Question

首先，我对Akka没有经验，所以我自己调试这个很糟糕。我尝试了here中的示例，并且发布消息有效（这意味着凭据有效），但是没有消息被发出。服务帐户被授予所有权限。

我的代码看起来像这样，基本上与示例中的完全相同：

def coordinator_students(request):
    FSJ_user = get_FSJ_user(request.user.username)
    student_list = Student.objects.all().order_by('ccid')
    filtered_list = StudentFilter(request.GET, queryset=student_list)

    student_paginator = Paginator(filtered_list.qs, 25)

    template = loader.get_template("FSJ/coord_student_list.html")
    context = get_standard_context(FSJ_user)
    context["student_list"] = student_list

    page = request.GET.get('page', 1)

    try:
        students = student_paginator.page(page)
    except PageNotAnInteger:
        students = student_paginator.page(1)
    except EmptyPage:
        students = student_paginator.page(student_paginator.num_pages)

    context["filter"] = filtered_list
    context["students"] = students
    return HttpResponse(template.render(context, request))

我发现package com.example.google.pubsub import java.io.FileInputStream import java.security.spec.PKCS8EncodedKeySpec import java.security.{KeyFactory, PrivateKey} import java.util.Base64 import akka.actor.ActorSystem import akka.stream.{ActorMaterializer, Attributes, Outlet, SourceShape} import akka.stream.alpakka.googlecloud.pubsub.scaladsl.GooglePubSub import akka.stream.alpakka.googlecloud.pubsub._ import akka.stream.scaladsl.{Sink, Source} import akka.stream.stage.{GraphStage, GraphStageLogic} import akka.{Done, NotUsed} import com.google.api.client.googleapis.auth.oauth2.GoogleCredential import scala.concurrent.duration._ import scala.concurrent.Future object SubscriberMain extends App { println("#### SUBSCRIBER ####") val privateKey: PrivateKey = { import java.io.FileInputStream val credential = GoogleCredential.fromStream(new FileInputStream("mycredentials.json")) val privateKey = credential.getServiceAccountPrivateKey privateKey } val clientEmail = "main-19@weirdproject.iam.gserviceaccount.com" val projectId = "weirdproject" val apiKey = "xxxx" val subscription = "somesubscription" implicit val system = ActorSystem() implicit val mat = ActorMaterializer() val subscriptionSource: Source[ReceivedMessage, NotUsed] = GooglePubSub.subscribe(projectId, apiKey, clientEmail, privateKey, subscription) val ackSink: Sink[AcknowledgeRequest, Future[Done]] = GooglePubSub.acknowledge(projectId, apiKey, clientEmail, privateKey, subscription) subscriptionSource .map { message => val data = message.message.data println(s"received a message: $data") message.ackId } .groupedWithin(1000, 1.minute) .map(AcknowledgeRequest.apply) .to(ackSink) }永远不会被执行，这似乎是没有提取任何消息的原因。

Answer 1

您拥有的是流的定义，但您没有运行它。致电run()：

subscriptionSource
  .map { message =>
    val data = message.message.data
    println(s"received a message: $data")
    message.ackId
  }
  .groupedWithin(1000, 1.minute)
  .map(AcknowledgeRequest.apply)
  .to(ackSink)
  .run() // <---

或者，使用runWith()，这是一种方便的方法，可以返回Sink的具体化值：

val result: Future[Done] =
  subscriptionSource
    .map { message =>
      val data = message.message.data
      println(s"received a message: $data")
      message.ackId
    }
    .groupedWithin(1000, 1.minute)
    .map(AcknowledgeRequest.apply)
    .runWith(ackSink)

有关定义和运行流的更多信息，请here。

Google Pub / Sub Subscriber不接收消息

1 个答案: