6 · Advanced · lesson 36 of 41

CompletableFuture

Composable async pipelines.

Java

CompletableFuture<String> page = CompletableFuture
    .supplyAsync(() -> fetch(url))
    .thenApply(String::trim)
    .thenCombine(
        CompletableFuture.supplyAsync(() -> fetch(url2)),
        (a, b) -> a + b)
    .exceptionally(err -> "fallback");

String result = page.join();

Key takeaways

✓thenApply/thenCombine chain non-blocking steps.
✓exceptionally / handle recover from failures.

← Back to Java playground