One more simple example with futures

Author: elizarov

kotlinx-coroutines-jdk8/src/test/kotlin/examples/simple-example-3.kt

@@ -0,0 +1,22 @@
+package examples
+
+import kotlinx.coroutines.experimental.future.await
+import kotlinx.coroutines.experimental.future.future
+import java.util.concurrent.CompletableFuture
+
+fun main(args: Array<String>) {
+    // this example shows how easy it is to perform multiple async operations with coroutines
+    val future = future {
+        (1..5).map { // loops are no problem at all
+            startLongAsyncOperation(it).await() // suspend while the long method is running
+        }.joinToString("\n")
+    }
+    println("We have a long-running computation in background, let's wait for its result...")
+    println(future.get())
+}
+
+fun startLongAsyncOperation(num: Int): CompletableFuture<String> =
+    CompletableFuture.supplyAsync {
+        Thread.sleep(1000L) // imitate some long-running computation, actually
+        "$num" // and return a number converted to string
+    }