java - 从外部中止 JUnit 线程

Question

我正在编写一个使用 JUnit 的测试应用程序。我们使用可运行类手动启动 JUnit

public class MyLauncher implements Runnable {

    public void run() {
        launchJunit();
    }

    private void launchJunit() {
        LauncherDiscoveryRequest request = LauncherDiscoveryRequestBuilder.request().selectors(selectors).build();
        Launcher launcher = LauncherFactory.create();
        launcher.execute(request);
    }
}

使用

public class MyApplication {

    public void main(String[] args) {
        ScheduledExecutorService pool = Executors.newScheduledThreadPool(1);
        ScheduledFuture<?> thread = null;
        thread = pool.schedule(new MyLauncher());

        //
        // do some magic
        //

        thread.cancel(true);
        // or
        pool.shutdownNow();
    }
}

但是，thread.cancel() 或 pool.shutdownNow() 都不会中断 JUnit 线程。除非我在应用程序末尾使用 System.exit(0)，否则 JUnit 将继续运行。有没有办法中断 JUnit 线程？我正在使用 JUnit 扩展，因此我可以在必要时 Hook 一些回调。

Answer 1

我已经尝试过了，对我来说，线程似乎被 pool.shutdownNow() 中断，但有一点延迟。

您可以使用方法https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ExecutorService.html#awaitTermination等待它终止。

当我像这样重新排列你的代码时:

public static void main(String[] args) throws InterruptedException {
        ScheduledExecutorService pool = Executors.newScheduledThreadPool(1);
        ScheduledFuture<?> thread = null;
        MyLauncher myLauncher = new MyLauncher();
        thread = pool.schedule(myLauncher, 0, TimeUnit.MILLISECONDS);

        Set<Thread> threadSet = Thread.getAllStackTraces().keySet();
        System.out.println("Number of threads: " + threadSet.size());


        thread.cancel(true);
        pool.shutdownNow();

        System.out.println("Waiting for thread to terminate...");
        pool.awaitTermination(10, TimeUnit.SECONDS);

        threadSet = Thread.getAllStackTraces().keySet();
        System.out.println("Number of threads: " + threadSet.size());
}

我得到输出:

Number of threads: 6
Waiting for thread to terminate...
Number of threads: 5