How to get the cartesian product of two DStream in

问题:

I have two DStreams. Let A:DStream[X] and B:DStream[Y].

I want to get the cartesian product of them, in other words, a new C:DStream[(X, Y)] containing all the pairs of X and Y values.

I know there is a cartesian function for RDDs. I was only able to find this similar question but it's in Java and so does not answer my question.

回答1:

The Scala equivalent of the linked question's answer (ignoring Time v3, which isn't used there) is

A.transformWith(B, (rddA: RDD[X], rddB: RDD[Y]) => rddA.cartesian(rddB))

or shorter

A.transformWith(B, (_: RDD[X]).cartesian(_: RDD[Y]))