Completable Futures
CompletableFuture is a class introduced in Java 8 to support asynchronous and concurrent programming. It represents a computation that may or may not have completed yet and provides a way to chain dependent computations, handle exceptions, and compose multiple CompletableFuture instances.
Creating a CompletableFuture
To create a CompletableFuture, you can use the CompletableFuture constructor, which creates an incomplete CompletableFuture that can be completed manually later. Here's an example:
TEXT/X-JAVA
1CompletableFuture<String> completableFuture = new CompletableFuture<>();xxxxxxxxxx29
import java.util.concurrent.CompletableFuture;public class Main { public static void main(String[] args) { // Create a CompletableFuture CompletableFuture<String> completableFuture = new CompletableFuture<>(); // Perform some async task new Thread(() -> { try { // Simulate a long-running task Thread.sleep(2000); // Complete the CompletableFuture with a result completableFuture.complete("Async task completed!"); } catch (InterruptedException e) { // Handle any exceptions completableFuture.completeExceptionally(e); } }).start(); // Get the result from the CompletableFuture completableFuture.thenAccept(result -> { System.out.println(result); }); System.out.println("Waiting for async task to complete..."); }}OUTPUT
:001 > Cmd/Ctrl-Enter to run, Cmd/Ctrl-/ to comment