Common coroutine exception handler for Vert.x handlers

[Dmitriy Bykov]

Hi.

I'm new both to Vert.x and Kotlin, and I'm trying to figure out an optimal way to dealing with exceptions in event handlers.

I want to log exceptions happening in those handlers throughout the application, with minimal boilerplate code.

Let's say, I have this doStuff() method that fails every now and then:

class MainVerticle : CoroutineVerticle() {

    override suspend fun start() {

        vertx.setPeriodic(1000) {

            launch {

                doStuff()

            }

        }

    }

    private suspend fun doStuff() {

        delay(500)

        if (Random.nextInt(5) == 0) {

            throw RuntimeException("Something bad just happened")

        }

        println("Job done")

    }

}

If the method throws an exception, I need just to log this event and continue app execution. Vertx.exceptionHandler is not fired in this case.

Here I found that there's a way to use the launch() method with the custom CoroutineExceptionHandler. It works, but it looks slightly cumbersome to me - it's easy to forget to supply this handler and miss exceptions, especially when there are many launch() invocations exist.

Is there a better way to catch those exceptions globally per verticle or per Vertx instance?