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#spring
Title
d

Dariusz Kuc

09/26/2019, 4:25 AM
hello! does anyone know what is the proper way to invoke coroutines from Spring WebFilters? e.g. something like this works and populates the context as expected
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class FooFilter : WebFilter {
    override fun filter(exchange: ServerWebExchange, chain: WebFilterChain): Mono<Void> = mono {
        foo()
    }.flatMap { foo ->
        chain.filter(exchange).subscriberContext { it.put("foo", foo) }
    }
    
    suspend fun foo(): Foo { ... }
}
problem arise if there is another webfilter populates subscriber context BEFORE this filter and we would like to also access it in 
foo()
with latest spring boot and coroutines we do have a nice interop between them, e.g. we can access reactor context from coroutine context
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val bar = coroutineContext[ReactorContext]?.context?.get<Bar>("bar")
but in the example above, when executing 
FooFilter
our reactor context is empty
any ideas/suggestions?
so doing it like this
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Mono.subscriberContext()
    .flatMap { ctx ->
        val foo = runBlocking(ctx.asCoroutineContext()) {
          foo()
        }
        chain.filter(exchange).subscriberContext { it.put("foo", foo) }
    }
seems to work... but that 
runBlocking
there seems just wrong
... weird... original one using 
mono { foo() }
started working for me
nvm
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