Directives

A directive is a wrapper for a route or a list of alternative routes that adds one or more of the following functionality to its nested route(s):

• it filters the request and lets only matching requests pass (e.g. the get directive lets only GET-requests pass)
• it modifies the request or the RequestContext (e.g. the path directives filters on the unmatched path and then passes an updated RequestContext unmatched path)
• it modifies the response coming out of the nested route

akka-http provides a set of predefined directives for various tasks. You can access them by either extending from akka.http.javadsl.server.AllDirectives or by importing them statically with import static akka.http.javadsl.server.Directives.*;.

These classes of directives are currently defined:

BasicDirectives

Contains methods to create routes that complete with a static values or allow specifying Handlers to process a request.

CacheConditionDirectives

Contains a single directive conditional that wraps its inner route with support for Conditional Requests as defined by RFC 7234.

CodingDirectives

Contains directives to decode compressed requests and encode responses.

CookieDirectives

Contains a single directive setCookie to aid adding a cookie to a response.

ExecutionDirectives

Contains directives to deal with exceptions that occurred during routing.

FileAndResourceDirectives

Contains directives to serve resources from files on the file system or from the classpath.

HostDirectives

Contains directives to filter on the Host header of the incoming request.

MethodDirectives

Contains directives to filter on the HTTP method of the incoming request.

MiscDirectives

Contains directives that validate a request by user-defined logic.

PathDirectives

Contains directives to match and filter on the URI path of the incoming request.

RangeDirectives

Contains a single directive withRangeSupport that adds support for retrieving partial responses.

SchemeDirectives

Contains a single directive scheme to filter requests based on the URI scheme (http vs. https).

WebSocketDirectives

Contains directives to support answering WebSocket requests.

TODO this page should be rewritten as the corresponding Scala page