[FLINK-5070] Unable to use Scala's BeanProperty with classes

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.1.3
• Fix Version/s: 1.3.0, 1.4.0
• Component/s: API / Scala, API / Type Serialization System
• Assignee: Timo Walther
• Reporter: Jakub Nowacki
• Created: 15/Nov/16 11:39
• Updated: 28/Feb/19 13:21
• Resolved: 09/May/17 18:53

Description

When using Scala class with with property (both var and val) annotated as BeanProperty, throws an exception java.lang.IllegalStateException: Detected more than one getter.

The simple code which follows throws that exception:

class SomeClass(@BeanProperty var prop: Int)

object SampleBeanProperty {
    def main(args: Array[String]): Unit = {
        val env = StreamExecutionEnvironment.createLocalEnvironment()

        // Create a DataSet from a list of elements
        env.fromElements(1,2)
            .map(new SomeClass(_))
            .print

        env.execute()
    }
}

Full exception:

Exception in thread "main" java.lang.IllegalStateException: Detected more than one setter
	at org.apache.flink.api.java.typeutils.TypeExtractor.isValidPojoField(TypeExtractor.java:1646)
	at org.apache.flink.api.java.typeutils.TypeExtractor.analyzePojo(TypeExtractor.java:1692)
	at org.apache.flink.api.java.typeutils.TypeExtractor.privateGetForClass(TypeExtractor.java:1580)
	at org.apache.flink.api.java.typeutils.TypeExtractor.privateGetForClass(TypeExtractor.java:1479)
	at org.apache.flink.api.java.typeutils.TypeExtractor.createTypeInfoWithTypeHierarchy(TypeExtractor.java:737)
	at org.apache.flink.api.java.typeutils.TypeExtractor.privateCreateTypeInfo(TypeExtractor.java:543)
	at org.apache.flink.api.java.typeutils.TypeExtractor.createTypeInfo(TypeExtractor.java:497)
	at org.apache.flink.api.java.typeutils.TypeExtractor.createTypeInfo(TypeExtractor.java:493)
	at SampleBeanProperty$.main(SampleBeanProperty.scala:18)
	at SampleBeanProperty.main(SampleBeanProperty.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 com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)

If the class is changed into case class, code with BeanProperty works fine.

Issue Links

• links to: GitHub Pull Request #3318