encodeResponseWith

Signature

def encodeResponseWith(first: Encoder, more: Encoder*): Directive0

Description

Encodes the response with the encoding that is requested by the client via the Accept-Encoding if it is among the provided encoders or rejects the request with an UnacceptedResponseEncodingRejection(supportedEncodings).

The response encoding is determined by the rules specified in RFC7231.

If the Accept-Encoding header is missing then the response is encoded using the first encoder.

If the Accept-Encoding header is empty and NoCoding is part of the encoders then no response encoding is used. Otherwise the request is rejected.

Example

Scala
val route = encodeResponseWith(Coders.Gzip) { complete("content") }

// tests:
Get("/") ~> route ~> check {
  response should haveContentEncoding(gzip)
}
Get("/") ~> `Accept-Encoding`(gzip, deflate) ~> route ~> check {
  response should haveContentEncoding(gzip)
}
Get("/") ~> `Accept-Encoding`(deflate) ~> route ~> check {
  rejection shouldEqual UnacceptedResponseEncodingRejection(gzip)
}
Get("/") ~> `Accept-Encoding`(identity) ~> route ~> check {
  rejection shouldEqual UnacceptedResponseEncodingRejection(gzip)
}

// with custom compression level:
val routeWithLevel9 = encodeResponseWith(Coders.Gzip(compressionLevel = 9)) { complete("content") }
Get("/") ~> routeWithLevel9 ~> check {
  response should haveContentEncoding(gzip)
}
Java
import static akka.http.javadsl.server.Directives.complete;
import static akka.http.javadsl.server.Directives.encodeResponseWith;

final Route route = encodeResponseWith(
  Collections.singletonList(Coder.Gzip),
  () -> complete("content")
);

// tests:
testRoute(route).run(HttpRequest.GET("/"))
  .assertHeaderExists(ContentEncoding.create(HttpEncodings.GZIP));

testRoute(route).run(
  HttpRequest.GET("/")
    .addHeader(AcceptEncoding.create(HttpEncodings.GZIP))
    .addHeader(AcceptEncoding.create(HttpEncodings.DEFLATE))
).assertHeaderExists(ContentEncoding.create(HttpEncodings.GZIP));

runRouteUnSealed(route,
  HttpRequest.GET("/")
    .addHeader(AcceptEncoding.create(HttpEncodings.DEFLATE))
).assertRejections(Rejections.unacceptedResponseEncoding(HttpEncodings.GZIP));

runRouteUnSealed(route,
  HttpRequest.GET("/")
    .addHeader(AcceptEncoding.create(HttpEncodings.IDENTITY))
).assertRejections(Rejections.unacceptedResponseEncoding(HttpEncodings.GZIP));

final Route routeWithLevel9 = encodeResponseWith(
        Collections.singletonList(Coder.GzipLevel9),
        () -> complete("content")
);

testRoute(routeWithLevel9).run(HttpRequest.GET("/"))
  .assertHeaderExists(ContentEncoding.create(HttpEncodings.GZIP));
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