流供应商收到错误消息'流已被操作或关闭'

Question

即使我每次都想使用供应商并在每次要检索我的strem并对其执行终端操作时都使用Supplier.Get（），我仍然收到“流已被操作或关闭”异常。任何人都可以看看我的代码并建议我做错了吗？

引发异常的方法：

private static void printMyDetails(Supplier<Stream<Result>> mySupplier, String myStatus) {
        checkNotNull(mySupplier);
        checkArgument(isNotEmpty(myStatus), "Invalid My status");

        if (mySupplier.get().noneMatch(result -> true)) { //<-This is where the exception is thrown
            if (log.isInfoEnabled()) {
                log.info("Number of My with status '{}': {}", My, 0);
            }
        } else {
            log.info("Number of My with status '{}': {}", myStatus, mySupplier.get().count());
            log.info("Details of My(s) with status: '{}'", myStatus);
            mySupplier.get().sorted().forEach(Utils::printMyNameAndDetails);
        }
    }

正在调用上述方法的地方：

rb.keySet().stream().filter(key -> containsIgnoreCase(key, "status")).map(rb::getString)
                .filter(StringUtils::isNotEmpty).forEach(status -> {
            var resultsWithExpectedStatusSupplier = requireNonNull(getResultsWithExpectedStatusSupplier(results, status));
            resultsWithExpectedStatusSupplier.ifPresentOrElse(streamSupplier -> Stream.ofNullable(streamSupplier)
                    .forEach(safeStreamSupplier -> printMyDetails(safeStreamSupplier, status)), () -> {
                if (log.isInfoEnabled())
                    log.info("0 My with status: {}", status);
            });
        });

流提供者：

private static Optional<Supplier<Stream<Result>>> getResultsWithExpectedStatusSupplier(
            @NotNull List<Result> results, @NotNull String expectedStatus) {
        checkArgument(!results.isEmpty(), "Results list is empty");
        checkArgument(isNotEmpty(expectedStatus), "Invalid expected status");

        var resultStreamWithExpectedStatus = requireNonNull(results.stream().filter(result -> ofNullable(result).map(Result::getStatus)
                .allMatch(s -> isNotEmpty(s) && s.equalsIgnoreCase(expectedStatus))));
        return resultStreamWithExpectedStatus.count() == 0 ? Optional.empty() : Optional.of(() -> resultStreamWithExpectedStatus);
    }

Answer 1

您只能消费一次Stream。供应商似乎总是一次又一次地提供相同的流。在第一个终端操作之后，流被排干；供应商的信息流必须始终是新的信息流。