在启动Play应用程序期间没有插入数据(使用Play 2.4和reactivemongo 11.11)

Question

我们在MongoDB2.6中使用Play Framework2.4。但是，由于我们将reactivemongo从0.11.10迁移到了0.11.11-play24，有些地方出了问题。

在应用程序开始时，我们将一些数据加载到mongodb中。一切看起来都很好，应用程序已经启动，日志中没有出现错误，但是没有在数据库中插入数据。

下面是在Global.scala中启动应用程序的代码：

override def onStart(app: Application) {
   Logger.info("creating object in database...")
   someProducts.foreach{ product =>
     ProductDB.insertOrUpdate(product._id, product)
   }
}

为了注入reactivemongo，我们决定暂时不使用@Inject()，因此我们使用current.injector (根据Reactivemongo文件)。注:我们完全删除了ReactiveMongoPlugin的每一个痕迹，因为它在play-reactivemongo 0.11.11-play24中被废弃了。

这里我们定义了我们的模型并注入了ReactiveMongo：

abstract class MongoDB[T: Format, ID: Format] {
   def collection: JSONCollection

   def insertOrUpdate( _id: ID, o: T) = collection.update(Json.obj("_id" -> _id), o, upsert = true)
}

object ProductDB extends MongoDB[Product, String] {
  override def collection = current.injector.instanceOf[ReactiveMongoApi].db.collection("products")
}

在application.conf中，使用以下行启用了ReactiveMongoModule：play.modules.enabled += "play.modules.reactivemongo.ReactiveMongoModule"

应用程序日志：

[debug] p.a.l.c.ActorSystemProvider - Starting application default Akka system: application
[info] application - starting application, build at: 2016-05-17T13:00:18+0200
[info] application - creating object in database...
[info] application - ReactiveMongoApi starting...
[info] application - ReactiveMongoApi successfully configured with DB 'application'! Servers:
[localhost:27017]
[info] play.api.Play - Application started (Dev)

以下是mongodb的日志：

2016-05-17T13:00:27.774+0200 [initandlisten] connection accepted from 127.0.0.1:65478 #3 (1 connection now open)
2016-05-17T13:00:27.833+0200 [conn3] run command admin.$cmd { ismaster: 1 }
2016-05-17T13:00:27.833+0200 [conn3] command admin.$cmd command: isMaster { ismaster: 1 } ntoreturn:1 keyUpdates:0 numYields:0  reslen:178 0ms
2016-05-17T13:00:27.880+0200 [initandlisten] connection accepted from 127.0.0.1:65479 #4 (2 connections now open)
2016-05-17T13:00:27.880+0200 [initandlisten] connection accepted from 127.0.0.1:65480 #5 (3 connections now open)
2016-05-17T13:00:27.880+0200 [initandlisten] connection accepted from 127.0.0.1:65481 #6 (4 connections now open)
2016-05-17T13:00:27.880+0200 [initandlisten] connection accepted from 127.0.0.1:65482 #7 (5 connections now open)
2016-05-17T13:00:27.880+0200 [initandlisten] connection accepted from 127.0.0.1:65483 #8 (6 connections now open)
2016-05-17T13:00:27.881+0200 [initandlisten] connection accepted from 127.0.0.1:65484 #9 (7 connections now open)
2016-05-17T13:00:27.881+0200 [initandlisten] connection accepted from 127.0.0.1:65485 #10 (8 connections now open)
2016-05-17T13:00:27.881+0200 [initandlisten] connection accepted from 127.0.0.1:65486 #11 (9 connections now open)
2016-05-17T13:00:27.882+0200 [initandlisten] connection accepted from 127.0.0.1:65487 #12 (10 connections now open)
2016-05-17T13:00:27.888+0200 [conn3] run command admin.$cmd { ismaster: 1 }
2016-05-17T13:00:27.888+0200 [conn3] command admin.$cmd command: isMaster { ismaster: 1 } ntoreturn:1 keyUpdates:0 numYields:0  reslen:178 0ms
2016-05-17T13:00:27.888+0200 [conn3] run command admin.$cmd { ismaster: 1 }
2016-05-17T13:00:27.889+0200 [conn3] command admin.$cmd command: isMaster { ismaster: 1 } ntoreturn:1 keyUpdates:0 numYields:0  reslen:178 0ms
2016-05-17T13:00:27.889+0200 [conn3] run command admin.$cmd { ismaster: 1 }
2016-05-17T13:00:27.889+0200 [conn3] command admin.$cmd command: isMaster { ismaster: 1 } ntoreturn:1 keyUpdates:0 numYields:0  reslen:178 0ms
2016-05-17T13:00:27.889+0200 [conn3] run command admin.$cmd { ismaster: 1 }
2016-05-17T13:00:27.889+0200 [conn3] command admin.$cmd command: isMaster { ismaster: 1 } ntoreturn:1 keyUpdates:0 numYields:0  reslen:178 0ms
2016-05-17T13:00:27.889+0200 [conn3] run command admin.$cmd { ismaster: 1 }
2016-05-17T13:00:27.889+0200 [conn3] command admin.$cmd command: isMaster { ismaster: 1 } ntoreturn:1 keyUpdates:0 numYields:0  reslen:178 0ms
2016-05-17T13:00:27.890+0200 [conn3] run command admin.$cmd { ismaster: 1 }
2016-05-17T13:00:27.890+0200 [conn3] command admin.$cmd command: isMaster { ismaster: 1 } ntoreturn:1 keyUpdates:0 numYields:0  reslen:178 0ms
2016-05-17T13:00:27.890+0200 [conn3] run command admin.$cmd { ismaster: 1 }
2016-05-17T13:00:27.890+0200 [conn3] command admin.$cmd command: isMaster { ismaster: 1 } ntoreturn:1 keyUpdates:0 numYields:0  reslen:178 0ms
2016-05-17T13:00:27.891+0200 [conn3] run command admin.$cmd { ismaster: 1 }
2016-05-17T13:00:27.891+0200 [conn3] command admin.$cmd command: isMaster { ismaster: 1 } ntoreturn:1 keyUpdates:0 numYields:0  reslen:178 0ms
2016-05-17T13:00:27.891+0200 [conn3] run command admin.$cmd { ismaster: 1 }
2016-05-17T13:00:27.891+0200 [conn3] command admin.$cmd command: isMaster { ismaster: 1 } ntoreturn:1 keyUpdates:0 numYields:0  reslen:178 0ms

Answer 1

您需要在加载数据库之后插入：

    def db: DefaultDB = Await.result(reactiveMongoApi.database, Duration.Inf)

问题是，现在，reactiveMongoApi.db是同步的，如果直接使用，连接还没有完成(生命周期)。

因此，我建议您要么等待数据库(如上面的代码)，要么将回调注册到缓冲区中，该缓冲区将在数据库初始化后执行。

    reactiveMongoApi.database.onSuccess {
      case _ => callbacks.foreach(_())
    }