spring-framework/spring-webflux
Brian Clozel 4b732d62c2 Deprecate HttpHeaders.writableHttpHeaders
Prior to this commit, gh-21783 introduced `ReadOnlyHttpHeaders` to avoid
parsing media types multiple times during the lifetime of an HTTP
exchange: such values are cached and the headers map is made read-only.
This also added a new `HttpHeaders.writableHttpHeaders` method to unwrap
the read-only variant when needed.

It turns out this method sends the wrong signal to the community
because:
* the underlying map might be unmodifiable even if this is not an
  instance of ReadOnlyHttpHeaders
* developers were assuming that modifying the collection that backs the
  read-only instance would work around the cached values for
  Content-Type and Accept headers

This commit adds more documentation to highlight the desired behavior
for cached values by the read-only variant, and deprecates the
`writableHttpHeaders` method as `ReadOnlyHttpHeaders` is package private
and we should not surface that concept anyway.
Instead, this commit unwraps the read-only variant if needed when a new
HttpHeaders instance is created.

Closes gh-32116
2024-03-12 14:04:09 +01:00
..
src Deprecate HttpHeaders.writableHttpHeaders 2024-03-12 14:04:09 +01:00
spring-webflux.gradle Upgrade to Jetty 12 2023-09-04 14:03:29 +02:00