scala - 线程“main”中的异常 java.lang.NullPointerException com.databricks.dbutils_v1.DBUtilsHolder$$anon$1.invoke

Question

我想在 Azure Blob 中读取 parquet 文件，因此我已将 Azure Blob 中的数据挂载到本地，dbultils.fs.mount
但出现错误Exception in thread "main" java.lang.NullPointerException
以下是我的日志：

hello big data
Using Spark's default log4j profile: org/apache/spark/log4j-defaults.properties
20/06/10 23:20:10 INFO SparkContext: Running Spark version 2.1.0
20/06/10 23:20:11 WARN NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
20/06/10 23:20:11 INFO SecurityManager: Changing view acls to: Admin
20/06/10 23:20:11 INFO SecurityManager: Changing modify acls to: Admin
20/06/10 23:20:11 INFO SecurityManager: Changing view acls groups to: 
20/06/10 23:20:11 INFO SecurityManager: Changing modify acls groups to: 
20/06/10 23:20:11 INFO SecurityManager: SecurityManager: authentication disabled; ui acls disabled; users  with view permissions: Set(Admin); groups with view permissions: Set(); users  with modify permissions: Set(Admin); groups with modify permissions: Set()
20/06/10 23:20:12 INFO Utils: Successfully started service 'sparkDriver' on port 4725.
20/06/10 23:20:12 INFO SparkEnv: Registering MapOutputTracker
20/06/10 23:20:13 INFO SparkEnv: Registering BlockManagerMaster
20/06/10 23:20:13 INFO BlockManagerMasterEndpoint: Using org.apache.spark.storage.DefaultTopologyMapper for getting topology information
20/06/10 23:20:13 INFO BlockManagerMasterEndpoint: BlockManagerMasterEndpoint up
20/06/10 23:20:13 INFO DiskBlockManager: Created local directory at C:\Users\Admin\AppData\Local\Temp\blockmgr-c023c3b8-fd70-461a-ac69-24ce9c770efe
20/06/10 23:20:13 INFO MemoryStore: MemoryStore started with capacity 894.3 MB
20/06/10 23:20:13 INFO SparkEnv: Registering OutputCommitCoordinator
20/06/10 23:20:13 INFO Utils: Successfully started service 'SparkUI' on port 4040.
20/06/10 23:20:13 INFO SparkUI: Bound SparkUI to 0.0.0.0, and started at http://192.168.0.102:4040
20/06/10 23:20:13 INFO Executor: Starting executor ID driver on host localhost
20/06/10 23:20:13 INFO Utils: Successfully started service 'org.apache.spark.network.netty.NettyBlockTransferService' on port 4738.
20/06/10 23:20:13 INFO NettyBlockTransferService: Server created on 192.168.0.102:4738
20/06/10 23:20:13 INFO BlockManager: Using org.apache.spark.storage.RandomBlockReplicationPolicy for block replication policy
20/06/10 23:20:13 INFO BlockManagerMaster: Registering BlockManager BlockManagerId(driver, 192.168.0.102, 4738, None)
20/06/10 23:20:13 INFO BlockManagerMasterEndpoint: Registering block manager 192.168.0.102:4738 with 894.3 MB RAM, BlockManagerId(driver, 192.168.0.102, 4738, None)
20/06/10 23:20:13 INFO BlockManagerMaster: Registered BlockManager BlockManagerId(driver, 192.168.0.102, 4738, None)
20/06/10 23:20:13 INFO BlockManager: Initialized BlockManager: BlockManagerId(driver, 192.168.0.102, 4738, None)
20/06/10 23:20:14 INFO SharedState: Warehouse path is 'file:/E:/sparkdemo/sparkdemo/spark-warehouse/'.
Exception in thread "main" java.lang.NullPointerException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.databricks.dbutils_v1.DBUtilsHolder$$anon$1.invoke(DBUtilsHolder.scala:17)
    at com.sun.proxy.$Proxy7.fs(Unknown Source)
    at Transform$.main(Transform.scala:19)
    at Transform.main(Transform.scala)
20/06/10 23:20:14 INFO SparkContext: Invoking stop() from shutdown hook
20/06/10 23:20:14 INFO SparkUI: Stopped Spark web UI at http://192.168.0.102:4040
20/06/10 23:20:14 INFO MapOutputTrackerMasterEndpoint: MapOutputTrackerMasterEndpoint stopped!
20/06/10 23:20:14 INFO MemoryStore: MemoryStore cleared
20/06/10 23:20:14 INFO BlockManager: BlockManager stopped
20/06/10 23:20:14 INFO BlockManagerMaster: BlockManagerMaster stopped
20/06/10 23:20:14 INFO OutputCommitCoordinator$OutputCommitCoordinatorEndpoint: OutputCommitCoordinator stopped!
20/06/10 23:20:14 INFO SparkContext: Successfully stopped SparkContext
20/06/10 23:20:14 INFO ShutdownHookManager: Shutdown hook called
20/06/10 23:20:14 INFO ShutdownHookManager: Deleting directory C:\Users\Admin\AppData\Local\Temp\spark-cbdbcfe7-bc70-4d34-ad8e-5baed8308ae2

我的代码：

import com.databricks.dbutils_v1.DBUtilsHolder.dbutils
import org.apache.spark.sql.SparkSession

object Demo {
  def main(args:Array[String]): Unit = {
    println("hello big data")
    val containerName = "container1"
    val storageAccountName = "storageaccount1"
    val sas = "saskey"

    val url = "wasbs://" + containerName + "@" + storageAccountName + ".blob.core.windows.net/"
    var config = "fs.azure.sas." + containerName + "." + storageAccountName + ".blob.core.windows.net"
    //Spark session
    val spark : SparkSession = SparkSession.builder
      .appName("SpartDemo")
      .master("local[1]")
      .getOrCreate()
    //Mount data
    dbutils.fs.mount(
      source = url,
      mountPoint = "/mnt/container1",
      extraConfigs = Map(config -> sas))

    val parquetFileDF = spark.read.parquet("/mnt/container1/test1.parquet")

    parquetFileDF.show()

  }
}

我的 sbt 文件：

name := "sparkdemo1"

version := "0.1"

scalaVersion := "2.11.8"

libraryDependencies ++= Seq(
  "com.databricks" % "dbutils-api_2.11" % "0.0.3",
  "org.apache.spark" % "spark-core_2.11" % "2.1.0",
  "org.apache.spark" % "spark-sql_2.11" % "2.1.0"
)

标签： scalaapache-sparksbtazure-blob-storagedbutils

Answer 1

您是否将其运行到 Databricks 实例中？如果不是，那就是问题所在：dbutils 由 Databricks 执行上下文提供。在这种情况下，据我所知，您有三个选择：

1. 将您的应用程序打包到 jar 文件中并使用 Databricks 作业运行它
2. 使用数据块连接

3. 尝试在 Databricks 之外模拟一个模拟的 dbutils 实例，如下所示：

   com.databricks.dbutils_v1.DBUtilsHolder.dbutils0.set(
     new com.databricks.dbutils_v1.DBUtilsV1{
       ...
     }
   )
   

无论如何，我会说选项 1 和 2 比第三个更好。此外，通过选择其中一个，您不需要包含“dbutils-api_2.11”依赖项，因为它由 Databricks 集群提供。