How can I use CompletableFuture for advanced asynchronous programming in Java?

How can I use CompletableFuture for advanced asynchronous programming in Java?

You can use CompletableFuture to handle complex asynchronous tasks, allowing you to combine multiple futures, handle exceptions, and apply transformations.

Can you give me an example of combining multiple CompletableFutures?

Sure! You can use CompletableFuture.allOf() to wait for multiple futures to complete. For example:

CompletableFuture<Void> future1 = CompletableFuture.supplyAsync(() -> { /* task 1 */ });
CompletableFuture<Void> future2 = CompletableFuture.supplyAsync(() -> { /* task 2 */ });
CompletableFuture<Void> combined = CompletableFuture.allOf(future1, future2);
combined.join(); // Waits for both to complete

What about error handling with CompletableFuture?

You can handle errors using the exceptionally() method. For example:

CompletableFuture.supplyAsync(() -> { /* task */ })
    .exceptionally(ex -> { /* handle exception */ return null; });

How do I chain multiple asynchronous tasks together?

You can chain tasks using the thenApply() or thenCompose() methods. For example:

CompletableFuture.supplyAsync(() -> { /* task 1 */ })
    .thenApply(result -> { /* process result */ })
    .thenCompose(result -> CompletableFuture.supplyAsync(() -> { /* task 2 */ }));