java - executorService 接口(interface)的 ShutdownNow 不会关闭正在进行的任务

Question

在第一个进程从 invokeAny 方法提供一些输出后，我立即使用 shutdownNow 关闭进程。但在输出中，即使在调用 shutdownNow() 之后，我也可以看到进程仍在完成流程中并完成其工作，然后才关闭。代码:

int numberOfRecordsInsertedSuccessfully = 0;
    List<String> userRecordList = readFile(
            "C:\\Users\\sonar\\git\\MultiThreading-Cocurrency\\JavaSEConcurrencyAPIStudyProject\\src\\main\\java\\Resources\\ExecutorServiceUserFile.txt");
    // ExecutorService executorService = Executors.newSingleThreadExecutor();  //Thread pool of single thread.
    // ExecutorService executorService = Executors.newFixedThreadPool(3); //Thread pool size is 3 here
    ExecutorService executorService = Executors.newCachedThreadPool();
    UserDao userDao = new UserDao();

    List<Callable<Integer>> listOfCallable= new ArrayList<>();
    userRecordList.forEach(x -> listOfCallable.add(new UserProcessor(x, userDao)));

    try {
        Integer future = executorService.invokeAny(listOfCallable);
        System.out.println(future);
    } catch (InterruptedException | ExecutionException e) {
        e.printStackTrace();
    }
    System.out.println(executorService.shutdownNow());
    System.out.println("ExecutorService is shutting down " + executorService.isShutdown()); //After getting first future result this statement will be executed.
    System.out.println("ExecutorService is Terminated " + executorService.isTerminated());

控制台输出为:

有关代码的更多详细信息，请参阅上面的 git 链接

类:ExecutorServiceThreeTypesOfShutDownMethodMainClass

包:com.Concurrency.JavaSEConcurrencyAPIStudyProject.HighLevelApis.ExecutorServiceInterface

要使用的项目:JavaSEConcurrencyAPIStudyProject

git链接:Git link for project for more details

请帮忙，为什么会出现这种情况？我该如何解决这个问题？

Answer 1

该方法的 Javadoc 内容如下:

除了尽最大努力尝试停止处理主动执行的任务之外，没有任何保证。例如，典型的实现将通过 Thread.interrupt() 取消，因此任何无法响应中断的任务可能永远不会终止。

https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ExecutorService.html

因此，如果您的任务不检查中断标志并捕获并忽略 InterruptedException，那么 shutdownNow() 将无法停止它们