无法使用Scala驱动程序将数据插入mongo

我无法使用Scala驱动程序将数据保存到Mongo中

简而言之，代码已完成，但是数据从未插入Mongo。创建并订阅了观察者，但是什么也没有发生。

这是我的代码的副本

object MongoTest {
  def main(args: Array[String]) {
  val SERVER = "127.0.0.1"
  val DATABASE="mytest"
  val connection = MongoClient("mongodb://"+SERVER)
  val database = connection.getDatabase(DATABASE)

  var items:List[Document] = List[Document]()
  for(i <- 1 to 10){
    items = items:+ Document("_id"->new ObjectId(),"val"->i)//generate dummy data
  }

  val latch = new CountDownLatch(1)
  val db  =  database.getCollection("testInsert")
  db.insertMany(items).subscribe(new Observer[Completed] {

     override def onError(e: Throwable): Unit = {
        println("Error")
        e.printStackTrace()
     }

     override def onSubscribe(subscription: Subscription): Unit = {
       println("Exporting")
     }

     override def onComplete(): Unit = {
       println("Completed")
       connection.close()
       latch.countDown()
     }

     override def onNext(result: Completed): Unit = {
        println("Next")
     }

    })
    latch.await()
 }
}

我的程序的输出是：

 INFO [main] (SLF4JLogger.java:71) - Cluster created with settings {hosts=[127.0.0.1:27017], mode=SINGLE, requiredClusterType=UNKNOWN, serverSelectionTimeout='30000 ms', maxWaitQueueSize=500}
DEBUG [main] (SLF4JLogger.java:56) - Updating cluster description to  {type=UNKNOWN, servers=[{address=127.0.0.1:27017, type=UNKNOWN, state=CONNECTING}]
 INFO [cluster-ClusterId{value='57ab00600aa9452d90826eb8', description='null'}-127.0.0.1:27017] (SLF4JLogger.java:71) - Opened connection [connectionId{localValue:1, serverValue:2}] to 127.0.0.1:27017
DEBUG [cluster-ClusterId{value='57ab00600aa9452d90826eb8', description='null'}-127.0.0.1:27017] (SLF4JLogger.java:56) - Checking status of 127.0.0.1:27017
INFO [cluster-ClusterId{value='57ab00600aa9452d90826eb8', description='null'}-127.0.0.1:27017] (SLF4JLogger.java:71) - Monitor thread successfully connected to server with description ServerDescription{address=127.0.0.1:27017, type=STANDALONE, state=CONNECTED, ok=true, version=ServerVersion{versionList=[3, 2, 8]}, minWireVersion=0, maxWireVersion=4, maxDocumentSize=16777216, roundTripTimeNanos=1163475}
DEBUG [cluster-ClusterId{value='57ab00600aa9452d90826eb8', description='null'}-127.0.0.1:27017] (SLF4JLogger.java:56) - Updating cluster description to  {type=STANDALONE, servers=[{address=127.0.0.1:27017, type=STANDALONE, roundTripTime=1.2 ms, state=CONNECTED}]
Exporting

当我的程序正在运行（或挂起）时，mongo表示我的程序已连接，但未db.currentOp(1)显示任何挂起的写操作。

我也尝试将writeConcern设置为Acknowledged和W1，但这似乎也不起作用。

我也正在使用mongod版本3.2.6和mongo-scala-driver版本1.0.1