SPR-11512 introduced support for annotation attribute aliases via
@AliasFor, requiring the explicit declaration of the 'attribute'
attribute. However, for aliases within an annotation, this explicit
declaration is unnecessary.
This commit improves the readability of alias pairs declared within an
annotation by introducing a 'value' attribute in @AliasFor that is an
alias for the existing 'attribute' attribute. This allows annotations
such as @ContextConfiguration from the spring-test module to declare
aliases as follows.
public @interface ContextConfiguration {
@AliasFor("locations")
String[] value() default {};
@AliasFor("value")
String[] locations() default {};
// ...
}
Issue: SPR-13289
Prior to this change, calling the `setDateHeader` method on a
Spring Test MockHttpServletResponse instance would just store the given
long value in a Map, not writing it as a formatted date String.
Also, calling `getDateHeader` on a MockHttpServletRequest would not
support date strings and could not parse those values.
This can be problematic when testing features related to date headers
such as "Expires", "If-Modified-Since", "Last-Modified", etc.
This commit adds formatting and parsing capabilities to Servlet Mocks
for date strings in HTTP headers.
When formatting dates to Strings, the date format used is the one
preferred by the HTTP RFC. When parsing date Strings, multiple date
formats are supported for better compatibility.
Issue: SPR-11912
Prior to this change, calling the `setDateHeader` method on a
MockHttpServletResponse instance (internal implementation for testing
the spring-web module) would just store the given long value in a Map,
not writing it as a formatted date String.
This can be problematic when testing features related to date headers
such as "Expires", "If-Modified-Since", "Last-Modified", etc.
This commit formats long dates into date Strings using the date format
recommended by the RFC and the GMT time zone.
When using an Apache Http components based infrastructure, a null header
value is handled as the empty string. The exact same infrastructure using
HttpURLConnection generates a header with no colon. This is actually not
proper HTTP and some components fail to read such request.
We now make sure to call HttpURLConnection#addRequestProperty with the
empty String for a null header value.
Issue: SPR-13225
Browsers like Chrome or Safari include an Origin header for same-origin
POST/PUT/DELETE requests, not only for cross-origin requests.
Before this commit, these same-origin requests would have been detected
as potential cross-origin requests, and rejected if the same-origin domain
is not part of the configured allowedOrigins.
This commit avoid to reject same-origin requests by reusing the logic
introduced in Spring 4.1 for detecting reliably Websocket/SockJS
same-origin requests with the WebUtils.isValidOrigin() method. This
logic has been extracted in a new WebUtils.isSameOrigin() method.
Issue: SPR-13206
This commit introduces the following changes:
- The new CorsConfigurationMapping class allows to share the mapped
CorsConfiguration logic between AbstractHandlerMapping and CorsFilter
- In AbstractHandlerMapping, the Map<String, CorsConfiguration>
corsConfiguration property has been renamed to corsConfigurations
- CorsFilter allows to process CORS requests at filter level, using any
CorsConfigurationSource implementation (for example
CorsConfigurationMapping)
Issue: SPR-13192
When using Appache Commons FileUpload, multi parts with binary data
(i.e. that are not actual files) are saved and then accessed as
String request parameters.
Before this change however the RequestPartServletServerHttpRequest
used a fixed encoding (UTF-8) while the parsing code in
CommonsFileUploadSupport/Resolver used the encoding from the
content-type header, or the request, or the FileUpload component.
This change does a best effort to determine the encoding of the
request parameter using a similar algorithm as the parsing side
that should work the same unless the encoding comes from the
FileUpload component which is not accessible.
Issue: SPR-13096
This split avoids a package tangle (between core and core.annotation) and also allows for selective use of raw annotation exposure versus synthesized annotations, with the latter primarily applicable to web and message handler processing at this point.
Issue: SPR-13153
Prior to this commit, `HttpEntityMethodProcessor` would rely on
`ServletWebRequest` to process conditional requests and with incoming
`"If-Modified-Since"` / `"If-None-Match"` request headers.
This approach is problematic since in that class:
* response is wrapped in a `ServletServerHttpResponse`
* this wrapped response does not write response headers right away
* `ServletWebRequest.checkNotModified` methods can't apply their
logic with incomplete response headers
This solution adds some minimal code duplication and applies
the conditional request logic within the Processor.
A possible alternative would be to improve the
`ServletServerHttpResponse$ServletResponseHttpHeaders` implementation
with write methods - but this solution would only work for Servlet 3.x
applications.
Issue: SPR-13090
This commit introduces the following changes:
- In AbstractMessageConverterMethodProcessor, the type aware variant of
canWrite() is now called when the converter implements
GenericHttpMessageConverter.
- The Javadoc has been updated in GenericHttpMessageConverter to make it clear
that the type aware canRead() and canWrite() methods should perform the same
checks than non type aware ones.
- AbstractGenericHttpMessageConverter now implements default type aware
canRead() and canWrite() methods than just call the non type aware variants.
Due to this, if subclasses just override the non type aware variants,
they still have the right behavior.
Issue: SPR-13161
Prior to this commit, Spring's MimeType checked for equality between
two MIME types based on the equality of their properties maps; however,
the properties maps contain string representations of the "charset"
values. Thus, "UTF-8" is never equal to "utf-8" which breaks the
contract for character set names which must be compared in a
case-insensitive manner.
This commit addresses this issue by ensuring that "charset" properties
in MimeType instances are compared as Java Charset instances, thereby
ignoring case when checking for equality between charset names.
Issue: SPR-13157
This commit adds canWrite() and write() methods to the
GenericHttpMessageConverter interface. These are type aware variants
of the methods available in HttpMessageConverter, in order to keep
parametrized type information when serializing objects.
AbstractMessageConverterMethodProcessor now calls those type aware
methods when the message converter implements GenericHttpMessageConverter.
AbstractJackson2HttpMessageConverter and GsonHttpMessageConverter uses
these new methods to make @ResponseBody method return type available
for type resolution instead of just letting the JSON serializer trying
to guess the type to use from the object to serialize.
Issue: SPR-12811
- Simplified "check" algorithms in CorsConfiguration
- Improved robustness of setter methods in CorsConfiguration in order to
avoid attempts to modify immutable lists
- Improved CORS documentation and fixed typo
- Introduced constants in CorsConfiguration
- Removed auto-boxing in CorsRegistration
Before this change HandlerMethodReturnValueHandler's were invoked in a
specific order (type-based, annotation-based, custom). However handlers
that deal with asynchronous return value handling need to always be
considered first. This affects custom handlers in particular since they
are normally ordered last.
This change introduces an AsyncHandlerMethodReturnValueHandler
sub-interface with a single method to determine if the return value is
asynchronous and if it is to look for a matching handler only among
those that are of type AsyncHandlerMethodReturnValueHandler.
Issue: SPR-13083
Before this change a missing path variable value resulted in a 400
error where in fact the error is due to a mismatch between the
declared @PathVariable and the URI template, i.e. a 500 error.
This change introduced a MissingPathVariableException as a sub-class
of ServletRequestBindingException (the exception previously thrown)
and results in a response status code of 500 by default.
Issue: SPR-13121
Prior to this change, the `"Last-Modified"` and "`Etag`" support had
been improved with SPR-11324: HTTP response headers are now
automatically added for conditional requests and more.
This commit fixes the format of the "`Last-Modified`" and "`ETag`"
values, which were using an epoch timestamp rather than an HTTP-date
format defined in RFC 7231 section 7.1.1.1.
Also, Conditional responses are only applied when the given response
applies, i.e. when it has an compatible HTTP status (2xx).
Issue: SPR-13090
This commit introduces support for RFC 7239: Forwarded HTTP Extension in
the UriComponentsBuilder. Unfortunately, RFC 7239 is not a complete
replacement for the X-Forwarded-* headers: specifically, there is not
direct replacement for X-Forwarded-Port. The JIRA contains more
information.
Issue: SPR-11856
This commit introduces first-class support for aliases for annotation
attributes. Specifically, this commit introduces a new @AliasFor
annotation that can be used to declare a pair of aliased attributes
within a single annotation or an alias from an attribute in a custom
composed annotation to an attribute in a meta-annotation.
To support @AliasFor within annotation instances, AnnotationUtils has
been overhauled to "synthesize" any annotations returned by "get" and
"find" searches. A SynthesizedAnnotation is an annotation that is
wrapped in a JDK dynamic proxy which provides run-time support for
@AliasFor semantics. SynthesizedAnnotationInvocationHandler is the
actual handler behind the proxy.
In addition, the contract for @AliasFor is fully validated, and an
AnnotationConfigurationException is thrown in case invalid
configuration is detected.
For example, @ContextConfiguration from the spring-test module is now
declared as follows:
public @interface ContextConfiguration {
@AliasFor(attribute = "locations")
String[] value() default {};
@AliasFor(attribute = "value")
String[] locations() default {};
// ...
}
The following annotations and their related support classes have been
modified to use @AliasFor.
- @ManagedResource
- @ContextConfiguration
- @ActiveProfiles
- @TestExecutionListeners
- @TestPropertySource
- @Sql
- @ControllerAdvice
- @RequestMapping
Similarly, support for AnnotationAttributes has been reworked to
support @AliasFor as well. This allows for fine-grained control over
exactly which attributes are overridden within an annotation hierarchy.
In fact, it is now possible to declare an alias for the 'value'
attribute of a meta-annotation.
For example, given the revised declaration of @ContextConfiguration
above, one can now develop a composed annotation with a custom
attribute override as follows.
@ContextConfiguration
public @interface MyTestConfig {
@AliasFor(
annotation = ContextConfiguration.class,
attribute = "locations"
)
String[] xmlFiles();
// ...
}
Consequently, the following are functionally equivalent.
- @MyTestConfig(xmlFiles = "test.xml")
- @ContextConfiguration("test.xml")
- @ContextConfiguration(locations = "test.xml").
Issue: SPR-11512, SPR-11513
`BeanWrapperImpl` and `DirectFieldAccessor` are two
`ConfigurablePropertyAccessor` implementations with different features
set.
This commit harmonizes the two implementations to use a common base class
that delegates the actual property handling to the sub-classes:
* `BeanWrapperImpl`: `PropertyDescriptor` and introspection utilities
* `DirectFieldAccessor`: reflection on `java.lang.Field`
Issues: SPR-12206 - SPR-12805
This commit introduces support for OkHttp
(http://square.github.io/okhttp/) as a backing implementation for
ClientHttpRequestFactory and AsyncClientHttpRequestFactory.
Issue: SPR-12893
After this change CorsProcessor has a single processRequest method and
it also explicitly deals with a null CorsConfiguration, which for
pre-flight requests results in a rejection while for simple requests
results in no CORS headers added.
The AbstractHandlerMapping now uses a LinkedHashMap to preserve the
order in which global patterns are provided.
This commit adds JavaConfig based global CORS configuration
capabilities to Spring MVC. It is now possible to specify
multiple CORS configurations, each mapped on a path pattern,
by overriding
WebMvcConfigurerAdapter#configureCrossOrigin(CrossOriginConfigurer).
It is also possible to combine global and @CrossOrigin based
CORS configuration.
Issue: SPR-12933
This change introduces a strategy for expanding a URI template into a
URI and makes it a property of the RestTemplate and AsyncRestTemplate
so that they can be pre-configured with such a strategy.
The DefaultUriTemplateHandler relies on UriComponentsBuilder internally
and provides functionality equivalent to using the UriTemplate.
A DefaultUriTemplateHandler can also be configured to parse the path
of a URI template into path segments in order to allow expanding URI
variables according to path segment encoding rules.
Issue: SPR-12750
Before this change AbstractHandlerMethodMapping used a map from Method
to CorsConfiguration. That works for regular @RequestMapping methods.
However frameworks like Spring Boot and Spring Integration may
programmatically register the same Method under multiple mappings,
i.e. adapter/gateway type classes.
This change ensures that CorsConfiguraiton is indexed by HandlerMethod
so that we can store CorsConfiguration for different handler instances
even when the method is the same.
In order for to make this work, HandlerMethod now provides an
additional field called resolvedFromHandlerMethod that returns the
original HandlerMethod (with the String bean name). This makes it
possible to perform reliable lookups.
Issue: SPR-11541
CorsConfiguration now provides methods to check and determine the
allowed origin, method, and headers according to its own configuration.
This simplifies significantly the work that needs to be done from
DefaultCorsProcessor. However an alternative CorsProcessor can still
access the raw CorsConfiguration and perform its own checks.
Issue: SPR-12885
This commit adds CORS related headers to HttpHeaders
and update DefaultCorsProcessor implementation to
use ServerHttpRequest and ServerHttpResponse instead
of HttpServletRequest and HttpServletResponse. Usage
of ServerHttpResponse allows to avoid using Servlet 3.0
specific methods in order keep CORS support Servlet 2.5
compliant.
Issue: SPR-12885
The onFailure callback and future.get() occur in different threads so
this change adds a latch to ensure we have both before asserting.
Issue: SPR-12887
AbstractHttpMessageConverter now tries to call getDefaultContentType
with the actual value to be converted to see if that will result in
a more concrete mediat type than application/octet-stream.
Issue: SPR-12894
This commit introduces support for CORS in Spring Framework.
Cross-origin resource sharing (CORS) is a mechanism that allows
many resources (e.g. fonts, JavaScript, etc.) on a web page to
be requested from another domain outside the domain from which
the resource originated. It is defined by the CORS W3C
recommandation (http://www.w3.org/TR/cors/).
A new annotation @CrossOrigin allows to enable CORS support
on Controller type or method level. By default all origins
("*") are allowed.
@RestController
public class SampleController {
@CrossOrigin
@RequestMapping("/foo")
public String foo() {
// ...
}
}
Various @CrossOrigin attributes allow to customize the CORS configuration.
@RestController
public class SampleController {
@CrossOrigin(origin = { "http://site1.com", "http://site2.com" },
allowedHeaders = { "header1", "header2" },
exposedHeaders = { "header1", "header2" },
method = RequestMethod.DELETE,
maxAge = 123, allowCredentials = "true")
@RequestMapping(value = "/foo", method = { RequestMethod.GET, RequestMethod.POST} )
public String foo() {
// ...
}
}
A CorsConfigurationSource interface can be implemented by HTTP request
handlers that want to support CORS by providing a CorsConfiguration
that will be detected at AbstractHandlerMapping level. See for
example ResourceHttpRequestHandler that implements this interface.
Global CORS configuration should be supported through ControllerAdvice
(with type level @CrossOrigin annotated class or class implementing
CorsConfigurationSource), or with XML namespace and JavaConfig
configuration, but this is not implemented yet.
Issue: SPR-9278
This commit adds a filters property to MappingJacksonValue
and also manages a special FilterProvider class name model key in
order to be able to specify a customized FilterProvider for each
handler method execution, and thus provides a more dynamic
alternative to our existing JsonView support.
A filters property is also now available in Jackson2ObjectMapperBuilder
and Jackson2ObjectMapperFactoryBean in order to set easily a
global FilterProvider.
More details about @JsonFilter at
http://wiki.fasterxml.com/JacksonFeatureJsonFilter.
Issue: SPR-12586
This commit introduces support for "Path Segment URI Variable
expansion", see https://tools.ietf.org/html/rfc6570#section-3.2.6.
In practice, this means that URI template variables prefixed with a '/'
are treated like path segments and - as such - will encode any '/'
found. For example: {/foo} expanded with "bar/baz" with result in
"bar%2F".
Issue: SPR-12750
This reverts commit a57d42829c after the
realization of a weaknesses with the proposed approach.
For example if a path segment contains both a /-prefixed and a regular
URI variable, there is no way to split that into a sequence of path
and path segments. The solution will have to be on the side of
UriComponents at the time of encoding.
Prior to this commit, Cache-Control HTTP headers could be set using
a WebContentInterceptor and configured cache mappings.
This commit adds support for cache-related HTTP headers at the controller
method level, by returning a ResponseEntity instance:
ResponseEntity.status(HttpStatus.OK)
.cacheControl(CacheControl.maxAge(1, TimeUnit.HOURS).cachePublic())
.eTag("deadb33f8badf00d")
.body(entity);
Also, this change now automatically checks the "ETag" and
"Last-Modified" headers in ResponseEntity, in order to respond HTTP
"304 - Not Modified" if necessary.
Issue: SPR-8550
This commit improves HTTP caching defaults and flexibility in
Spring MVC.
1) Better default caching headers
The `WebContentGenerator` abstract class has been updated with
better HTTP defaults for HTTP caching, in line with current
browsers and proxies implementation (wide support of HTTP1.1, etc);
depending on the `setCacheSeconds` value:
* sends "Cache-Control: max-age=xxx" for caching responses and
do not send a "must-revalidate" value by default.
* sends "Cache-Control: no-store" or "Cache-Control: no-cache"
in order to prevent caching
Other methods used to set specific header such as
`setUseExpiresHeader` or `setAlwaysMustRevalidate` are now deprecated
in favor of `setCacheControl` for better flexibility.
Using one of the deprecated methods re-enables previous HTTP caching
behavior.
This change is applied in many Handlers, since
`WebContentGenerator` is extended by `AbstractController`,
`WebContentInterceptor`, `ResourceHttpRequestHandler` and others.
2) New CacheControl builder class
This new class brings more flexibility and allows developers
to set custom HTTP caching headers.
Several strategies are provided:
* `CacheControl.maxAge(int)` for caching responses with a
"Cache-Control: max-age=xxx" header
* `CacheControl.noStore()` prevents responses from being cached
with a "Cache-Control: no-store" header
* `CacheControl.noCache()` forces caches to revalidate the cached
response before reusing it, with a "Cache-Control: no-store" header.
From that point, it is possible to chain method calls to craft a
custom CacheControl instance:
```
CacheControl cc = CacheControl.maxAge(1, TimeUnit.HOURS)
.cachePublic().noTransform();
```
3) Configuring HTTP caching in Resource Handlers
On top of the existing ways of configuring caching mechanisms,
it is now possible to use a custom `CacheControl` to serve
resources:
```
@Configuration
public class MyWebConfig extends WebMvcConfigurerAdapter {
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
CacheControl cc = CacheControl.maxAge(1, TimeUnit.HOURS);
registry.addResourceHandler("/resources/**)
.addResourceLocations("classpath:/resources/")
.setCacheControl(cc);
}
}
```
or
```
<mvc:resources mapping="/resources/**" location="classpath:/resources/">
<mvc:cachecontrol max-age="3600" cache-public="true"/>
</mvc:resources>
```
Issue: SPR-2779, SPR-6834, SPR-7129, SPR-9543, SPR-10464
This change improves the following use cases with
`WebRequest.checkNotModified(String etag)` and
`WebRequest.checkNotModified(long lastModifiedTimeStamp)`:
1) Allow weak comparisons for ETags
Per rfc7232 section-2.3, ETags can be strong or weak;
this change allows comparing weak forms `W/"etagvalue"` but does
not make a difference between strong and weak comparisons.
2) Allow multiple ETags in client requests
HTTP clients can send multiple ETags values in a single header such as:
`If-None-Match: "firstvalue", "secondvalue"`
This change makes sure each value is compared to the one provided by
the application side.
3) Extended support for ETag values
This change adds padding `"` to the ETag value provided by
the application, if not already done:
`etagvalue` => `"etagvalue"`
It also supports wildcard values `*` that can be sent by HTTP clients.
4) Sending validation headers for 304 responses
As defined in https://tools.ietf.org/html/rfc7232#section-4.1
`304 Not Modified` reponses must generate `Etag` and `Last-Modified`
HTTP headers, as they would have for a `200 OK` response.
5) Providing a new method to validate both Etag & Last-Modified
Also, this change adds a new method
`WebRequest.checkNotModified(String etag, long lastModifiedTimeStamp)`
in order to support validation of both `If-None-Match` and
`Last-Modified` headers sent by HTTP clients, if both values are
supported by the application code.
Even though this approach is recommended by the HTTP rfc (setting both
Etag and Last-Modified headers in the response), this requires more
application logic and may not apply to all resources produced by the
application.
Issue: SPR-11324
This commit introduces support for HTTP byte ranges in the
ResourceHttpRequestHandler. This support consists of a number of
changes:
- Parsing of HTTP Range headers in HttpHeaders, using a new HttpRange
class and inner ByteRange/SuffixByteRange subclasses.
- MIME boundary generation moved from FormHttpMessageConverter to
MimeTypeUtils.
- writePartialContent() method introduced in ResourceHttpRequestHandler,
handling the byte range logic
- Additional partial content tests added to
ResourceHttpRequestHandlerTests.
Issue: SPR-10805
After this change UriComponentsBuilder#uriComponents method no longer
no longer copies from the given UriComponents but rather lets the
UriComponents instance copy itself to the UriComponentsBuilder.
This avoids the need for instanceof checks and also makes it possible
to distinguish between path and path segments, which otherwise is
internal knowledge of UriComponentsBuilder.
Issue: SPR-12742
Revised HandlerMethod.getBeanType() impl for both web and messaging.
In addition, HandlerMethods get created with the internal BeanFactory now.
Issue: SPR-12832
Prior to this commit, the ContentCachingRequestWrapper would immediately
consume the wrapped request's InputStream when asked for the cached
content; that caused several issues:
* the request body was read in memory even if it wasn't yet consumed by
the application, leading to inefficiencies.
* when requesting the InputStream, an empty InputStream was returned
since the original was already read.
This case only happened for form POSTs requests.
This commit makes sure that the wrapper does not alter the request
expected behavior:
* when getting the inputstream, it is wrapped in order to cache its
content
* when getting request parameters, the request body is cached and its
inputstream is consumed, as expected
Issue: SPR-12810
All HttpMessageConverters should support StreamingHttpOutputMessage.
Specifically, the BufferedImageHttpMessageConverter and
FormHttpMessageConverter should do so.
Issue: SPR-12715
With this commit, WebUtils.isValidOrigin() logs an error message instead
of throwing an IllegalArgumentException when Origin header value is
invalid (for example when it does not contain the scheme).
Issue: SPR-12697
This commit adds support for a same origin check that compares
Origin header to Host header. It also changes the default setting
from all origins allowed to only same origin allowed.
Issues: SPR-12697, SPR-12685
Before this change, detection of X-Forwarded-* headers was only built
into ServletUriComponentsBuilder.
This change adds a new method for creating a UriComponentsBuilder from
an existing HttpRequest. This is equivalent to the fromUri method +
X-Forwarded-* header values.
This commit also adds a modules(Module...) method in addition to
modules(List<Module> modules) in order to be consistent with other
parts of the API.
Issue: SPR-12634
Before this change, the maxRequestSize property was used (incorrectly)
to limit both the size of the request and response. The change:
- removes maxRequestSize and therefore no longer places limits on the
size of the request thus matching to AbstractBufferingClientHttpRequest
which is the base class for other buffering client implementations.
- adds maxResponseSize property required to create Netty's
HttpObjectAggregator for aggregating responses.
Issue: SPR-12623
This commit adds ResponseBodyEmitter and SseEmitter (and also
ResponseEntity<ResponseBodyEmitter> and ResponseEntity<SseEmitter>) as
new return value types supported on @RequestMapping controller methods.
See Javadoc on respective types for more details.
Issue: SPR-12212
Prior to this commit, the `ContentCachingRequestWrapper` class would
cache the response content only if the reponse would be consumed using
its InputStream. In case of a Form request, Spring MVC consumes the
response using the `getParameter*` Servlet API methods. This causes the
cached content to never be written.
This commit makes the `ContentCachingResponseWrapper` write the request
body to the cache buffer by using the `getParameter*` API, thus avoiding
those issues.
Issue: SPR-7913
Modules (well-known or user provided) registration is now performed
first in order to allow their configuration to be customized by more
specific ones like custom serializers or deserializers.
Issue: SPR-12634
Prior to this commit, HTTP responses without body (response status 204
or 304, Content-Length: 0) were handled properly by RestTemplates. But
some other cases were not properly managed, throwing exceptions for
valid HTTP responses.
This commit better handles HTTP responses, using a response wrapper that
can tell if a response:
* has no message body (HTTP status 1XX, 204, 304 or Content-Length:0)
* has an empty message body
This covers rfc7230 Section 3.3.3.
Issue: SPR-8016
Prior to this change, the ShallowEtagHeaderFilter would use a
ResizableByteArrayOutputStream to internally write data and calculate
the ETag. While that implementation is faster than the regular
ByteArrayOutputStream (since it has a better strategy for growing the
internal buffer), a lot of buffer copying/writing still happens.
This change adds a new FastByteArrayOutputStream implementation that
internally uses a LinkedList<Byte[]> to store the content. So when
writing bytes to that OutputStream implementation, new byte[] are
added to the list when the previous ones are full. This saves most
of the instantiating/copying operations.
Note that new methods were added in DigestUtils to allow usage of
Streams instead of byte[], which is more efficient in our case.
Fixes#653
Issue: SPR-12081
Update HttpComponents wrapper to merge local customizations with the
default of the current HttpClient instead of overriding everything.
This is available as from HttpComponents 4.4. that exposes the default
request config from the client via the Configurable interface. If the
client does not implement such interface, the previous behaviour is
applied
Issue: SPR-12583
Sam Brannen
Juergen Hoeller
Brian Clozel
Sebastien Deleuze
Stephane Nicoll
Rossen Stoyanchev
izeye
Arjen Poutsma
Luciano Leggieri
Markus Malkusch
Radosław Józwik
Juergen Hoeller
Craig Andrews