  server sends a long chunked response.
  Contributed by James Leigh <james at 3roundstones dot com>

* [HTTPCLIENT-1417] Fixed NPE in BrowserCompatSpec#formatCookies caused by version 1
  cookies with null cookie value.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1416] Fixed NPE in CachingHttpClientBuilder#build().
  Contributed by Oleg Kalnichevski <olegk at apache.org>



Release 4.3.1
-------------------

HttpClient 4.3.1 (GA) is a bug fix release that addresses a number of issues reported since
release 4.3.

Users of HttpClient 4.3 are strongly encouraged to upgrade.

Changelog
-------------------

* [HTTPCLIENT-1410] Browser compatible hostname verifier no longer rejects
  *.co.<countrycode>, *.gov.<countrycode>, *.info.<countrycode>, etc as invalid.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Ensure X509HostnameVerifier is never null.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1405] CONNECT HTTP/1.1 requests lack mandatory 'Host' header.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1402] Cache default User-Agent value.
  Contributed by yuexiaojun <junedo at qq.com>

* [HTTPCLIENT-1398] Fixed invalid OSGi metadata caused by corrupted Maven bundle plugin metadata.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1399] Fixed NPE in RequestBuilder.
  Contributed by Oleg Kalnichevski <olegk at apache.org>




Release 4.3 Final
-------------------

This is the first stable (GA) release of HttpClient 4.3. The most notable enhancements included
in this release are:

* Support for Java 7 try-with-resources for resource management (connection release.)

* Added fluent Builder classes for HttpEntity, HttpRequest, HttpClient and SSLContext instances.

* Deprecation of preference and configuration API based on HttpParams interface in favor of
constructor injection and plain configuration objects.

* Reliance on object immutability instead of access synchronization for thread safety.
Several old classes whose instances can be shared by multiple request exchanges have
been replaced by immutable equivalents.

* DefaultHttpClient,  DecompressingHttpClient, CachingHttpClient and similar classes are
deprecated in favor of builder classes that produce immutable HttpClient instances.

* HttpClient builders now dynamically construct a request execution pipeline tailored
specifically to the user configuration by physically excluding unnecessary protocol components.

* There is now an option to construct a minimal HttpClient implementation that can only execute
basic HTTP message exchanges without redirects, authentication, state management or proxy support.
This feature might be of particular use in web crawler development.

* There is now option to avoid strict URI syntax for request URIs by executing HTTP requests
with an explicitly specified target host. HttpClient will no longer attempt to parse the request
URI if it does not need to extract the target host from it.

This release also includes all fixes from the stable 4.2.x release branch.


Changelog
-------------------
* [HTTPCLIENT-1371] Weak ETag Validation is Useful On PUT With If-Match
  Contributed by James Leigh <james at 3roundstones dot com>

* [HTTPCLIENT-1394] Support for Native windows Negotiate/NTLM via JNA
  Contributed by Ryan McKinley <ryan at apache.org>

* [HTTPCLIENT-1384] Expose CacheInvalidator interface.
  Contributed by Nicolas Richeton <nicolas.richeton at free.fr>

* [HTTPCLIENT-1385] Fixed path normalization in CacheKeyGenerator
  Contributed by James Leigh <james at 3roundstones dot com>

* [HTTPCLIENT-1370] Response to non-GET requests should never be cached with the default
  ResponseCachingPolicy
  Contributed by James Leigh <james at 3roundstones dot com>

* [HTTPCLIENT-1373] OPTIONS and TRACE should not invalidate cache
  Contributed by James Leigh <james at 3roundstones dot com>

* [HTTPCLIENT-1383] HttpClient enters an infinite loop during NTLM authentication if the opposite
  endpoint keeps responding with a type 2 NTLM response after type 3 MTLM message has already been
  sent by the client.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1372] Refactor HttpMultipart, and add RFC6532 mode, so that headers in post
  are no longer constrained to ASCII values.
  Contributed by Karl Wright <kwright at apache.org>

* [HTTPCLIENT-1377] User principal for non-NTLM authentication is incorrectly generated when using
  user credentials are specified as NTCredentials
  Contributed by Gary Gregory <ggregory at apache.org>



Release 4.3 BETA2
-------------------

This is the second BETA release of HttpClient 4.3. The most notable features and improvements
in the 4.3 branch are: Support for Java 7  try-with-resources for resource management (connection
release); fluent Builder classes for HttpEntity, HttpRequest and HttpClient instances, deprecation
of preference and configuration API based on HttpParams interface in favor of constructor injection
and plain configuration objects, reliance on object immutability instead of access synchronization
for thread safety.

This release also includes all fixes from the stable 4.2.x release branch.

Changelog
-------------------


* [HTTPCLIENT-1366] org.apache.http.client.utils.URLEncodedUtils should parse the semicolon as a query parameter separator.
  Contributed by Gary Gregory <ggregory at apache.org>

* [HTTPCLIENT-1365] NPE when ManagedHttpClientConnectionFactory.create(ConnectionConfig) is called with null.
  Contributed by Gary Gregory <ggregory at apache.org>

* [HTTPCLIENT-1362] Better error messages for connect timed out and connection refused
  exceptions.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1360] separate out DeflateInputStream as an independent class,
  so it can be used by others.
  Contributed by Karl Wright <kwright at apache.org>

* [HTTPCLIENT-1359] repeated requests using the same context fail if they redirect.
  Contributed by James Leigh <james at 3roundstones.com>

* [HTTPCLIENT-1354] do not quote algorithm parameter in DIGEST auth response.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1351] Added utility method to resolve final location from original request,
  target host and a list of redirects.
  Contributed by James Leigh <james at 3roundstones.com>

* [HTTPCLIENT-1344] Userinfo credentials in URI should not default to preemptive BASIC
  authentication.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1345] Useinfo credentials ignored in redirect location header.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1294] HttpClient to rewrite host name of the redirect location URI in order
  to avoid circular redirect exception due to host name case mismatch.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1264] Add support for multiple levels of browser compatibility
  to BrowserCompatSpec and BrowserCompatSpecFactory.  Include constructor
  argument for IE medium-security compatibility.
  Contributed by Karl Wright (kwright at apache.org)

* [HTTPCLIENT-1349] SSLSocketFactory incorrectly identifies key passed with keystore as
  the keystore password.
  Contributed by David Graff <djgraff209 at gmail.com>

* [HTTPCLIENT-1346] Ensure propagation of SSL handshake exceptions.
  Contributed by Pasi Eronen <pe at iki.fi>

* [HTTPCLIENT-1343] SSLSocketFactory optional parameters for supported SSL protocols and cipher
  suites.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1238] Contribute Bundle Activator And Central Proxy Configuration.
  Contributed by Simone Tripodi <simonetripodi at apache.org>

* [HTTPCLIENT-1299] (regression) cache incorrectly disposes of the underlying cache resource
  when storing variant entry.
  Contributed by James Leigh <james at 3roundstones.com>

* [HTTPCLIENT-1342] Redirects with underscore character in the location hostname cause
  "java.lang.IllegalArgumentException: Host name may not be null".
  Contributed by Oleg Kalnichevski <olegk at apache.org>



Release 4.3 BETA1
-------------------

This is the first BETA release of HttpClient 4.3. The 4.3 branch enhances HttpClient in several
key areas and includes several notable features and improvements: Support for Java 7
try-with-resources for resource management (connection release); fluent Builder classes for
HttpEntity, HttpRequest and HttpClient instances, deprecation of preference and configuration API
based on HttpParams interface in favor of constructor injection and plain configuration objects,
reliance on object immutability instead of access synchronization for thread safety.

This release also includes all fixes from the stable 4.2.x release branch.


Changelog
-------------------

* [HTTPCLIENT-1317] InetAddressUtils should handle IPv6 Addresses with Embedded IPv4 Addresses
  Contributed Sebastian Bazley <sebb at apache.org>.

* [HTTPCLIENT-1320] Leverage javax.net.ssl.SSLSocketFactory#getDefault() to initialize SSL context
  based on system defaults instead of using an internal custom routine.
  Contributed by Abe Backus <abraham at backus.com> and Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1316] Certificate verification rejects IPv6 addresses which are not String-equal.
  Contributed Sebastian Bazley <sebb at apache.org>.

* [HTTPCLIENT-1307] Future based asynchronous request execution.
  Contributed by Jilles van Gurp <jilles at jillesvangurp.com>

* [HTTPCLIENT-1313] Fixed IllegalStateException in deprecated ThreadSafeClientConnManager.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1298] Add AsynchronousValidator in HttpClientBuilder's list of closeable objects.
  Contributed by Martin Meinhold <mmeinhold at atlassian.com>



Release 4.3 ALPHA1
-------------------

This is the first ALPHA release of HttpClient 4.3. The 4.3 branch enhances HttpClient in several
key areas and includes several notable features and improvements: Support for Java 7
try-with-resources for resource management (connection release); fluent Builder classes for
HttpEntity, HttpRequest and HttpClient instances, deprecation of preference and configuration API
based on HttpParams interface in favor of constructor injection and plain configuration objects,
reliance on object immutability instead of access synchronization for thread safety.

We are kindly asking all upstream projects to review API changes and help us improve
the APIs by providing feedback and sharing ideas on dev@hc.apache.org.

This release also includes all fixes from the stable 4.2.x release branch.

Please note that new features included in this release are still considered experimental and
their API may change in the future 4.3 alpha and beta releases.


Changelog
-------------------

* [HTTPCLIENT-1250] Allow query string to be ignored when determining cacheability for
  HTTP 1.0 responses.
  Contributed by Don Brown <mrdon at twdata.org>

* [HTTPCLIENT-1261] Make SystemDefaultHttpClient honor http.agent system property.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-900] Don't enforce URI syntax for messages with an explicit target host.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1190] HttpClient cache does not support "Vary: Cookie"
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1259] Calling #abort() on requests executed with DecompressingHttpClient has no
  effect.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1253] URIBuilder setParameter() method could exceed the HTTP header size.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1216] Added method to force clean thread-local used by DateUtils.
  Contributed by Oleg Kalnichevski <olegk at apache.org>


Release 4.2.3
-------------------

HttpClient 4.2.3 (GA) is a bug fix release that addresses a number of issues reported since
release 4.2.2. This release also includes a thoroughly reworked NTLM authentication engine
which should result in a better compatibility with the newest Microsoft products.

Users of HttpClient 4.x are advised to upgrade.

Changelog
-------------------

* [HTTPCLIENT-1296] NPE gets thrown if you combine a default host with a virtual host
  that has a -1 value for the port.
  Contributed by Karl Wright <daddywri at gmail.com>

* [HTTPCLIENT-1290] 304 cached response never reused with If-modified-since conditional
  requests.
  Contributed by Francois-Xavier Bonnet <francois-xavier.bonnet at centraliens.net>

* [HTTPCLIENT-1291] Absolute request URIs without an explicitly specified path are rewritten
  to have "/" path).
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1286] Request URI rewriting is inconsistent - URI fragments are not removed
  from absolute request URIs.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1284] HttpClient incorrectly generates Host header when physical connection
  route differs from the host name specified in the request URI.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1293] Kerberos and SPNego auth schemes use incorrect authorization header name
  when authenticating with a proxy.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1283] NTLM needs to use Locale-independent form of
  toUpperCase().
  Contributed by Karl Wright <DaddyWri at gmail.com>

* [HTTPCLIENT-1279] Target host responding with status 407 (proxy authentication required)
  causes an NPE.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1281] GzipDecompressingEntity does not release InputStream when an IOException
  occurs while reading the Gzip header
  Contributed by Francois-Xavier Bonnet <francois-xavier.bonnet at centraliens.net>

* [HTTPCLIENT-1277] Caching client sends a 304 to an unconditional request.
  Contributed by Francois-Xavier Bonnet <francois-xavier.bonnet at centraliens.net>

* [HTTPCLIENT-1278] Update NTLM documentation.
  Contributed by Karl Wright <DaddyWri at gmail.com>

* SystemDefaultHttpClient misinterprets 'http.keepAlive' default value and disables
  connection persistence if the system property is not set. This causes connection
  based authentication schemes such as NTLM to fail.

* [HTTPCLIENT-1276] cache update on a 304 response causes NPE.
  Contributed by Francois-Xavier Bonnet <francois-xavier.bonnet at centraliens.net>

* [HTTPCLIENT-1273] DecompressingHttpClient does not automatically consume response
  content in case of an i/o, HTTP or runtime exception thrown by the decompressing
  protocol interceptor leading to a potential connection leak.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1268] NTLM engine refactor fix, to correct a buffer overrun, and get NTLMv2
  flags right.
  Contributed by Karl Wright <DaddyWri at gmail.com>

* [HTTPCLIENT-1266] NTLM engine refactoring and compatibility improvements.
  Contributed by Karl Wright <DaddyWri at gmail.com>

* [HTTPCLIENT-1263] BrowserCompatSpec: attribute values containing spaces or special characters
  should be enclosed with quotes marks for version 1 cookies.
  Contributed by Francois-Xavier Bonnet <francois-xavier.bonnet at centraliens.net>

* [HTTPCLIENT-1263] CachingHttpClient fails to release connections back to the connection
  manager for some type of HTTP response messages when used together with DecompressingHttpClient.
  Contributed by Francois-Xavier Bonnet <francois-xavier.bonnet at centraliens.net>

* [HTTPCLIENT-1258] Fixed NullPointerException in NTLMEngineImpl caused by null NT domain
  attribute.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1254] Redirect with underscore in hostname causes ProtocolException.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1255] AbstractVerifier incorrectly parses certificate CN containing wildcard.
  Contributed by Oleg Kalnichevski <olegk at apache.org>



Release 4.2.2
-------------------

HttpClient 4.2.2 (GA) is a bug fix release that addresses a number of issues reported since
release 4.2.1.

Users of HttpClient 4.2 are advised to upgrade.

Changelog
-------------------

* [HTTPCLIENT-1248] Default and lax redirect strategies should not convert requests redirected
  with 307 status to GET method.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1215] BasicAuthCache does not take default ports into consideration when
  looking up cached authentication details by HttpHost key.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1241] (regression) Preemptive BASIC authentication failure should be considered
  final and no further attempts to re-authenticate using the same credentials should be made.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1229] Fixed NPE in BasicClientConnectionManager that can be triggered by releasing
  connection after the connection manager has already been shut down.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1227] Date parsing in DateUtils made more efficient.
  Contributed by Patrick Linskey <pcl at apache.org>

* [HTTPCLIENT-1224] (regression) NTLM auth not retried after a redirect over a non-persistent
  connection.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1223] Cache could be more aggressive on cache invalidations
  from Content-Location. Contributed by Jon Moore <jonm at apache.org>.
  Contributed by Jon Moore <jonm at apache.org>

* [HTTPCLIENT-1217] AutoRetryHttpClient does not release connection used by the previous response
  when request is retried
  Contributed by Oleg Kalnichevski <olegk at apache.org>



Release 4.2.1
-------------------

HttpClient 4.2.1 (GA) is a bug fix release that addresses a number of issues reported since
release 4.2.

Users of HttpClient 4.2 are advised to upgrade.

Changelog
-------------------

* [HTTPCLIENT-1209] Redirect URIs are now normalized.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1202] ResponseCachingPolicy should honor explicit cache-control
  directives for other status codes
  Contributed by Jon Moore <jonm at apache.org>

* [HTTPCLIENT-1199] DecompressingHttpClient strips content from entity enclosing requests
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1198] HttpHost is not set in HttpContext in CachingHttpClient.
  Contributed by Jon Moore <jonm at apache.org>

* [HTTPCLIENT-1200] DecompressingHttpClient fails to generate correct HttpHost context attribute.
  Contributed by Guillaume Castagnino <casta+jira at xwing.info>

* [HTTPCLIENT-1192] URIBuilder encodes query parameters twice.
  Contributed by Oleg Kalnichevski <olegk at apache.org> and Sebastian Bazley <sebb at apache.org>.

* [HTTPCLIENT-1196] Fixed NPE in UrlEncodedFormEntity constructor thrown if charset is null.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1193] Fixed regression in the route tracking logic of the default connection manager
  causing cross-site redirect failures.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

Release 4.2
-------------------

This is the first stable (GA) release of HttpClient 4.2. The most notable enhancements included
in this release are:

* New facade API for HttpClient based on the concept of a fluent interface. The fluent API exposes
  only the most fundamental functions of HttpClient and is intended for relatively simple use cases
  that do not require the full flexibility of HttpClient. However, the fluent API almost fully
  relieves the users from having to deal with connection management and resource deallocation.

* Redesigned and rewritten connection management code.

* Enhanced HTTP authentication API that enables HttpClient to handle more complex authentication
  scenarios. HttpClient 4.2 is now capable of making use of multiple authentication challenges
  and retry authentication with a fall-back scheme in case the primary one fails. This can be
  important for compatibility with Microsoft products that are often configured to use
  SPNEGO/Kerberos as the preferred authentication scheme.


Changelog
-------------------

* [HTTPCLIENT-1187] If a revalidation response is deemed too old CachingHttpClient fails to
  consume its content resulting in a connection leak.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1186] State of newly created connections in the connection pool is not always
  correctly updated potentially allowing those connections to be leased to users with a different
  security context.
  Contributed by Ralf Poehlmann <rpn at methodpark.de>

* [HTTPCLIENT-1179] Upgraded Commons Codec dependency to version 1.6
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1177] always remove fragments from request URIs
  Contributed by Oleg Kalnichevski <olegk at apache.org>

Incompatible changes
--------------------
[Compared to release version 4.1.3]

The following fields have been deprecated for some time now and have been deleted:

org.apache.http.client.params.ClientPNames#CONNECTION_MANAGER_FACTORY
org.apache.http.impl.cookie.BrowserCompatSpec#DATE_PATTERNS

The following methods have been deprecated for some time now and have been deleted:

org.apache.http.client.params.ClientParamBean#setConnectionManagerFactory(org.apache.http.conn.ClientConnectionManagerFactory)
org.apache.http.client.protocol.ClientContextConfigurer#setAuthSchemePref(java.util.List)
org.apache.http.entity.mime.content.FileBody#writeTo(java.io.OutputStream, int)
org.apache.http.entity.mime.content.InputStreamBody#writeTo(java.io.OutputStream, int)
org.apache.http.entity.mime.content.StringBody#writeTo(java.io.OutputStream, int)

The following classes have been deprecated for some while now and have been deleted:

org.apache.http.impl.conn.tsccm.RefQueueHandler
org.apache.http.impl.conn.tsccm.AbstractConnPool no longer implements interface org.apache.http.impl.conn.tsccm.RefQueueHandler
org.apache.http.impl.conn.tsccm.ConnPoolByRoute no longer implements interface org.apache.http.impl.conn.tsccm.RefQueueHandler
org.apache.http.impl.conn.tsccm.RefQueueWorker



Release 4.2 BETA1
-------------------

This is the first BETA release of HttpClient 4.2. This release completes development of several
notable enhancements in HttpClient:

* New facade API for HttpClient based on the concept of a fluent interface. The fluent API exposes
  only the most fundamental functions of HttpClient and is intended for relatively simple use cases
  that do not require the full flexibility of HttpClient. However, the fluent API almost fully
  relieves the users from having to deal with connection management and resource deallocation.

* Redesigned and rewritten connection management code. As of release 4.2 HttpClient will be using
  pooling connection manager per default.

* Enhanced HTTP authentication API that enables HttpClient to handle more complex authentication
  scenarios. HttpClient 4.2 is now capable of making use of multiple authentication challenges
  and retry authentication with a fall-back scheme in case the primary one fails. This can be
  important for compatibility with Microsoft products that are often configured to use
  SPNEGO/Kerberos as the preferred authentication scheme.


Changelog
-------------------

* [HTTPCLIENT-1164] Compressed entities are not being cached properly.
  Contributed by Jon Moore <jonm at apache dot org>.

* [HTTPCLIENT-1154] MemcachedHttpCacheStorage should allow client to
  specify custom prefix string for keys.
  Contributed by Jon Moore <jonm at apache dot org>.

* [HTTPCLIENT-1153] MemcachedHttpCacheStorage uses URL as cache key;
  shouldn't due to fixed maximum-length memcached keys.
  Contributed by Jon Moore <jonm at apache dot org>.

* [HTTPCLIENT-1157] MemcachedHttpCacheStroage should throw IOExceptions
  instead of RuntimeExceptions.
  Contributed by James Miller <jamesmiller01 at gmail dot com>.

* [HTTPCLIENT-1152] MemcachedHttpCacheStorage should verify class of
  returned object before casting.
  Contributed by Rajika Kumarasiri <rajika at wso2 dot com>.

* [HTTPCLIENT-1155] CachingHttpClient fails to ensure that the response content gets fully consumed
  when using a ResponseHandler, which can potentially lead to connection leaks.
  Contributed by James Miller <jamesmiller01 at gmail dot com>

* [HTTPCLIENT-1147] When HttpClient-Cache cannot open cache file, should act like miss.
  Contributed by Joe Campbell <joseph.r.campbell at gmail.com>

* [HTTPCLIENT-1137] Values for the Via header are cached and reused by httpclient-cache.
  Contributed by Alin Vasile <alinachegalati at yahoo dot com>

* [HTTPCLIENT-1142] Infinite loop on NTLM authentication failure.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1143] CachingHttpClient leaks connections with stale-if-error.
  Contributed by James Miller <jamesmiller01 at gmail dot com>

Release 4.2 ALPHA1
-------------------

This is the first ALPHA release of HttpClient 4.2. The 4.2 branch enhances HttpClient in several
key areas and includes several notable features and improvements:

* New facade API for HttpClient based on the concept of a fluent interface. The fluent API exposes
  only the most fundamental functions of HttpClient and is intended for relatively simple use cases
  that do not require the full flexibility of HttpClient. However, the fluent API almost fully
  relieves the users from having to deal with connection management and resource deallocation.

* Redesigned and rewritten connection management code. As of release 4.2 HttpClient will be using
  pooling connection manager per default.

* Enhanced HTTP authentication API that enables HttpClient to handle more complex authentication
  scenarios. HttpClient 4.2 is now capable of making use of multiple authentication challenges
  and retry authentication with a fall-back scheme in case the primary one fails. This can be
  important for compatibility with Microsoft products that are often configured to use
  SPNEGO/Kerberos as the preferred authentication scheme.

Please note that new features included in this release are still considered experimental and
their API may change in the future ALPHA releases.

Changelog
-------------------

* [HTTPCLIENT-1128] SystemDefaultHttpClient (HttpClient implementation initialized using system
  properties).
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1135] RandomAccessFile mode 'w' used by HttpClientCache is not valid.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1131] HttpClient to authenticate preemptively using BASIC scheme if a userinfo
  attribute is specified in the request URI.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1134] make BasicResponseHandler consume response content in case of an unsuccessful
  result (status code >= 300).
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1132] ProxyClient implementation.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1127] fixed dead-lock between SingleClientConnManager and AbstractPooledConnAdapter.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1107] Auth framework redesign.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1116] ResponseCachingPolicy uses integers for sizes
  Contributed by Greg Bowyer <gbowyer at fastmail.co.uk >

* [HTTPCLIENT-1123] Support for pluggable DNS resolvers.
  Contributed by Alin Vasile <alinachegalati at yahoo dot com>

* [HTTPCLIENT-1120] DefaultHttpRequestRetryHandler#retryRequest should not retry aborted requests.
  Contributed by Alin Vasile <alinachegalati at yahoo dot com>

* Support for auth-int qop (quality of protection) option in Digest auth scheme.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1076] Fluent facade API (Google summer of code 2011 project).
  Contributed by Xu Lilu <cookieme at gmail.com>

* UriBuilder implementation.
  Contributed by Xu Lilu <cookieme at gmail.com>

* Redesign of connection management classes based on new pooling components from HttpCore.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1111] Added #prepareSocket method to SSLSocketFactory.
  Contributed by Pasi Eronen <pe at iki.fi>

* Added #reset() and #releaseConnection() methods to HttpRequestBase.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1105] AutoRetryHttpClient: built-in way to do auto-retry for certain status codes.
  Contributed by Dan Checkoway <dcheckoway at gmail.com>

* [HTTPCLIENT-1094] Digest auth scheme refactoring.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Lax implementation of RedirectStrategy.
  Contributed by Bartosz Firyn <songo.bercik at interia.pl>

* [HTTPCLIENT-1044] HttpRequestRetryHandler implementation compliant with the definition of
  idempotent methods given in the RFC 2616.
  Contributed by Oleg Kalnichevski <olegk at apache.org>


Release 4.1.2
-------------------

The HttpClient 4.1.2 is a bug fix release that addresses a number of non-critical issues reported
since release 4.1.1.

* [HTTPCLIENT-1100] Missing Content-Length header makes cached entry invalid
  Contributed by Bart Robeyns <bart dot robeyns at gmail dot com>

* [HTTPCLIENT-1098] Avoid expensive reverse DNS lookup on connect timeout exception.
  Contributed by Thomas Boettcher <tboett at gmail.com>

* [HTTPCLIENT-1097] BrowserCompatHostnameVerifier and StrictHostnameVerifier should handle
  wildcards in SSL certificates better.
  Contributed by Sebastian Bazley <sebb at apache.org>

* [HTTPCLIENT-1092] If ClientPNames.VIRTUAL_HOST does not provide the port, derive it from the
  current request.
  Contributed by Sebastian Bazley <sebb at apache.org>

* [HTTPCLIENT-1087] NTLM proxy authentication fails on retry if the underlying connection is closed
  as a result of a target authentication failure.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1079] Fixed Kerberos cross-realm support
  Contributed by Michael Osipov <1983-01-06 at gmx.net>

* [HTTPCLIENT-1078] Decompressing entities (DeflateDecompressingEntity, GzipDecompressingEntity)
  do not close content stream in #writeTo() method.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1075] Decompressing entities (DeflateDecompressingEntity, GzipDecompressingEntity)
  do not correctly handle content streaming.
  Contributed by James Abley <james.abley at gmail.com>

* [HTTPCLIENT-1051] Avoid reverse DNS lookups when opening SSL connections by IP address.
  Contributed by Oleg Kalnichevski <olegk at apache.org>


Release 4.1.1
-------------------

HttpClient v4.1.1 is a bug fix release that addresses a number of issues reported since
release 4.1, including one critical security issue (HTTPCLIENT-1061). All users of HttpClient 4.0.x
and 4.1 are strongly encouraged to upgrade.

* [HTTPCLIENT-1069] HttpHostConnectException not correctly retried for direct and non-tunnelled
  proxy connections.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1066] Changed the way URIUtils#rewriteURI handles multiple consecutive slashes in the
  URI path component: multiple leading slashes will be replaced by one slash in order to avoid
  confusion with the authority component. The remaining content of the path will not be modified.
  (also see HTTPCLIENT-929).
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1061] Fixed critical bug causing Proxy-Authorization header to be sent to the target
  host when tunneling requests through a proxy server that requires authentication.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1056] Fixed bug causing the RequestAuthCache protocol interceptor to generate
  an invalid AuthScope instance when looking up user credentials for preemptive authentication.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1053] Fixed the way DigestScheme generates nonce-count values.
  Contributed by Oleg Kalnichevski <olegk at apache.org>


Release 4.1
-------------------

The HttpClient 4.1 release builds upon the stable foundation laid by HttpClient 4.0 and adds several
functional improvements and popular features.

* Response caching conditionally compliant with HTTP/1.1 specification (full compliance with
  MUST requirements, partial compliance with SHOULD requirements)

* Full support for NTLMv1, NTLMv2, and NTLM2 Session authentication. The NTLM protocol code
  was kindly contributed by the Lucene Connector Framework project.

* Support for SPNEGO/Kerberos authentication.

* Persistence of authentication data between request executions within the same execution context.

* Support for preemptive authentication for BASIC and DIGEST schemes.

* Support for transparent content encoding. Please note transparent content encoding is not
  enabled per default in order to avoid conflicts with already existing custom content encoding
  solutions.

* Mechanism to bypass the standard certificate trust verification (useful when dealing with
  self-signed certificates).

* Simplified configuration for connection managers.

* Transparent support for host multihoming.

IMPORTANT: please note that the HttpClient 3.x branch is now officially END OF LIFE and is no longer
maintained and supported by the Apache HttpComponents project.

Changelog
-------------------
* The public API for the caching module had a minor change between 4.1-beta and 4.1-GA to the
  HttpCacheEntry class - the deprecated public Set<String> getVariantURIs() method and constructor
  public HttpCacheEntry(Date requestDate, Date responseDate,
            StatusLine statusLine, Header[] responseHeaders,
            Resource resource, Set<String> variants)
  were both removed.  This will not affect you unless you are implementing new storage backends
  that use the deprecated code and/or are implementing custom serializers for cache entries.

* Changed Browser-Compatibility and Best-Match cookie policies to emulate the behaviour of FireFox
  more closely when parsing Netscape style cookies. Comma will no longer be treated as a header
  element separator if Set-Cookie does not contain a Version attribute mandated by the
  RFC2109 / RFC 2965 cookie specifications.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1036] StringBody has incorrect default for characterset. (Default changed
  to US-ASCII)
  Contributed by Sebastian Bazley <sebb at apache.org>

* [HTTPCLIENT-975] Support stale-if-error and stale-while-revalidate extension directive (RFC5861).
  Contributed by Mohammed Azeem Uddin <mohammedazeem_uddin at comcast.com>,
  Michajlo Matijkiw <michajlo_matijkiw at comcast.com>, and
  Matthew Hawthorne <matthew_hawthorne at comcast.com>.

* [HTTPCLIENT-1033] HttpRoute.equals(Object o) is quite inefficient, as it does not take full
  advantage of shortcut logic.
  Contributed by Sebastian Bazley <sebb at apache.org>

* [HTTPCLIENT-1030] Implement "ignoreCookies" CookieSpec
  Contributed by Sebastian Bazley <sebb at apache.org>

Release 4.1 BETA1
-------------------

HttpClient 4.1 BETA1 finalizes the 4.1 API and brings a number of major improvements to the HTTP
caching module. This release also adds full support for NTLMv1, NTLMv2, and NTLM2 Session
authentication. The NTLM protocol code was kindly contributed by the Lucene Connector Framework
project.

Changelog
-------------------
* [HTTPCLIENT-1015] Support only-if-cached directive.
  Contributed by Michajlo Matijkiw <michajlo_matijkiw at comcast.com>

* [HTTPCLIENT-990] Allow heuristic freshness caching.
  Contributed by Michajlo Matijkiw <michajlo_matijkiw at comcast.com>

* [HTTPCLIENT-919] Support for NTLMv1, NTLMv2, and NTLM2 Session authentication.
  Contributed by Karl Wright <karl.wright at nokia.com>

* [HTTPCLIENT-1008] Send all variants' ETags on "variant miss".
  Contributed by Michajlo Matijkiw <michajlo_matijkiw at comcast.com> and
  Mohammed Azeem Uddin <mohammedazeem_uddin at comcast.com>

* [HTTPCLIENT-1011] Handling of IOExceptions thrown by cache components.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-1003] Handle conditional requests in cache.
  Contributed by Michajlo Matijkiw <michajlo_matijkiw at comcast.com> and
  Mohammed Azeem Uddin <mohammedazeem_uddin at comcast.com>

* [HTTPCLIENT-1002] Stale connection check fails if wire logging is on.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-1000] Maximum connection lifetimes settings for ThreadSafeClientConnManager.
  Contributed by Michajlo Matijkiw <michajlo_matijkiw at comcast.com>

* [HTTPCLIENT-960] HttpMultipart doesn't generate Content-Type header for binary parts in
  BROWSER_COMPATIBLE mode.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-998] Cache should use both Last-Modified and ETag for validations when available.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-997] Cache module should handle out-of-order validations properly and unconditionally
  refresh.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-994] Cache does not allow client to override origin-specified freshness using
  max-stale.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-995] Cache returns cached responses even if validators not consistent with all
  conditional headers.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-977] Memcached implementation for HttpCache.
  Contributed by Mohammed Azeem Uddin <mohammedazeem_uddin at comcast.com>

* [HTTPCLIENT-992] cache should not generate stale responses to requests explicitly requesting
  first-hand or fresh ones.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-991] cache module produces improperly formatted Warning header when revalidation
  fails.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-989] DefaultHttpRequestRetryHandler no longer retries non-idempotent http methods
  if NoHttpResponseException is thrown.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-988] Cache module should strip 'Content-Encoding: identity' from responses
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-987] cache module does not recognize equivalent URIs.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-986] cache module does not completely handle upstream Warning headers correctly
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-985] cache module should populate Via header to capture upstream and downstream protocols
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-984] Additional conditional compliance tests for the caching module for
  Content-Encoding, Content-Location, Date, Expires, Server, Transfer-Encoding, and Vary headers.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-978] HTTP cache update exception handling
  Contributed by Michajlo Matijkiw <michajlo_matijkiw at comcast.com>

* [HTTPCLIENT-981] CachingHttpClient returns a 411 respones when executing a POST (HttpPost)
  request.
  Contributed by Joe Campbell <joseph.r.campbell at gmail.com>

* [HTTPCLIENT-980] CachingHttpClient returns a 503 response when the backend HttpClient produces
  an IOException.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-978] Ehcache based HTTP cache implementation
  Contributed by Michajlo Matijkiw <michajlo_matijkiw at comcast.com>

* [HTTPCLIENT-967] support for non-shared (private) caches
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-969] BasicCookieStore#getCookies() to return a copy of Cookie list
  Contributed by David Smiley <dsmiley at mitre.org>

* [HTTPCLIENT-965] Fixed problem with cache not honoring must-revalidate or
  proxy-revalidate Cache-Control directives.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-964] 'no-cache' directives with field names are no longer transmitted
  downstream.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-963] Fixed handling of 'Cache-Control: no-store' on requests.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-962] Fixed handling of Authorization headers in shared cache mode.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-961] Not all applicable URIs are invalidated on PUT/POST/DELETEs
  that pass through client cache.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-958] Client cache no longer allows incomplete responses to be
  passed on to the client.
  Contributed by Jonathan Moore <jonathan_moore at comcast.com>

* [HTTPCLIENT-951] Non-repeatable entity enclosing requests are not correctly
  retried when 'expect-continue' handshake is active.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-948] In rare circumstances the idle connection handling code
  can leave closed connections in a inconsistent state.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-953] IllegalStateException thrown by RouteSpecificPool.
  Contributed by Guillaume <gueugaie at gmail.com>

* [HTTPCLIENT-952] Trust store parameter is ignored by SSLSocketFactory
  (affects version 4.1-alpha2 only)
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-937] CacheEntry made immutable; now uses immutable HttpEntity
  to store cached content.
  Contributed by David Mays <david_mays at comcast.com> and
  Oleg Kalnichevski <olegk at apache.org>

Release 4.1 ALPHA2
-------------------

HttpClient 4.1 ALPHA2 fixes a number of non-severe bugs discovered since
the last release and introduces support for two frequently requested features:

* HTTP/1.1 response caching

* transparent support for host multihoming

* a mechanism to bypass the standard certificate trust verification
(useful when dealing with self-signed certificates)

Compatibility notes
-------------------
(1) Please note the HTTP caching module is still considered experimental and
its API may change significantly in the future releases.

(2) This release eliminates Mime4J as a dependency for the HttpMime module.
HttpMime is no longer binary compatible with the previous releases.
Full API and binary compatibility between minor versions of HttpMime will be
maintained as of 4.1 GA release.

Changelog
-------------------

* [HTTPCLIENT-936] Fixed bug causing NPE or an infinite loop in
  the authentication code in case of a SPNEGO authentication failure.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-427] HTTP caching support
  Contributed by Joe Campbell, David Cleaver, David Mays, Jon Moore, Brad Spenla

* Dropped dependency on Mime4j for HttpMime.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Extended SSLSocketFactory with a mechanism to bypass the standard certificate
  trust verification (primarily to simplify dealing with self-signed
  certificates)
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-898] Improved support for host multihoming
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-916] UsernamePasswordCredentials, NTUserPrincipal,
  BasicClientCookie, BasicClientCookie2 and BasicCookieStore made Serializable.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-914] Upgraded Commons Codec dependency to version 1.4
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-903] Use ConcurrentHashMap instead of [Linked]HashMap for
  thread-safety. Improve performance of AuthSchemeRegistry, CookieSpecRegistry
  and SchemeRegistry classes.
  Contributed by Sebastian Bazley <sebb at apache.org>

* [HTTPCLIENT-902] HttpRequestRetryHandler not called on I/O exceptions
  thrown when opening a new connection.
  Contributed by Olivier Lamy <olamy at apache.org> and
  Oleg Kalnichevski <olegk at apache.org>

Release 4.1 ALPHA1
-------------------

HttpClient 4.1 ALPHA1 builds on the stable 4.0 release and adds several
functionality improvements and new features.

* Simplified configuration of connection managers.

* Persistence of authentication data between request executions within
  the same execution context.

* Support for SPNEGO/Kerberos authentication scheme

* Support for transparent content encoding. Please note transparent content
  encoding is not enabled per default in order to avoid conflicts with
  already existing custom content encoding solutions.

* 5 to 10% performance increase due to elimination of unnecessary Log object
  lookups by short-lived components.

Please note all methods and classes added in this release and marked as
4.1 are API unstable and can change in the future 4.1 ALPHA releases.

Changelog
-------------------

* [HTTPCLIENT-889] 'expect: continue' handshake disabled per default.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-862] Extended client's redirect handling interface to allow
  control of the content of the redirect.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-872] HttpClient can now persist authentication data between request
  executions as long as they share the same execution context. It has also become
  much easier to make HttpClient authenticate preemptively by pre-populating
  authentication data cache.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-883] SO_TIMEOUT is not reset on persistent (re-used) connections.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-832] Distinguish cookie format errors from violations of
  restrictions imposed by a cookie specification. In the latter case
  CookieRestrictionViolationException will be thrown.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-523] Support for SPNEGO authentication scheme.
  Contributed by Matthew Stevenson <mavricknzwork at yahoo.com>

* Simplified configuration of connection managers. Total connection maximum
  and maximum connection per route limits can be set using methods of
  the class instead of HTTP parameters.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Added parameters to define the order of preference for supported auth
  schemes for target host and proxy authentication.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-875] DefaultClientConnectionOperator#openConnection doesn't
  update the connection state if the connection socket changed after
  the call to SocketFactory#connectSocket().
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-834] Transparent content encoding support.
  Contributed by James Abley <james.abley at gmail.com>

Release 4.0.1
-------------------

This is a bug fix release that addresses a number of issues discovered since
the previous stable release. None of the fixed bugs is considered critical.
Most notably this release eliminates eliminates dependency on JCIP annotations.

This release is also expected to improve performance by 5 to 10% due to
elimination of unnecessary Log object lookups by short-lived components.

Changelog
-------------------

* [HTTPCLIENT-895] Eliminated Log lookups in short lived objects impairing
  performance.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-885] URLEncodedUtils now correctly parses form-url-encoded
  entities that specify a charset.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-884] UrlEncodedFormEntity now sets charset on the Content-Type
  header.
  Contributed by Jared Jacobs <jmjacobs at cs.stanford.edu>

* [HTTPCLIENT-883] SO_TIMEOUT is not reset on persistent (re-used) connections.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-882] Auth state is now correctly updated if a successful NTLM
  authentication results in a redirect. This is a minor bug as HttpClient
  manages to recover from the problem automatically.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-881] Fixed race condition in AbstractClientConnAdapter that makes
  it possible for an aborted connection to be returned to the pool.
  Contributed by Tim Boemker <tboemker at elynx.com> and
  Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-866] Removed dependency on jcip-annotations.jar.
  Contributed by Oleg Kalnichevski <olegk at apache.org>
  and Sebastian Bazley <sebb at apache.org>


Release 4.0
-------------------

HttpClient 4.0 represents a complete, ground-up redesign and almost a complete
rewrite of the HttpClient 3.x codeline. This release finally addresses several
design flaws that existed since the 1.0 release and could not be fixed without
a major code overhaul and breaking API compatibility.


Architectural changes
---------------------

* Redesign of the HttpClient internals addressing all known major
  architectural shortcomings of the 3.x codeline.

* Cleaner, more flexible and expressive API.

* More modular structure.

* Better performance and smaller memory footprint due to a more efficient HTTP
  transport based on HttpCore.

* Implementation of cross-cutting HTTP protocol aspects through protocol
  interceptors.

* Improved connection management, better handling of persistent connections,
  support for stateful connections

* Pluggable redirect and authentication handlers.

* Improved support for sending requests via a proxy or a chain of proxies

* More flexible SSL context customization

* Reduced intermediate garbage in the process of generating HTTP requests
  and parsing HTTP responses


Important notes
-------------------

* Future releases of HttpMime module may be binary incompatible with this
  release due to possible API changes in Apache Mime4J. Apache Mime4J is
  still being actively developed and its API is considered unstable.

* HttpClient 4.0 is not fully binary compatible with 4.0 BETA1 release.
  Some protected variables in connection management class have been
  made final in order to help ensure their thread safety:

    org.apache.http.conn.BasicEofSensorWatcher#attemptReuse
    org.apache.http.conn.BasicEofSensorWatcher#managedConn
    org.apache.http.impl.conn.DefaultClientConnectionOperator#schemeRegistry
    org.apache.http.impl.conn.DefaultHttpRoutePlanner#schemeRegistry
    org.apache.http.impl.conn.ProxySelectorRoutePlanner#schemeRegistry
    org.apache.http.impl.conn.SingleClientConnManager#alwaysShutDown
    org.apache.http.impl.conn.SingleClientConnManager#connOperator
    org.apache.http.impl.conn.SingleClientConnManager#schemeRegistry
    org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager#connOperator
    org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager#schemeRegistry


Bug fixes since 4.0 BETA2 release
-------------------

* [HTTPCLIENT-861] URIUtils#resolve is now compatible with all examples given
  in RFC 3986.
  Contributed by Johannes Koch <johannes.koch at fit.fraunhofer.de>

* [HTTPCLIENT-860] HttpClient no longer converts redirects of PUT/POST to GET
  for status codes 301, 302, 307, as required by the HTTP spec.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-859] CookieIdentityComparator now takes path attribute into
  consideration when comparing cookies.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* HttpClient will no longer send expired cookies back to the origin server.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-856] Proxy NTLM authentication no longer fails on a redirect to
  a different host.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-841] Removed automatic connection release using garbage collection
  due to a memory leak.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-853] Fixed bug causing invalid cookie origin port to be selected
  when the target is accessed on the default port and the connection is
  established via a proxy.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-852] Fixed bug causing automatically retried redirects fail with
  CircularRedirectException.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Fixed problem with the default HTTP response parser failing to handle garbage
  preceding a valid HTTP response.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* NonRepeatableRequestExceptions now include the cause that the original
  request failed.
  Contributed by Sam Berlin <sberlin at apache.org>

* [HTTPCLIENT-837] Fixed problem with the wire log skipping zero byte values
  if read one byte at a time.
  Contributed by Kirill Safonov <ksafonov at swiftteams.com>

* [HTTPCLIENT-823] 'http.conn-manager.max-total' parameter can be adjusted
  dynamically. However, the size of existing connection pools per route,
  once allocated, will not be adjusted.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-822] Default socket factories to rethrow SocketTimeoutException
  as ConnectTimeoutException in case of connect failure due to a time out.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-813] Fixed default port resolution. Invalid ports no longer
  get replaced with the default port value.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

Release 4.0 beta 2
-------------------

BETA2 is a maintenance release, which addresses a number of issues
discovered since the previous release.

The only significant new feature is an addition of an OSGi compliant
bundle combining HttpClient and HttpMime jars.

All upstream projects are strongly encouraged to upgrade.

* Fixed NPE in DefaultRequestDirector thrown when retrying a failed
  request over a proxied connection.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-803] Fixed bug in SSL host verifier implementations
  causing the SSL certificate to be rejected as invalid if the connection
  is established using an IP address.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-806] DefaultHttpMethodRetryHandler will no longer retry
  on ConnectExceptions.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* DigestScheme can use an arbitrary digest algorithm requested by the
  target server (such as SHA) as long as this algorithm is supported by
  the Java runtime.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Fixed parsing and validation of RFC2109 compliant Set-Cookie headers
  by the Best-Match cookie spec.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Fixed bug that can cause a managed connection to be returned from the
  pool in an inconsistent state.
  Contributed by Oleg Kalnichevski <olegk at apache.org>


4.0 Beta 1
-------------------

BETA1 release brings yet another round of API enhancements and
improvements in the area of connection management. Among the most notable
ones is the capability to handle stateful connections such as persistent
NTLM connections and private key authenticated SSL connections.

This is the first API stable release of HttpClient 4.0. All further
releases in the 4.0 code line will maintain API compatibility with this
release.

There has been a number of important bug fixes since ALPHA4. All upstream
projects are encouraged to upgrade to the latest release.

Please note HttpClient currently provides only limited support for NTLM
authentication. For details please see NTLM_SUPPORT.txt.

-------------------

Changelog:
-------------------

* [HTTPCLIENT-790] Protocol interceptors are now correctly invoked when
  executing CONNECT methods.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-668] Do not use static loggers.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-781] Respect Keep-Alive header's timeout value.
  Contributed by Sam Berlin <sberlin at apache.org>

* [HTTPCLIENT-779] Top-level classes (HttpClient, and HttpGet, HttpPut
  and similar HttpMethods) throw fewer checked exceptions.
  Contributed by Sam Berlin <sberlin at apache.org>

* HttpClient will throw an exception if an attempt is made to retry
  a request with a non-repeatable request entity.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Fixed request re-generation logic when retrying a failed request.
  Auto-generated headers will no accumulate.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-424] Preemptive authentication no longer limited to BASIC
  scheme only. HttpClient can be customized to authenticate preemptively
  with DIGEST scheme.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-670] Pluggable hostname resolver.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-719] Clone support for HTTP request and cookie objects.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-776] Fixed concurrency issues with AbstractPoolEntry.
  Contributed by Sam Berlin <sberlin at gmail.com>

* Resolved a long standing problem with HttpClient not taking into account
  the user context when pooling / re-using connections. HttpClient now
  correctly handles stateful / user specific connections such as persistent
  NTLM connections and SSL connections with client side authentication.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-773] Improved handling of the 'expires' attribute by the
  'Best Match' cookie spec.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Partial NTLM support (requires an external NTLM engine). For details see
  NTLM_SUPPORT.txt
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* Redesigned local execution context management.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

--------------------------------------

Release 4.0 Alpha 4
-------------------

ALPHA4 marks the completion of the overhaul of the connection management
code in HttpClient. All known shortcomings of the old HttpClient 3.x
connection management API have been addressed.

NTLM authentication remains the only missing major feature in the new
codeline that prevents us from moving awards the API freeze.

There has been a number of important bug fixes since ALPHA3. All upstream
projects are encouraged to upgrade to the latest release.

-------------------

HttpClient 3.x features that have NOT yet been ported:
-------------------

* NTLM authentication scheme

-------------------

Changelog:
-------------------

* [HTTPCLIENT-765] String.toLowerCase() / toUpperCase() should specify
  Locale.ENGLISH
  Contributed by Sebastian Bazley <sebb at apache.org>

* [HTTPCLIENT-769] Do not pool connection marked non-reusable.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-763] Fixed problem with AbstractClientConnAdapter#abortConnection()
  not releasing the connection if called from the main execution thread while
  there is no blocking I/O operation.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-652] Added optional state attribute to managed client connections.
  This enables connection managers to correctly handle stateful connections.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-673] Revised max connections per route configuration
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-753] Class Scheme and related classes moved to a separate package
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-757] Improved request wrapping in the DefaultClientRequestDirector.
  This also fixed the problem with the default proxy set at the client level
  having no effect.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-734] Request abort will unblock the thread waiting for a connection
  Contributed by Sam Berlin <sberlin at gmail.com>

* [HTTPCLIENT-759] Ensure release of connections back to the connection manager
  on exceptions.
  Contributed by Sam Berlin <sberlin at gmail.com>

* [HTTPCLIENT-758] Fixed the use of generics in AbstractHttpClient
  #removeRequestInterceptorByClass and #removeResponseInterceptorByClass
  Contributed by Johannes Koch <johannes.koch at fit.fraunhofer.de>

* [HTTPCLIENT-749] HttpParams beans
  Contributed by Stojce Dimski <sdmiski at yahoo.it>

* [HTTPCLIENT-755] Workaround for known bugs in java.net.URI.resolve()
  Bug ID: 4708535
  Contributed by Johannes Koch <johannes.koch at fit.fraunhofer.de>

--------------------------------------

Release 4.0 Alpha 3
-------------------

ALPHA3 release brings another round of API refinements and improvements in
functionality. As of this release HttpClient requires Java 5 compatible
runtime environment and takes full advantage of generics and new concurrency
primitives.

This release also introduces new default cookie policy that selects a cookie
specification depending on the format of cookies sent by the target host.
It is no longer necessary to know beforehand what kind of HTTP cookie support
the target host provides. HttpClient is now able to pick up either a lenient
or a strict cookie policy depending on the compliance level of the target host.

Another notable improvement is a completely reworked support for multipart
entities based on Apache mime4j library.

-------------------

HttpClient 3.x features that have NOT yet been ported:
-------------------

* NTLM authentication scheme

-------------------

Changelog:
-------------------

* [HTTPCLIENT-742] common interface for HttpRoute and RouteTracker
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-741] Fixed concurrency issues in AbstractClientConnAdapter.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-726] testcase for spurious wakeups in ThreadSafeClientConnManager
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-643] Automatic connect fail-over for multi-home remote servers.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-735] unsetting of DEFAULT_PROXY and FORCED_ROUTE in hierarchies
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-723] route planner based on java.net.ProxySelector
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-740] don't start connection GC thread in pool constructor
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-736] route planners use SchemeRegistry instead of ConnManager
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-730] Fixed rewriting of URIs containing escaped characters
  Contributed by Sam Berlin <sberlin at gmail.com> and
  Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-667] Added 'Meta' cookie policy that selects a cookie
  specification depending on the format of the cookie(s).
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-729] Move HttpRoute and related classes to routing package.
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-725] Use TimeUnit arguments for timeouts in connection manager.
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-677] Connection manager no longer uses Thread.interrupt().
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-716] Allow application-defined routes.
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-712] Improve HttpRoute API
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-711] Bad route computed for redirected requests
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-715] Remove RoutedRequest from API
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-705] Fixed incorrect handling of URIs with null path component.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-688] HttpOptions#getAllowedMethods can now handle multiple
  Allow headers.
  Contributed by Andrea Selva <selva.andre at gmail.com>

--------------------------------------

Release 4.0 Alpha 2
-------------------

ALPHA2 release is another milestone in the redesign of HttpClient. It includes
a number of improvements since ALPHA1, among which are improved connection
pooling, support for proxy chains, redesigned HTTP state and authentication
credentials management API, improved RFC 2965 cookie specification.

-------------------

HttpClient 3.x features that have NOT yet been ported
-------------------
* NTLM authentication scheme

* Support for multipart MIME coded entities

-------------------

Changelog
-------------------

* [HTTPCLIENT-698] Resolve non-absolute redirect URIs relative to
  the request URI
  Contributed by Johannes Koch <johannes.koch at fit.fraunhofer.de>

* [HTTPCLIENT-697] Throw a more intelligible exception when connection
  to a remote host cannot be established.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-689] Caching of SimpleDateFormat in DateUtils
  Contributed by Daniel Müller <strider at digitalstrider.com>

* [HTTPCLIENT-689] stackable parameters in AbstractHttpClient
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-477] Use distinct instances of the authentication handler
  interface for authentication with target and proxy hosts
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-690] ManagedClientConnection provides access to SSLSession
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-692] ClientConnectionManager throws InterruptedException
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCORE-116] moved parameter names to interfaces
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-649] support for proxy chains in HttpConn
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-636] refactor ThreadSafeClientConnManager in separate package
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-669] new HttpRoutePlanner interface and implementation
  Contributed by Andrea Selva <selva.andre at gmail.com>

* [HTTPCLIENT-653] detached connection wrapper no longer prevents
  garbage collection of ThreadSafeClientConnManager
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-674] use org.apache.http.util.VersionInfo instead of a local one
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-666] Replaced HttpState with CredentialsProvier and CookieStore interfaces
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCORE-100] revised HttpContext hierarchy
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-618] eliminate class HostConfiguration
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-672] re-sync with API changes in core alpha6-SNAPSHOT
  Contributed by Roland Weber <rolandw at apache.org>

--------------------------------------

Release 4.0 Alpha 1
-------------------

HttpClient 4.0 represents a complete, ground-up redesign and almost a complete
rewrite of the HttpClient 3.x codeline. This release finally addresses several
design flaws that existed since the 1.0 release and could not be fixed without
a major code overhaul and breaking API compatibility.

The HttpClient 4.0 API is still very experimental and is bound to change
during the course of the ALPHA development phase. Several important features
have not yet been ported to the new API.

Architectural changes
---------------------

* Redesign of the HttpClient internals addressing all known
  major architectural shortcomings of the 3.x codeline

* Cleaner, more flexible and expressive API

* Better performance and smaller memory footprint due to a more
  efficient HTTP transport based on HttpCore. HttpClient 4.0 is
  expected to be 10% to 25% faster than HttpClient 3.x codeline

* More modular structure

* Pluggable redirect and authentication handlers

* Support for protocol incerceptors

* Improved connection management

* Improved support for sending requests via a proxy or a chain of
  proxies

* Improved handling redirects of entity enclosing requests

* More flexible SSL context customization

* Reduced intermediate garbage in the process of
  generating HTTP requests and parsing HTTP responses

-------------------

HttpClient 3.x features that have NOT yet been ported
-------------------
* NTLM authentication scheme

* RFC2965 cookie policy (Cookie2)

* Support for multipart MIME coded entities

-------------------

Changelog
-------------------

The following is a list of contributions tracked in JIRA.
Note that this is not a complete list of contributions or changes.
Since the API was redesigned completely, tracking everything outside
of the source code repository would have been too burdensome.

* [HTTPCLIENT-655] User-Agent string no longer violates RFC
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-541] Virtual host API redesign
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-614] Allow for different strategies when checking
  CN of x509 certificates
  Contributed by Julius Davies <juliusdavies at gmail.com>

* [HTTPCLIENT-136] Fixed inadequate proxy support
  Long standing architectural problem. Issue opened on 19/Dec/2002.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-63] Support for pluggable redirect and authentication handlers
  Long standing architectural problem. Issue opened on 15/Jul/2002.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-245] Fixed redirect handling. HttpClient can now automatically
  handle redirects of entity enclosing requests.
  Long standing architectural problem. Issue opened on 14/Jul/2003.
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-613] HTTPS connections now verify CN of x509 certificates
  Contributed by Julius Davies <juliusdavies at gmail.com>

* [HTTPCLIENT-497] Wire/header logger names consistent with class loggers
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-484] AuthSSLProtocolSocketFactory in the main distribution
  Contributed by Oleg Kalnichevski <olegk at apache.org>

* [HTTPCLIENT-589] Do not consume the remaining response content if
  the connection is to be closed
  Contributed by Roland Weber <rolandw at apache.org>

* [HTTPCLIENT-475] Support for unconnected sockets. HTTP requests can now be
  aborted while network socket is still being connected.
  Contributed by Roland Weber <rolandw at apache.org>

