Corotinas em Kotlin

Corotina.kt

package com.guiathayde.lib

import kotlinx.coroutines.Deferred
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.async
import kotlinx.coroutines.awaitAll
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking
import kotlin.random.Random
import kotlin.time.Duration.Companion.seconds

fun randomSeconds(): Int {
    return Random.nextInt(5, 15)
}

suspend fun callWebAPI1(): String {
    println("Start call to API 1 ...")
    val myDelay = randomSeconds()
    delay(myDelay.seconds)
    return "Data 1 returned in $myDelay seconds."
}

suspend fun callWebAPI2(): String {
    println("Start call to API 2 ...")
    val myDelay = randomSeconds()
    delay(myDelay.seconds)
    return "Data 2 returned in $myDelay seconds."
}

fun main() = runBlocking {
    launch {
        val deferredA: Deferred<String> = async(Dispatchers.IO) {
            callWebAPI1()
        }
        val deferredB: Deferred<String> = async(Dispatchers.IO) {
            callWebAPI2()
        }

        val res = listOf(deferredA, deferredB).awaitAll()
        println(res)
    }

    println("End of runBlocking")
}