What are some examples of CompletableFuture in Java?

Can you explain what CompletableFuture is in Java?

Sure! CompletableFuture is a class in Java that allows you to write asynchronous, non-blocking code. It represents a future result of an asynchronous computation.

Can you give me some examples of how to use CompletableFuture?

Absolutely! For example, you can use CompletableFuture to run tasks in parallel and combine their results. Here's a simple example:

CompletableFuture<Integer> future1 = CompletableFuture.supplyAsync(() -> 1);
CompletableFuture<Integer> future2 = CompletableFuture.supplyAsync(() -> 2);

CompletableFuture<Integer> combinedFuture = future1.thenCombine(future2, (a, b) -> a + b);

combinedFuture.thenAccept(result -> System.out.println("Result: " + result));

What happens if one of the tasks fails?

If one of the tasks fails, you can handle the exception using the handle or exceptionally methods. For example:

combinedFuture.exceptionally(ex -> {
    System.out.println("Error: " + ex.getMessage());
    return 0;
});

Are there any performance considerations I should be aware of?

Yes, while CompletableFuture can improve performance by running tasks asynchronously, be cautious of thread pool sizes and resource management to avoid overwhelming the system.