java - Vert.x 从 vertx.executeBlocking 做出 promise

Question

我有四个 I/O 操作:A、B、C 和 D。它们中的每一个都应该使用 vertx.executeBlocking 来执行。我应该有以下行为:

//PSEUDOCODE
waitForExecuteBlocking(A_OPERATION);
thenWaitForAllExecuteBlocking(`B_OPERATION`, `C_OPERATION`, `D_OPERATION`)
/* do something */

我怎样才能实现这种行为？

我在 Vertx Rx 中找不到解决方案。我不想将我的 *_OPERATION 类包装为工作垂直体是有原因的。

Answer 1

我正在添加另一个答案，这次是 Futures。
首先请注意，这些是 Vertx future ，而不是常规的 Java future 。使用正确的导入。
现在看代码:

// I'm running in main(), so everything is static, just for the sake of example
private static Vertx vertx = Vertx.vertx();
public static void main(String[] args) throws InterruptedException {


    long start = System.currentTimeMillis();

    // In your case it should be operationA(), operationB(), etc
    // But I wanted to make the code shorter
    CompositeFuture.all(operationA(), operationA(), operationA()).setHandler((r) -> {
        if (r.succeeded()) {
            // You can even iterate all the results
            List<String> results = r.result().list();
            for (String result : results) {
                System.out.println(result);
            }
            // This will still print max(operationA, operationB, operationC)
            System.out.println("Took me " + (System.currentTimeMillis() - start) + " millis");
        }
        else {
            System.out.println("Something went wrong");
        }
    });
}


// Return a future, then fulfill it after some time
private static Future<String> operationA() {
    Future<String> future = Future.future();

    long millis = 1000 + ThreadLocalRandom.current().nextInt(500);
    vertx.setTimer(millis, (l) -> {
        future.complete("All is good " + millis);
    });

    return future;
}