Hello if my presenter is written in java and my datasource is in kotlin and I have used coroutines, ...

# coroutines

[Pablo]

Hello if my presenter is written in java and my datasource is in kotlin and I have used coroutines, how do I connect them? Do I have to use the suspendCancelableCoroutine{..} ? Then do i need the launch{} somewhere? Or from the java class I call the method of my presenter and that's it? I can avoid the launch?

[diesieben07]

Java cannot interact with suspending functions in a meaningful way. You have to expose any suspending functions that you want to use from Java in a way that Java can consume - i.e. as a CompletableFuture or something similar.
E.g.:

suspend fun doSomething(): String = TODO()
fun doSomethingFutureAsync(): CompletableFuture<String> = future { doSomething() }

This uses future from `kotlinx-coroutines-jdk8`: https://github.com/Kotlin/kotlinx.coroutines/tree/master/integration/kotlinx-coroutines-jdk8.

[Pablo]

so no matter what I need to do a suspend fun?

[Pablo]

I mean if my presenter is in Java and I have a datasource that has de suspendCancellableCOroutine this method has to be suspend right? otherwise it won't work

[diesieben07]

Well, you can also just do

future {
    // suspending code here
}

Which produces a CompletableFuture directly - and lets you suspend.