This commit makes the 3 existing InvocableHandlerMethod types more
consistent and comparable with each other.
1. Use of consistent method names and method order.
2. Consistent error formatting.
3. Explicit for loops for resolving argument values in webflux variant
because that makes it more readable, creates less garabage, and it's
the only way to bring consistency since the other two variants cannot
throw exceptions inside Optional lambdas (vs webflux variant which can
wrap it in a Mono).
4. Use package private HandlerMethodArgumentComposite in webflux
variant in order to pick up the resolver argument caching that the
other two variants have.
5. Polish tests.
6. Add missing tests for messaging variant.
This commit fixes a memory leak in ServerSentEventHttpMessageWriter
that occurs when the input stream contains an error. Test added as well.
Issue: SPR-17419
Review and update Servlet and Undertow adapters to release any data
buffers they be holding on to at the time of error or cancellation.
Also remove onDiscard hooks from Reactor and Undertow request body.
For Reactor we expect it to be handled. For Undertow there isn't
any Reactor Core upstream for the callback to be useful.
Issue: SPR-17410
This commit harmonizes the `HeadersAdapter` implementations across all
supported servers with regards to the `get(Object key)` contract; some
server implementations are not sticking to a `Map`-like contract and
return empty `List` instead of `null` when a header is not present.
This also fixes the `size()` implementations to reflect the number of
header keys, as some implementations consider multiple values for the
same header as different entries.
Issue: SPR-17396
This commit adds decoder/message-reader tests for errors in
the source data buffer publisher. Because the tests extend
AbstractDataBufferAllocatingTestCase, they also check whether
the buffers that precede the error in the stream are properly
released.
Issue: SPR-17025
Prior to this commit, an bug introduced in SPR-16949 prevented
`Mono.empty` bodies from being written to the response.
This commit ensures that empty bodies still trigger the writing to the
response and does not hang the processing of the exchange.
Issue: SPR-17220
Prior to this commit, when using the `SimpleClientHttpRequestFactory`
as a driver for `RestTemplate`, the HTTP response body would only be
drained if there was an attempt to read it in the first place.
This commit ensures that, even if there's no attempt at reading the
response body, it is properly drained when the response is closed to
make sure that the connection is released in a proper state and can be
put back in the connection pool for reuse.
Issue: SPR-17181
When dealing with `Optional` values in a Controller handler (for
example, values coming from a Spring Data repository), developers might
reuse this code snippet quite often:
```
@GetMapping("/user")
public ResponseEntity<Optional<User>> fetchUser() {
Optional<User> user = //...
return user.map(ResponseEntity::ok).orElse(notFound().build());
}
```
This commit adds a new static method on `ResponseEntity` for that,
simplifying the previous snippet with `return ResponseEntity.of(user);`
Note that in case more specific HTTP response headers are required by
the application, developers should use other static methods to
explicitly tell which headers should be used in each case.
Issue: SPR-17187
