respondWithDefaultHeaders
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 HttpResponse
HttpResponse
and ChunkedResponseStart
messages coming back from its inner route by potentially adding the given HttpHeader
HttpHeader
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
-
source
respondWithDefaultHeaders( Origin(HttpOrigin("http://pekko.apache.org")), RawHeader("X-Fish-Name", "Blippy")) { ??? }
- Java
-
source
import static org.apache.pekko.http.javadsl.server.Directives.complete; import static org.apache.pekko.http.javadsl.server.Directives.respondWithDefaultHeaders; final List<HttpHeader> headers = Arrays.asList( Origin.create(HttpOrigin.parse("http://pekko.apache.org")), 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 org.apache.pekko.http.javadsl.server.Directives.complete; import static org.apache.pekko.http.javadsl.server.Directives.path; import static org.apache.pekko.http.javadsl.server.Directives.respondWithDefaultHeaders; import static org.apache.pekko.http.javadsl.server.Directives.respondWithHeader; // custom headers final RawHeader blippy = RawHeader.create("X-Fish-Name", "Blippy"); final HttpHeader pekko = Origin.create(HttpOrigin.parse("http://pekko.apache.org")); final List<HttpHeader> defaultHeaders = Arrays.asList(blippy, pekko); final RawHeader elTonno = RawHeader.create("X-Fish-Name", "El Tonno"); // format: OFF // by default always include the Blippy and Pekko 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://pekko.apache.org") .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.