optionalHeaderValue

Description

Traverses the list of request headers with the specified function and extracts the first value the function returns as Optional[value].

The optionalHeaderValue directive is similar to the headerValue directive but always extracts an Option value instead of rejecting the request if no matching header could be found.

Example

TODO: Example snippets for JavaDSL are subject to community contributions! Help us complete the docs, read more about it here: write example snippets for Akka HTTP Java DSL #20466.