Need some help to understand the cause of the error

[nsengupta]

Hello Aljoscha,

I have also tried by using the field's name in the sum("field3") function (like you have suggested), but this time the exception is different:

--------------------------------------------------------------------

Exception in thread "main" java.lang.ExceptionInInitializerError

at org.apache.flink.quickstart.StreamWindowExperiments.MultiWindowing.main(MultiWindowing.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:497)

at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)

Caused by: java.lang.IllegalArgumentException: Key expressions are only supported on POJO types and Tuples. A type is considered a POJO if all its fields are public, or have both getters and setters defined

at org.apache.flink.streaming.util.FieldAccessor$PojoFieldAccessor.<init>(FieldAccessor.java:175)

at org.apache.flink.streaming.util.FieldAccessor.create(FieldAccessor.java:92)

at org.apache.flink.streaming.api.functions.aggregation.SumAggregator.<init>(SumAggregator.java:49)

at org.apache.flink.streaming.api.datastream.WindowedStream.sum(WindowedStream.java:390)

at org.apache.flink.quickstart.StreamWindowExperiments.MultiWindowing$.<init>(MultiWindowing.scala:63)

at org.apache.flink.quickstart.StreamWindowExperiments.MultiWindowing$.<clinit>(MultiWindowing.scala)

... 6 more

---------------------------------------------------------------------

I have used both of the styles of calling sum() in earlier, but I never got this exception. That's why I am a little confused. 'Reading' is a _case class_ and hence, a POJO as I understand. Yet, the message seems to say that it is not.

--  Nirmalya

--

[Aljoscha Krettek]

Hi,
which version of Flink are you using, by the way? This would help me narrow down on possible causes of the problem.

Cheers,
Aljoscha

> On 26 Feb 2016, at 10:34, Nirmalya Sengupta <[hidden email]> wrote:
>
> Hello Aljoscha,
>
> I have also tried by using the field's name in the sum("field3") function (like you have suggested), but this time the exception is different:
>
> --------------------------------------------------------------------
>
> Exception in thread "main" java.lang.ExceptionInInitializerError
> at org.apache.flink.quickstart.StreamWindowExperiments.MultiWindowing.main(MultiWindowing.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:497)
> at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)
> Caused by: java.lang.IllegalArgumentException: Key expressions are only supported on POJO types and Tuples. A type is considered a POJO if all its fields are public, or have both getters and setters defined
> at org.apache.flink.streaming.util.FieldAccessor$PojoFieldAccessor.<init>(FieldAccessor.java:175)
> at org.apache.flink.streaming.util.FieldAccessor.create(FieldAccessor.java:92)
> at org.apache.flink.streaming.api.functions.aggregation.SumAggregator.<init>(SumAggregator.java:49)
> at org.apache.flink.streaming.api.datastream.WindowedStream.sum(WindowedStream.java:390)
> at org.apache.flink.quickstart.StreamWindowExperiments.MultiWindowing$.<init>(MultiWindowing.scala:63)
> at org.apache.flink.quickstart.StreamWindowExperiments.MultiWindowing$.<clinit>(MultiWindowing.scala)
> ... 6 more
>
> ---------------------------------------------------------------------
>
> I have used both of the styles of calling sum() in earlier, but I never got this exception. That's why I am a little confused. 'Reading' is a _case class_ and hence, a POJO as I understand. Yet, the message seems to say that it is not.
>
> --  Nirmalya
>
> --
> Software Technologist
> http://www.linkedin.com/in/nirmalyasengupta
> "If you have built castles in the air, your work need not be lost. That is where they should be.
> Now put the foundation under them."

[nsengupta]

Hello  Aljoscha,

I am using Flink 0.10.1 (see below) and flinkspector (0.1-SNAPSHOT).

---------------------------------------------------------------------------------

<dependency>

<groupId>org.apache.flink</groupId>

<artifactId>flink-scala</artifactId>

<version>0.10.1</version>

</dependency>

<dependency>

<groupId>org.apache.flink</groupId>

<artifactId>flink-streaming-scala</artifactId>

<version>0.10.1</version>

</dependency>

<dependency>

<groupId>org.apache.flink</groupId>

<artifactId>flink-clients</artifactId>

<version>0.10.1</version>

</dependency>

                <dependency>

  <groupId>com.dataArtisans</groupId>

  <artifactId>flink-training-exercises</artifactId>

  <version>0.1</version>

<dependency>
   <groupId>org.flinkspector</groupId>
   <artifactId>flinkspector-datastream</artifactId>
   <version>0.1-SNAPSHOT</version>
</dependency>

</dependency>

-----------------------------------------------------

Many thanks in advance for your effort.

-- Nirmalya

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