在执行jdbc保存时给予空指针异常

Question

嗨，当我执行以下代码行时，我将得到以下堆栈跟踪：

transactionDF.write.format("jdbc")
        .option("url",SqlServerUri)
        .option("driver", driver)
        .option("dbtable", fullQualifiedName)
        .option("user", SqlServerUser).option("password",SqlServerPassword)
        .mode(SaveMode.Append).save()

以下是堆栈跟踪：

at org.apache.spark.sql.catalyst.expressions.GeneratedClass$SpecificUnsafeProjection.apply_3$(Unknown Source)
at org.apache.spark.sql.catalyst.expressions.GeneratedClass$SpecificUnsafeProjection.apply(Unknown Source)
at org.apache.spark.sql.execution.LocalTableScanExec$$anonfun$1.apply(LocalTableScanExec.scala:41)
at org.apache.spark.sql.execution.LocalTableScanExec$$anonfun$1.apply(LocalTableScanExec.scala:41)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:48)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)
at scala.collection.AbstractTraversable.map(Traversable.scala:104)
at org.apache.spark.sql.execution.LocalTableScanExec.<init>(LocalTableScanExec.scala:41)
at org.apache.spark.sql.execution.SparkStrategies$BasicOperators$.apply(SparkStrategies.scala:394)
at org.apache.spark.sql.catalyst.planning.QueryPlanner$$anonfun$1.apply(QueryPlanner.scala:62)
at org.apache.spark.sql.catalyst.planning.QueryPlanner$$anonfun$1.apply(QueryPlanner.scala:62)
at scala.collection.Iterator$$anon$12.nextCur(Iterator.scala:434)
at scala.collection.Iterator$$anon$12.hasNext(Iterator.scala:440)
at scala.collection.Iterator$$anon$12.hasNext(Iterator.scala:439)
at org.apache.spark.sql.catalyst.planning.QueryPlanner.plan(QueryPlanner.scala:92)
at org.apache.spark.sql.catalyst.planning.QueryPlanner$$anonfun$2$$anonfun$apply$2.apply(QueryPlanner.scala:77)
at org.apache.spark.sql.catalyst.planning.QueryPlanner$$anonfun$2$$anonfun$apply$2.apply(QueryPlanner.scala:74)
at scala.collection.TraversableOnce$$anonfun$foldLeft$1.apply(TraversableOnce.scala:157)
at scala.collection.TraversableOnce$$anonfun$foldLeft$1.apply(TraversableOnce.scala:157)
at scala.collection.Iterator$class.foreach(Iterator.scala:893)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1336)
at scala.collection.TraversableOnce$class.foldLeft(TraversableOnce.scala:157)
at scala.collection.AbstractIterator.foldLeft(Iterator.scala:1336)
at org.apache.spark.sql.catalyst.planning.QueryPlanner$$anonfun$2.apply(QueryPlanner.scala:74)
at org.apache.spark.sql.catalyst.planning.QueryPlanner$$anonfun$2.apply(QueryPlanner.scala:66)
at scala.collection.Iterator$$anon$12.nextCur(Iterator.scala:434)
at scala.collection.Iterator$$anon$12.hasNext(Iterator.scala:440)
at org.apache.spark.sql.catalyst.planning.QueryPlanner.plan(QueryPlanner.scala:92)
at org.apache.spark.sql.execution.QueryExecution.sparkPlan$lzycompute(QueryExecution.scala:84)
at org.apache.spark.sql.execution.QueryExecution.sparkPlan(QueryExecution.scala:80)
at org.apache.spark.sql.execution.QueryExecution.executedPlan$lzycompute(QueryExecution.scala:89)
at org.apache.spark.sql.execution.QueryExecution.executedPlan(QueryExecution.scala:89)
at org.apache.spark.sql.execution.QueryExecution$$anonfun$toString$3.apply(QueryExecution.scala:237)
at org.apache.spark.sql.execution.QueryExecution$$anonfun$toString$3.apply(QueryExecution.scala:237)
at org.apache.spark.sql.execution.QueryExecution.stringOrError(QueryExecution.scala:112)
at org.apache.spark.sql.execution.QueryExecution.toString(QueryExecution.scala:237)
at org.apache.spark.sql.execution.SQLExecution$.withNewExecutionId(SQLExecution.scala:54)
at org.apache.spark.sql.Dataset.withNewExecutionId(Dataset.scala:2788)
at org.apache.spark.sql.Dataset.foreachPartition(Dataset.scala:2319)
at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils$.saveTable(JdbcUtils.scala:670)
at org.apache.spark.sql.execution.datasources.jdbc.JdbcRelationProvider.createRelation(JdbcRelationProvider.scala:77)
at org.apache.spark.sql.execution.datasources.DataSource.write(DataSource.scala:518)
at org.apache.spark.sql.DataFrameWriter.save(DataFrameWriter.scala:215)
at com.test.spark.jobs.ingestion.test$.main(test.scala:193)
at com.test.spark.jobs.ingestion.test.main(test.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:743)
at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:187)
at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:212)
at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:126)
at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)

我试过调试它，并且我相信查询执行会导致空指针异常。

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我不知道这是什么意思。我正在本地机器上运行这个程序，而不是在任何集群上运行。

任何帮助都将不胜感激。

Answer 1

我想出来了(Alteast，我认为这就是原因)。对于面临类似情况的其他人:在创建表时，我将每一列设置为null，因此我假设它允许在表中插入空值。但是，我正在构建的Avro模式-- dataframe有nullable = false。因此，dataframe.create读取null，从而引发NPE错误。当我执行Dataframe.write时会引发错误(这使我认为这是jdbc错误)，但是实际的NPE是在创建dataframe时发生的。