+htp #19756: Add extractData and extractRequestEntity directives. (#20730)

* 19756: Add extractData and extractRequestEntity directives.

remove unnecessary import

* #19756: add documentation to extractDataBytes and extractRequestEntity directives

akka-docs/rst/scala/code/docs/http/scaladsl/server/directives/BasicDirectivesExamplesSpec.scala

@@ -795,5 +795,36 @@ class BasicDirectivesExamplesSpec extends RoutingSpec {
     }
     //#
   }
+  "extractRequestEntity-example" in {
+    //#extractRequestEntity-example
+    val route =
+      extractRequestEntity { entity =>
+        complete(s"Request entity content-type is ${entity.contentType}")
+      }
+
+    // tests:
+    val httpEntity = HttpEntity(ContentTypes.`text/plain(UTF-8)`, "req")
+    Post("/abc", httpEntity) ~> route ~> check {
+      responseAs[String] shouldEqual s"Request entity content-type is text/plain; charset=UTF-8"
+    }
+    //#
+  }
+  "extractDataBytes-example" in {
+    //#extractDataBytes-example
+    val route =
+      extractDataBytes { data ⇒
+        val sum = data.runFold(0) { (acc, i) ⇒ acc + i.utf8String.toInt }
+        onSuccess(sum) { s ⇒
+          complete(HttpResponse(entity = HttpEntity(s.toString)))
+        }
+      }
+
+    // tests:
+    val dataBytes = Source.fromIterator(() ⇒ Iterator.range(1, 10).map(x ⇒ ByteString(x.toString)))
+    Post("/abc", HttpEntity(ContentTypes.`text/plain(UTF-8)`, data = dataBytes)) ~> route ~> check {
+      responseAs[String] shouldEqual "45"
+    }
+    //#
+  }
 
 }