As announced in "the state of HTTP clients in Spring" blog post
(https://spring.io/blog/2025/09/30/the-state-of-http-clients-in-spring),
the deprecation timeline for `RestTemplate` was announced last November
and docs were updated accordingly.
This commit `@Deprecate` `RestTemplate` and related types for removal to
send a stronger signal to our community.
The actual removal is scheduled for Spring Framework 8.0 (not yet
scheduled).
Closes gh-36574
Prior to this commit, the `SockJsClient` would use the
`RestTemplateXhrTransport`. `RestClient` is a modern replacement for
RestTemplate and should be used instead.
This commit introduces the `RestClientXhrTransport` variant as an
immediate replacement.
Closes gh-36566
Although this commit also changes the visibility of some test methods
to package-private, the remainder of that task will be addressed in
conjunction with gh-36496.
Closes gh-36495
Prior to this commit, the `StandardWebSocketUpgradeStrategy` would get
the HTTP headers from the handshake request and store them in the
WebSocket session for the entire duration of the session.
As of gh-36334, Spring MVC manages HTTP directly with a native API
instead of copying them. This improves performance but also uncovered
this bug: we cannot keep a reference to HTTP headers once the HTTP
exchange is finished, because such resources can be recycled and reused.
This commit ensures that the handshake headers are copied into the
session info to keep them around for the entire duration of the session.
Without that, Tomcat will raise an `IllegalStateException` at runtime.
This was already done for WebFlux in SPR-17250, but the latest header
management changes in Framework uncovered this issue for the Standard
WebSocket container case.
Fixes gh-36486
Prior to this commit (and despite the changes made in commit
4593f877dd), WebSocketHttpHeaders was not compatible with the
HttpHeaders(HttpHeaders) constructor or the copyOf(HttpHeaders) and
readOnlyHttpHeaders(HttpHeaders) factory methods.
To address that, this commit revises the implementation of
WebSocketHttpHeaders so that it only extends HttpHeaders, analogous to
ReadOnlyHttpHeaders. In other words, WebSocketHttpHeaders no longer
stores or delegates to a local HttpHeaders instance.
Closes gh-35792
Since HttpHeaders no longer implements MultiValueMap (see gh-33913),
a few interoperability issues have arisen between HttpHeaders and
WebSocketHttpHeaders.
To address those issues, this commit:
- Revises addAll(HttpHeaders), putAll(HttpHeaders), and putAll(Map) in
HttpHeaders so that they no longer operate on the HttpHeaders.headers
field.
- Overrides addAll(String, List), asSingleValueMap(), and
asMultiValueMap() in WebSocketHttpHeaders.
- Deletes putAll(HttpHeaders), putAll(Map), and forEach(BiConsumer) in
WebSocketHttpHeaders, since they do not need to be overridden.
This commit also removes unnecessarily overridden Javadoc in
WebSocketHttpHeaders and revises the implementation of several methods
in HttpHeaders so that they delegate to key methods such as get()
instead of directly accessing the HttpHeaders.headers field.
See gh-33913
Closes gh-35792
This commit updates Jackson 3 JSON support to use JsonMapper
instead of ObjectMapper in converters, codecs and view constructors.
As a consequence, AbstractJacksonDecoder, AbstractJacksonEncoder,
AbstractJacksonHttpMessageConverter and JacksonCodecSupport are
now parameterized with <T extends ObjectMapper>.
Closes gh-35282
Undertow does not support Servlet 6.1, we need to remove compatibility
tests as well as Undertow-specific classes for WebSocket and reactive
support.
Closes gh-35354
Sam Brannen
rstoyanchev
Yanming Zhou
Kai Zander
Brian Clozel
Juergen Hoeller
Manu Sridharan
Sébastien Deleuze
KNU-K
Jeroen Meijer