Logging Reactor Flows

Debugging after the fact isn’t our only tool in Reactor. It’s possible to log actions as they happen.

Getting data reactively

When we sit down to insert some log.debug() statements into our Reactor code we might find that it’s suddenly not so easy.

This isn’t precisely the fault of Reactive Streams’ asynchronous nature, but instead Project Reactor’s application of functional programming techniques. By using lambda functions and method references, we just don’t have as many places to insert those convenient log.debug() statements.

For example, Java 8 programming lets us write code like this: