Promise【其他模式】

Promise

@Slf4j
public class Promise {
    /**
     * Promise Pattern【承诺】：承诺表示当前还未完成，但是会在将来完成的操作，用于实现异步计算。
     */
    @Test
    public void all() throws InterruptedException, ExecutionException {
        final CompletableFuture<String> future = CompletableFuture.supplyAsync(() -> {
            try {
                TimeUnit.SECONDS.sleep(2);
            } catch (final InterruptedException e1) {
                throw new RuntimeException(e1);
            }
            return "hello";
        }).exceptionally(e -> {
            log.error("error happened", e);
            return "error";
        });
        final String result = future.get();
        assertEquals("hello", result);
    }
}