java - 程序结束时关闭java执行器服务

Question

考虑以下代码:

public class ExchangeDataSimulatorStartup {

    public static ExecutorService executorService = Executors
            .newFixedThreadPool(Integer.parseInt(10);

public static void pullData() {


    boolean shutdown = false;

    while (!shutdown) {

        // create a list to hold the Future object associated with Callable
        List<Future<String>> futureList = new ArrayList<Future<String>>();

        while (stockSymbolsListItr.hasNext()) {
            PullStocksData pullStocksData = new PullStocksData(
                    stockSymbolsListItr.next());

            // submit Callable tasks to be executed by thread pool
            Future<String> future = executorService.submit(pullStocksData);

            // add Future to the list, we can get return value using Future
            futureList.add(future);
        }

    }
}

我需要执行程序服务在应用程序收到关闭信号时关闭。否则执行者应该继续运行。所以我在另一篇文章中看到了以下实现，它说我应该在我的主要功能中添加类似以下代码的内容:

try {

    // We will now start our ExchangeDataSimulator
        ExchangeDataSimulatorStartup.pullData();

 } catch (Exception ex) {

      // do some logging

 } finally {

   executorService.shutdown();

}

我相信上面的代码可以正常工作。它(在 main 方法的 finally block 中关闭执行程序)是正确的方法吗？对此有更好的方法吗？

Answer 1

通常我想给任务一个完成的机会，但时间不会太长。方法见下图:

/**
 * Shutdown the given executor service and wait for tasks to finish.
 * If tasks do not finish within the given time-out, the executor service is forcibly closed
 * (running tasks are interrupted) and tasks that never commenced execution are returned.  
 * @param es the executor service to shutdown
 * @param timeoutSeconds the maximum time in seconds to wait.
 * @return null on normal shutdown, else a list of tasks that never commenced execution
 */
public static List<Runnable> shutdown(ExecutorService es, int timeoutSeconds) {

    es.shutdown();
    if (timeoutSeconds > 0) {
        try {
            es.awaitTermination(timeoutSeconds, TimeUnit.SECONDS);
        } catch (InterruptedException e) {
            log.warn("Waiting for executor service tasks completion interrupted.", e);
        }
    }
    return (es.isTerminated() ? null : es.shutdownNow());
}