Java Run Multiple APIs same time, collect Request List which failed

Question

I am running same API multiple times for a List in parallel to save time. I have input List of ProductIds and API returns an Output ProductResponse with successFlag and TransactionId.

1 I am trying to run them all, the other API calls should continue even if one fails.

2 And then collect all ProductId Number Requests which fail. How would I collect the original request list that failed? Trying to modify code below.

public runAllAPIs() {

    List<Integer> productIds = Arrays.asList(2,5,7);

    List<CompletableFuture<ProductResponse>> productFutures =
                    productIds.stream()
                            .map(productIdItems -> createProduct(productId)
                            .collect(Collectors.toList());

    List<ProductResponse> productResponses =
                    productFutures.stream()
                            .map(CompletableFuture::join)
                            .collect(Collectors.toList());

    // how to print which productIds requests failed here
}

private CompletableFuture<ProductResponse> createProduct(int productId){
    return CompletableFuture.supplyAsync(() -> productAPI.createProduct(productId);
}

@Data
public class ProductResponse {
  private boolean isSuccessAPI;
  private int transactionId;
}

Note: the Response Object does not contain ProductId in request.

Answer 1

@Test
public void test() {
    List<Integer> productIds = Arrays.asList(2, 5, 7);

    List<CompletableFuture<MyCustomProductResponse>> productFutures =
            productIds.stream()
                    .map(productId -> createProduct(productId))
                    .collect(Collectors.toList());

    List<MyCustomProductResponse> productResponses =
            productFutures.stream()
                    .map(CompletableFuture::join)
                    .collect(Collectors.toList());

    // how to print which productIds requests failed here
    productResponses.forEach(pr -> {
        if (!pr.apiResponse.isSuccessAPI) {
            System.out.println(pr.productId);
        }
    });
}

private CompletableFuture<MyCustomProductResponse> createProduct(int productId) {
    return CompletableFuture.supplyAsync(() -> {
        try {
            Thread.sleep(1000);
            // This is what you get from API
            ProductResponseFromAPI apiResponse = new ProductResponseFromAPI(new Random().nextBoolean(), new Random().nextInt());
            //You wrap that in your own object
            return new MyCustomProductResponse(productId, apiResponse);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
    });
}

@Value
static class ProductResponseFromAPI {
    private boolean isSuccessAPI;
    private int productTransactionId;
}

@Value
static class MyCustomProductResponse {
    private int productId;
    private ProductResponseFromAPI apiResponse;
}