Request values
A request value of type RequestVal<T> is a typed structure that represents some aspect of the request that can be interpreted as a value of type T. A RequestVal instance abstracts the knowledge about how to extract a certain value from the request and interpret it as a T. It is used in combination with Handlers.
The advantage of representing a request detail as a RequestVal instead of performing ad-hoc analysis of a request are:
- you can define an "inventory" of HTTP primitives for your application that you can reuse in many places of your application
- automatic handling of errors when an expected value was not found in a request or if it could not be interpreted as the expected Java type
Note, that the Scala version of the routing DSL has no direct correspondent to RequestVals. Instead, a Scala-side Directive can have "extractions" that are reflected in the type of the Directive.
Predefined Request values
akka-http provides a set of predefined request values for request data commonly accessed in a web service.
These request values are defined in the following objects:
- akka.http.javadsl.server.values.FormFields
- Contains request values for basic data like URI components, request method, peer address, or the entity data.
- akka.http.javadsl.server.values.FormFieldsCookies
- Contains request values representing cookies.
- akka.http.javadsl.server.values.FormFields
- Contains request values to access form fields unmarshalled to various primitive Java types.
- akka.http.javadsl.server.values.Headers
- Contains request values to access request headers or header values.
- akka.http.javadsl.server.values.FormFieldsHttpBasicAuthenticator
- An abstract class to implement to create a request value representing a HTTP basic authenticated principal.
- akka.http.javadsl.server.values.FormFieldsParameters
- Contains request values to access URI paramaters unmarshalled to various primitive Java types.
- akka.http.javadsl.server.values.FormFieldsPathMatchers
- Contains request values to match and access URI path segments.
- akka.http.javadsl.server.values.FormFieldsCustomRequestVal
- An abstract class to implement arbitrary custom request values.
- akka.http.javadsl.server.values.HttpBasicAuthenticator.scala
- An abstract class to implement HTTP basic authentication
- akka.http.javadsl.server.values.OAuth2Authenticator
- An abstract class to implement Oauth 2 bearer token authentication
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