path

Signature

def path[L](pm: PathMatcher[L]): Directive[L]

Description

Matches the complete unmatched path of the RequestContextRequestContext against the given PathMatcher, potentially extracts one or more values (depending on the type of the argument).

This directive filters incoming requests based on the part of their URI that hasn’t been matched yet by other potentially existing pathPrefix directives on higher levels of the routing structure. Its one parameter is usually an expression evaluating to a PathMatcher instance (see also: The PathMatcher DSL).

As opposed to the rawPathPrefix or rawPathPrefixTest directives path automatically adds a leading slash to its PathMatcher argument, you therefore don’t have to start your matching expression with an explicit slash.

The path directive attempts to match the complete remaining path, not just a prefix. If you only want to match a path prefix and then delegate further filtering to a lower level in your routing structure use the pathPrefix directive instead. As a consequence it doesn’t make sense to nest a path or pathPrefix directive underneath another path directive, as there is no way that they will ever match (since the unmatched path underneath a path directive will always be empty). For a comparison between path directives check Overview of path directives.

Depending on the type of its PathMatcher argument the path directive extracts zero or more values from the URI. If the match fails the request is rejected with an empty rejection set.

Note

The empty string (also called empty word or identity) is a neutral element of string concatenation operation, so it will match everything, but remember that path requires whole remaining path being matched, so (/) will succeed and (/whatever) will fail. The pathPrefix provides more liberal behaviour.

Example

Scala
val route =
  concat(
    path("foo") {
      complete("/foo")
    },
    path("foo" / "bar") {
      complete("/foo/bar")
    },
    pathPrefix("ball") {
      concat(
        pathEnd {
          complete("/ball")
        },
        path(IntNumber) { int =>
          complete(if (int % 2 == 0) "even ball" else "odd ball")
        }
      )
    }
  )

// tests:
Get("/") ~> route ~> check {
  handled shouldEqual false
}

Get("/foo") ~> route ~> check {
  responseAs[String] shouldEqual "/foo"
}

Get("/foo/bar") ~> route ~> check {
  responseAs[String] shouldEqual "/foo/bar"
}

Get("/ball/1337") ~> route ~> check {
  responseAs[String] shouldEqual "odd ball"
}
Java
import static akka.http.javadsl.server.Directives.path;

// matches /foo/
path(segment("foo").slash(), () -> complete(StatusCodes.OK));

// matches /foo/bar
path(segment("foo").slash(segment("boo")), () -> complete(StatusCodes.OK));

// NOTE: matches /foo%2Fbar and doesn't match /foo/bar
path(segment("foo/bar"), () -> complete(StatusCodes.OK));

// NOTE: matches /foo/bar
path(separateOnSlashes("foo/bar"), () -> complete(StatusCodes.OK));

// matches e.g. /foo/123 and extracts "123" as a String
path(segment("foo").slash(segment(compile("\\d+"))), (value) ->
    complete(StatusCodes.OK));

// matches e.g. /foo/bar123 and extracts "123" as a String
path(segment("foo").slash(segment(compile("bar(\\d+)"))), (value) ->
    complete(StatusCodes.OK));

// similar to `path(Segments)`
path(neutral().repeat(0, 10), () -> complete(StatusCodes.OK));

// identical to path("foo" ~ (PathEnd | Slash))
path(segment("foo").orElse(slash()), () -> complete(StatusCodes.OK));
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