Description
A confusing experience happens when users accidentally package the Scala Library into their jar file. The reversed class loading duplicates Scala's classes, leading to exceptions like the one below.
By adding scala. to the default 'parent-first-patterns' we can improve the user experience in such situations.
Exception Stack Trace:
java.lang.ClassCastException: cannot assign instance of org.peopleinmotion.TestFunction$$anonfun$1 to field org.apache.flink.streaming.api.scala.DataStream$$anon$7.cleanFun$6 of type scala.Function1 in instance of org.apache.flink.streaming.api.scala.DataStream$$anon$7
at java.io.ObjectStreamClass$FieldReflector.setObjFieldValues(ObjectStreamClass.java:2233)
at java.io.ObjectStreamClass.setObjFieldValues(ObjectStreamClass.java:1405)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2288)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2206)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2064)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1568)
at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:2282)
at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:2206)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2064)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1568)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:428)
at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:290)
at org.apache.flink.util.InstantiationUtil.readObjectFromConfig(InstantiationUtil.java:248)
at org.apache.flink.streaming.api.graph.StreamConfig.getStreamOperator(StreamConfig.java:220)
... 6 more
Attachments
Issue Links
- supercedes
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FLINK-8256 Cannot use Scala functions to filter in 1.4 - java.lang.ClassCastException
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- Closed
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- links to
