Looks like something we should fix though. Probably just needs a case distinction in the TypeExtractor.
@Andrew, can you post the stack trace into the me linked issue? We'll try to get at it until the next release... On Wed, Mar 30, 2016 at 10:58 AM, Chesnay Schepler <ches...@apache.org> wrote: > based on https://issues.apache.org/jira/browse/FLINK-3138 this is not > supported for non-static methods. > > > On 30.03.2016 10:33, Andrew Ge Wu wrote: > > Hi, > > This is not very obvious and looks like a bug. > > I have a lambda expression to get key from objects in stream: > > *This works:* > > stream.keyBy(value -> value.getId()) > > > *This does not:* > > stream.keyBy(myClass::getId) > > > Exception: > > Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1 > at > org.apache.flink.api.java.typeutils.TypeExtractor.getUnaryOperatorReturnType(TypeExtractor.java:294) > at > org.apache.flink.api.java.typeutils.TypeExtractor.getKeySelectorTypes(TypeExtractor.java:253) > at > org.apache.flink.api.java.typeutils.TypeExtractor.getKeySelectorTypes(TypeExtractor.java:246) > at > org.apache.flink.streaming.api.datastream.KeyedStream.<init>(KeyedStream.java:87) > at > org.apache.flink.streaming.api.datastream.DataStream.keyBy(DataStream.java:241) > > > Can someone confirm this? or is there a better way to do it? > > > Thanks! > > > Andrew > > Confidentiality Notice: This e-mail transmission may contain confidential > or legally privileged information that is intended only for the individual > or entity named in the e-mail address. If you are not the intended > recipient, you are hereby notified that any disclosure, copying, > distribution, or reliance upon the contents of this e-mail is strictly > prohibited and may be unlawful. If you have received this e-mail in error, > please notify the sender immediately by return e-mail and delete all copies > of this message. > > >
