我可以将 Publisher 的结果传递给 Reactor Context 吗？

Question

I have a io.grpc.Context that comes from a Publisher. Can I pass write that into the Reactor Context?

Mono.just(io.grpc.Context.current())
  .contextWrite(grpcContext -> 
    reactor.util.context.Context.of(MY_KEY, grpcContext))

Is something like that possible? The reason is because I have a OnNextOperator hook that I want to listen for this change in grpc.Context

Answer 1

Is something like that possible?

Not if you want to access the context downstream - context injection is part of the subscription signal, which flows upstream from bottom to top. This is in contrast to the other reactive signals ( next , error ) which flow downstream from top to bottom.

Your only sensible option if you want to read a value like this downstream is to include it as part of the element itself - usually by using zip() , zipWith() or similar.