validate

Allows validating a precondition before handling a route.

Signature

def validate(check:

Description

Checks an arbitrary condition and passes control to the inner route if it returns true. Otherwise, rejects the request with a ValidationRejection containing the given error message.

Example

Scala
Java
sourceval route =
  extractUri { uri =>
    validate(uri.path.toString.size < 5, s"Path too long: '${uri.path.toString}'") {
      complete(s"Full URI: $uri")
    }
  }

// tests:
Get("/234") ~> route ~> check {
  responseAs[String] shouldEqual "Full URI: http://example.com/234"
}
Get("/abcdefghijkl") ~> route ~> check {
  rejection shouldEqual ValidationRejection("Path too long: '/abcdefghijkl'", None)
}
sourceimport static org.apache.pekko.http.javadsl.server.Directives.extractUri;
import static org.apache.pekko.http.javadsl.server.Directives.validate;

final Route route =
    extractUri(
        uri ->
            validate(
                () -> uri.path().length() < 5,
                "Path too long: " + uri.path(),
                () -> complete("Full URI: " + uri.toString())));

// tests:
testRoute(route).run(HttpRequest.GET("/234")).assertEntity("Full URI: http://example.com/234");
testRoute(route)
    .run(HttpRequest.GET("/abcdefghijkl"))
    .assertEntity("Path too long: /abcdefghijkl");
1.0.1