Issue with scala: java.lang.NoClassDefFoundError: scala/$less$colon$less

[coperator]

In an openjdk docker image I installed python and, then, pyspark with pip and used

spark = SparkSession.builder.appName("MyApp") \
            .config("spark.jars.packages", "com.databricks:spark-xml_2.13:0.16.0") \
            .getOrCreate()

to load spark-xml. When calling

dataFrame = spark.read\
    .format("xml")\
    .option("rowTag", "Obs")\
    .load("/data/test.xml")

I get the following error:

raceback (most recent call last):
  File "<stdin>", line 4, in <module>
  File "/usr/local/lib/python3.7/site-packages/pyspark/sql/readwriter.py", line 158, in load
    return self._df(self._jreader.load(path))
  File "/usr/local/lib/python3.7/site-packages/py4j/java_gateway.py", line 1310, in __call__
    answer, self.gateway_client, self.target_id, self.name)
  File "/usr/local/lib/python3.7/site-packages/pyspark/sql/utils.py", line 111, in deco
    return f(*a, **kw)
  File "/usr/local/lib/python3.7/site-packages/py4j/protocol.py", line 328, in get_return_value
    format(target_id, ".", name), value)
py4j.protocol.Py4JJavaError: An error occurred while calling o35.load.
: java.lang.NoClassDefFoundError: scala/$less$colon$less
    at com.databricks.spark.xml.XmlOptions$.apply(XmlOptions.scala:82)
    at com.databricks.spark.xml.DefaultSource.createRelation(DefaultSource.scala:66)
    at com.databricks.spark.xml.DefaultSource.createRelation(DefaultSource.scala:52)
    at org.apache.spark.sql.execution.datasources.DataSource.resolveRelation(DataSource.scala:350)
    at org.apache.spark.sql.DataFrameReader.loadV1Source(DataFrameReader.scala:274)
    at org.apache.spark.sql.DataFrameReader.$anonfun$load$3(DataFrameReader.scala:245)
    at scala.Option.getOrElse(Option.scala:189)
    at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:245)
    at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:188)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at py4j.reflection.MethodInvoker.invoke(MethodInvoker.java:244)
    at py4j.reflection.ReflectionEngine.invoke(ReflectionEngine.java:357)
    at py4j.Gateway.invoke(Gateway.java:282)
    at py4j.commands.AbstractCommand.invokeMethod(AbstractCommand.java:132)
    at py4j.commands.CallCommand.execute(CallCommand.java:79)
    at py4j.ClientServerConnection.waitForCommands(ClientServerConnection.java:182)
    at py4j.ClientServerConnection.run(ClientServerConnection.java:106)
    at java.lang.Thread.run(Thread.java:750)
Caused by: java.lang.ClassNotFoundException: scala.$less$colon$less
    at java.net.URLClassLoader.findClass(URLClassLoader.java:387)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
    ... 21 more

What am I missing?

[coperator]

Is it a version mismatch issue? I used pyspark version 3.2.0, openjdk version 8, python version 3.9.8 and com.databricks:spark-xml_2.13:0.16.0

[srowen]

It is, a Scala version mismatch. You are probably using Scala 2.12, but have added the 2.13 artifact. Use _2.12

[coperator]

Ah, yes! Thank you for the quick reply. Easy to miss. Maybe it would be good to highlight the fact that the versions must match in the documentation of spark-xml. So, default of Spark and PySpark is currently still scala 2.12.

[srowen]

That's just true of any Scala dependency though, I think many people would know that and/or you'd find that with other libraries