如何崩溃 Spray 指令

How to collapse of Spray Directives

如何尽可能地折叠这些指令?

我能够将三个指令折叠到 mainHeader 中,但是如何同时包含 authenticate 和 responseWithMediaType?

val mainHeaders = cors & headerValueByName("Access_Token") & headerValueByName("Tenant_Name")

override def getLayer = path("api" / Segment / "model" / "layers") { modeledSystemName =>
    mainHeaders { (accessToken, tenantName) =>
      authenticate(validate(accessToken)) { authInfo =>
        respondWithMediaType(`application/json`) {
          get {
            onComplete(service.getlayers(modeledSystemName, tenantName)) {
              case Success(layers) => complete(layers)
              //case Success(None) => complete(NotFound, "Release version not found")
              case Failure(ex) => complete(InternalServerError, s"An error occurred: ${ex.getMessage}")
            }
          }
        }
      }
    }
  }

喷雾路线超级可组合,所以你可以做任何你想做的事。例如我会这样写这条路线:

val authWithHeader = headerValueByName("Access_Token")
  .flatMap(accessToken => authenticate(validate(accessToken)))

val authenticatedJsonRoute = cors &
  authWithHeader &
  headerValueByName("Tenant_Name") &
  respondWithMediaType(MediaTypes.`application/json`)

override val getLayer =
  (get & path("api" / Segment / "model" / "layers")) { modeledSystemName =>
    authenticatedJsonRoute { (authInfo, tenantName) =>
      onComplete(service.getlayers(modeledSystemName, tenantName)) {
        case Success(layers) => complete(layers)
        //case Success(None) => complete(NotFound, "Release version not found")
        case Failure(ex) => complete(InternalServerError, s"An error occurred: ${ex.getMessage}")
      }
    }
  }

让我解释一下这段代码。首先,我创建了读取 header 值的指令 authWithHeader,然后使用该值进行身份验证。它超级简单,所有魔法都由 flatMap 完成。

然后,我创建了 authenticatedJsonRoute,它只是其他简单指令的组合。组合魔术是通过 & 运算符完成的(在这种情况下我将其发音为 "and then")并且这些指令将按顺序执行。

最后,我在完整的路由 getLayer.

中使用了我的组合指令 authenticatedJsonRoute