可调用任务未正确执行

Question

您好，我创建了一个简单的任务，它正在访问一个第三方 API，

我尝试创建一个可调用任务并与 ExecutorService

并行执行

       for (String script : allScripts) {
            callableTasks.add(new DataFetchTask(script,TimeInterval.get(interval),
                    Range.get(range)).newCallable());
        }
        final ExecutorService executorService = new ThreadPoolExecutor(1, 10,
                10000, TimeUnit.MILLISECONDS,
                new SynchronousQueue<Runnable>());
        try {
            System.out.println("Callable Tasks"+callableTasks.size());
            final Future<YahooFinResponse> yahooFinResponseFuture = executorService.submit(callableTasks.get(0));
            /*final List<Future<YahooFinResponse>> futures = executorService.invokeAll(callableTasks);
            for(Future<YahooFinResponse> future : futures) {
                yahooFinResponses.add(future.get());
            }*/
            return FinDataServiceUtil.writeResponsesToCSVFile(yahooFinResponses);
        } catch (Exception e) {
            e.printStackTrace();
        }

任务Class

@RequiredArgsConstructor
public class DataFetchTask {

    private final String script;
    private final TimeInterval timeInterval;
    private final Range timeRange;

    @Autowired
    YahooFinDataFetcher yahooFinDataFetcher;

    public Callable<YahooFinResponse> newCallable() {

        return new Callable<YahooFinResponse>() {

            public YahooFinResponse call() {
                System.out.println("Starting Job for Script"+script);
                try {
                    Thread.sleep(5000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println("After wait");
                final YahooFinResponse yahooFinResponse = yahooFinDataFetcher.fetchData(script +
                        ".NS", timeInterval, timeRange);
                System.out.println("Returning from call"+yahooFinResponse.chart.error);
                return yahooFinResponse;
            }
        };
    }

}

服务class

@Component
public class YahooFinDataFetcher {

    private static final OkHttpClient client = new OkHttpClient();
    private static final Gson gson = new Gson();

    private static final String BASE_URL = "***;
    private static final String DOMAIN = "**";
    private static final String CORS_DOMAIN = "***";

    public YahooFinResponse fetchData (final String scriptName, final TimeInterval timeInterval,
            final Range range) {
        System.out.println("Calling Service");
        final Request request = new Request.Builder()
                .url(createUrl(scriptName, timeInterval, range))
                .build();

        final Call call = client.newCall(request);
        try {
            final Response response = call.execute();
            final String responseStr = response.body().string();
            final YahooFinResponse yahooFinResponse = gson.fromJson(responseStr,
                    YahooFinResponse.class);
            System.out.println(String.format("Returning Data For YahooFInResponse %s "
                    + "\n",yahooFinResponse));
            return yahooFinResponse;
        } catch (IOException e) {
            e.printStackTrace();
        }
        System.out.println(String.format("Returning null from fetchData for %s  TimeInterval %s, "
                + "Range %s \n",scriptName,timeInterval,range));
        return null;
    }

我得到的输出为

Size5list[RELIANCE, SBIN, YESBANK, ITC, VEDL]
Callable Tasks5
Starting Job for ScriptRELIANCE
After wait

但没有得到作业完成的输出，

我尝试减少作业大小，将 ExecutorService 的创建更改为 FixedThreadPool 和 CachedThreadPool

将 DataFetchTask 更改为 newCallable 作为方法，而早些时候这个 class 本身正在直接实现 Callable<T>

当我尝试获取 future.get() 时，它给出 NullPointerException

我尝试了多种方法，但不确定 Callable 任务创建有什么问题。

我正在通过控制器点击服务

Answer 1

您的 yahooFinDataFetcher 可能为空，因为 IOC 无法注入它的实例。 DataFetchTask 未作为组件处理。

尝试在 DataFetchTask 中手动实例化 yahooFinDataFetcher，看看是否真的如此


@RequiredArgsConstructor
public class DataFetchTask {

    private final String script;
    private final TimeInterval timeInterval;
    private final Range timeRange;

    @Autowired
    YahooFinDataFetcher yahooFinDataFetcher = new YahooFinDataFetcher();

   ...

可调用任务未正确执行

Callable Task is not executing properly

java

multithreading

thread-safety

executorservice