Im trying to use JsonSource and write it as Parquet using ParquetSink. The issue I'm running into is that I get a ClassCastException whenever the Parquet writer encounters a Row created from json with an array of objects. From what I see, it's because the writer is trying to cast a scala Map to a Seq[Any] in the StructWriter.
Here is where the exception is thrown: https://github.com/51zero/eel-sdk/blob/v1.2.4/eel-core/src/main/scala/io/eels/component/parquet/RecordConsumerWriter.scala#L105
Here is the stack trace:
Exception in thread "main" java.lang.ClassCastException: scala.collection.immutable.Map$Map1 cannot be cast to scala.collection.Seq
at io.eels.component.parquet.StructWriter.write(RecordConsumerWriter.scala:105)
at io.eels.component.parquet.ArrayParquetWriter.$anonfun$write$2(RecordConsumerWriter.scala:84)
at io.eels.component.parquet.ArrayParquetWriter.$anonfun$write$2$adapted(RecordConsumerWriter.scala:81)
at scala.collection.Iterator.foreach(Iterator.scala:941)
at scala.collection.Iterator.foreach$(Iterator.scala:941)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1429)
at scala.collection.IterableLike.foreach(IterableLike.scala:74)
at scala.collection.IterableLike.foreach$(IterableLike.scala:73)
at scala.collection.AbstractIterable.foreach(Iterable.scala:56)
at io.eels.component.parquet.ArrayParquetWriter.write(RecordConsumerWriter.scala:81)
at io.eels.component.parquet.StructWriter.$anonfun$write$3(RecordConsumerWriter.scala:113)
at scala.collection.immutable.Range.foreach$mVc$sp(Range.scala:158)
at io.eels.component.parquet.StructWriter.write(RecordConsumerWriter.scala:106)
at io.eels.component.parquet.RowWriter.write(RowWriteSupport.scala:42)
at io.eels.component.parquet.RowWriteSupport.write(RowWriteSupport.scala:33)
at io.eels.component.parquet.RowWriteSupport.write(RowWriteSupport.scala:15)
at org.apache.parquet.hadoop.InternalParquetRecordWriter.write(InternalParquetRecordWriter.java:128)
at org.apache.parquet.hadoop.ParquetWriter.write(ParquetWriter.java:299)
at io.eels.component.parquet.ParquetSink$$anon$1.write(ParquetSink.scala:35)
at io.eels.datastream.SinkAction$$anon$2.$anonfun$run$3(SinkAction.scala:54)
at io.eels.datastream.SinkAction$$anon$2.$anonfun$run$3$adapted(SinkAction.scala:53)
at scala.collection.immutable.List.foreach(List.scala:392)
at io.eels.datastream.SinkAction$$anon$2.$anonfun$run$2(SinkAction.scala:53)
at io.eels.datastream.SinkAction$$anon$2.$anonfun$run$2$adapted(SinkAction.scala:52)
at scala.collection.Iterator.foreach(Iterator.scala:941)
at scala.collection.Iterator.foreach$(Iterator.scala:941)
at scala.collection.AbstractIterator.foreach(Iterator.scala:1429)
at io.eels.datastream.SinkAction$$anon$2.run(SinkAction.scala:52)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Here is a fully runnable example (will need hadoop deps if you don't already have them):
import java.io.{ByteArrayInputStream, File, FileInputStream}
import java.nio.charset.StandardCharsets
import io.eels.component.json.JsonSource
import io.eels.component.parquet.ParquetSink
import org.apache.hadoop.conf.Configuration
import org.apache.hadoop.fs.{FileSystem, Path}
object ArrayOfObjectsTest extends App {
// Setup Filesystem
val hadoopConf = new Configuration()
hadoopConf.addResource(
new FileInputStream(new File(getClass.getResource("/hadoop/core-site.xml").toURI))
)
hadoopConf.set("fs.file.impl", classOf[org.apache.hadoop.fs.LocalFileSystem].getName)
implicit val fs: FileSystem = FileSystem.get(hadoopConf)
// Setup Parquet Sink
// Intentionally just overwrite the same file
private val hadoopPath = s"/tmp/parquet-test"
private val sink = ParquetSink(fs.makeQualified(new Path(hadoopPath)))
.withOverwrite(true)
// Setup JSON source with constant JSON value
// Notice the `objectArray` field is an array of objects
val source = JsonSource(() => {
val jsonString = """
{"objectArray":[{"key1":"value1"}]}
""".stripMargin
new ByteArrayInputStream(jsonString.getBytes(StandardCharsets.UTF_8))
})
// This throws: java.lang.ClassCastException: scala.collection.immutable.Map$Map1 cannot be cast to scala.collection.Seq
source.toDataStream().to(sink)
}core-site.xml file for local hadoop dev (I put this in my resources folder in a hadoop sub directory):
<configuration>
<property>
<name>hadoop.tmp.dir</name>
<value>/tmp</value>
</property>
<property>
<name>fs.default.name</name>
<value>file:///</value>
</property>
</configuration>I do realize that this is on version 1.2.4 of eels but there is no later version for scala 2.12 on Maven. Can you see any reason why Im getting this writer error? If it's an actual bug I'd be happy to take a stab at fixing it.
Im trying to use
JsonSourceand write it as Parquet usingParquetSink. The issue I'm running into is that I get aClassCastExceptionwhenever the Parquet writer encounters aRowcreated from json with an array of objects. From what I see, it's because the writer is trying to cast a scalaMapto aSeq[Any]in theStructWriter.Here is where the exception is thrown: https://github.com/51zero/eel-sdk/blob/v1.2.4/eel-core/src/main/scala/io/eels/component/parquet/RecordConsumerWriter.scala#L105
Here is the stack trace:
Here is a fully runnable example (will need hadoop deps if you don't already have them):
core-site.xmlfile for local hadoop dev (I put this in my resources folder in ahadoopsub directory):I do realize that this is on version
1.2.4of eels but there is no later version for scala 2.12 on Maven. Can you see any reason why Im getting this writer error? If it's an actual bug I'd be happy to take a stab at fixing it.