respondWithDefaultHeaders • Akka HTTP (original) (raw)

Signature

def respondWithDefaultHeaders(responseHeaders: HttpHeader*): Directive0
def respondWithDefaultHeaders(firstHeader: HttpHeader, otherHeaders: HttpHeader*): Directive0
def respondWithDefaultHeaders(responseHeaders: immutable.Seq[HttpHeader]): Directive0

Description

Adds the given HTTP headers to all responses coming back from its inner route only if a respective header with the same name doesn’t exist yet in the response.

This directive transforms HttpResponseHttpResponse and ChunkedResponseStart messages coming back from its inner route by potentially adding the given HttpHeaderHttpHeader instances to the headers list. A header is only added if there is no header instance with the same name (case insensitively) already present in the response.

See also respondWithDefaultHeader if you’d like to add only a single header.

Example

The respondWithDefaultHeaders directive is equivalent to the respondWithDefaultHeader directive which is shown in the example below, however it allows including multiple default headers at once in the directive, like so:

Scala

sourcerespondWithDefaultHeaders( Origin(HttpOrigin("http://akka.io")), RawHeader("X-Fish-Name", "Blippy")) { ??? }

Java

source`import static akka.http.javadsl.server.Directives.complete; import static akka.http.javadsl.server.Directives.respondWithDefaultHeaders;

final List headers = Arrays.asList( Origin.create(HttpOrigin.parse("http://akka.io")), RawHeader.create("X-Fish-Name", "Blippy")); respondWithDefaultHeaders(headers, () -> /.../ complete("Blip!"));`

The semantics remain the same however, as explained by the following example:

Scala

source`// custom headers val blippy = RawHeader("X-Fish-Name", "Blippy") val elTonno = RawHeader("X-Fish-Name", "El Tonno")

// format: OFF // by default always include the Blippy header, // unless a more specific X-Fish-Name is given by the inner route val route = respondWithDefaultHeader(blippy) { // blippy respondWithHeader(elTonno) { // / el tonno path("el-tonno") { // | / complete("¡Ay blippy!") // | |- el tonno } ~ // | | path("los-tonnos") { // | | complete("¡Ay ay blippy!") // | |- el tonno } // | | } ~ // | x complete("Blip!") // |- blippy } // x // format: ON

// tests: Get("/") ~> route ~> check { header("X-Fish-Name") shouldEqual Some(RawHeader("X-Fish-Name", "Blippy")) responseAs[String] shouldEqual "Blip!" }

Get("/el-tonno") ~> route ~> check { header("X-Fish-Name") shouldEqual Some(RawHeader("X-Fish-Name", "El Tonno")) responseAs[String] shouldEqual "¡Ay blippy!" }

Get("/los-tonnos") ~> route ~> check { header("X-Fish-Name") shouldEqual Some(RawHeader("X-Fish-Name", "El Tonno")) responseAs[String] shouldEqual "¡Ay ay blippy!" }`

Java

source`import static akka.http.javadsl.server.Directives.complete; import static akka.http.javadsl.server.Directives.path; import static akka.http.javadsl.server.Directives.respondWithDefaultHeaders; import static akka.http.javadsl.server.Directives.respondWithHeader;

//custom headers final RawHeader blippy = RawHeader.create("X-Fish-Name", "Blippy"); final HttpHeader akka = Origin.create(HttpOrigin.parse("http://akka.io")); final List defaultHeaders = Arrays.asList(blippy, akka); final RawHeader elTonno = RawHeader.create("X-Fish-Name", "El Tonno");

// format: OFF // by default always include the Blippy and Akka headers, // unless a more specific X-Fish-Name is given by the inner route final Route route = respondWithDefaultHeaders(defaultHeaders, () -> // blippy and akka respondWithHeader(elTonno, () -> // / el tonno path("el-tonno", () -> // | / complete("¡Ay blippy!") // | |- el tonno ).orElse( // | | path("los-tonnos", () -> // | | complete("¡Ay ay blippy!") // | |- el tonno ) // | | ) // | | ).orElse( // | x complete("Blip!") // |- blippy and akka ) // x ); //format: ON

testRoute(route).run(HttpRequest.GET("/")) .assertHeaderExists("X-Fish-Name", "Blippy") .assertHeaderExists("Origin", "http://akka.io") .assertEntity("Blip!");

testRoute(route).run(HttpRequest.GET("/el-tonno")) .assertHeaderExists("X-Fish-Name", "El Tonno") .assertEntity("¡Ay blippy!");

testRoute(route).run(HttpRequest.GET("/los-tonnos")) .assertHeaderExists("X-Fish-Name", "El Tonno") .assertEntity("¡Ay ay blippy!");`

See the respondWithDefaultHeader directive for an example with only one header.

Found an error in this documentation? The source code for this page can be found here. Please feel free to edit and contribute a pull request.