如何在 Spray 的嵌套路由中使用字符串指令提取器

Question

在这里回答我自己的问题，因为这花了我一天多的时间才弄清楚，这是一个非常简单的陷阱，我认为其他人可能运行。

在使用 spray 创建的 RESTful-esk 服务上工作时，我想匹配具有字母数字 ID 作为路径一部分的路由。这就是我最初的出发点：

case class APIPagination(val page: Option[Int], val perPage: Option[Int])
get {
  pathPrefix("v0" / "things") {
    pathEndOrSingleSlash {
      parameters('page ? 0, 'perPage ? 10).as(APIPagination) { pagination =>
        respondWithMediaType(`application/json`) {
          complete("things")
        }
      }
    } ~ 
    path(Segment) { thingStringId =>
      pathEnd {
        complete(thingStringId)
      } ~
      pathSuffix("subthings") {
        pathEndOrSingleSlash {
          complete("subthings")
        }
      } ~
      pathSuffix("othersubthings") {
        pathEndOrSingleSlash {
          complete("othersubthings")
        }
      } 
    }
  }
} ~ //more routes...

并且编译没有问题，但是当使用scalatest验证路由结构是否正确时，我很惊讶地发现这种输出：

"ThingServiceTests:"
"Thing Service Routes should not reject:"
- should /v0/things
- should /v0/things/thingId
- should /v0/things/thingId/subthings *** FAILED ***
  Request was not handled (RouteTest.scala:64)
- should /v0/things/thingId/othersubthings *** FAILED ***
  Request was not handled (RouteTest.scala:64)

我的路线有什么问题？

Answer 1

我看了很多资源，like this SO Question and this blog post but couldn't seem to find anything about using string Id's as a toplevel part of a route structure. I looked through the spray scaladoc as well as beat my head against the documentation on Path matchers for a while before spotting this important test (duplicated below):

"pathPrefix(Segment)" should {
    val test = testFor(pathPrefix(Segment) { echoCaptureAndUnmatchedPath })
    "accept [/abc]" in test("abc:")
    "accept [/abc/]" in test("abc:/")
    "accept [/abc/def]" in test("abc:/def")
    "reject [/]" in test()
  }

这让我想到了几件事。我应该尝试使用 pathPrefix 而不是 path。所以我将路线更改为如下所示：

get {
  pathPrefix("v0" / "things") {
    pathEndOrSingleSlash {
      parameters('page ? 0, 'perPage ? 10).as(APIPagination) { pagination =>
        respondWithMediaType(`application/json`) {
          listThings(pagination)
        }
      }
    } ~ 
    pathPrefix(Segment) { thingStringId =>
      pathEnd {
        showThing(thingStringId)
      } ~
      pathPrefix("subthings") {
        pathEndOrSingleSlash {
          listSubThingsForMasterThing(thingStringId)
        }
      } ~
      pathPrefix("othersubthings") {
        pathEndOrSingleSlash {
          listOtherSubThingsForMasterThing(thingStringId)
        }
      } 
    }
  }
} ~

并且很高兴我的所有测试都通过了并且路由结构正常工作。然后我将其更新为使用 Regex 匹配器：

pathPrefix(new scala.util.matching.Regex("[a-zA-Z0-9]*")) { thingStringId =>

并决定 post 对于遇到类似问题的任何其他人。正如 jrudolph 在评论中指出的那样，这是因为 Segment 期望匹配 <Segment><PathEnd> 而不是在路径中间使用。 pathPrefix 哪个对

更有用

如何在 Spray 的嵌套路由中使用字符串指令提取器

How to use string directive extractor in a nested route in Spray

scala

spray

spray-dsl