“线程池中线程异常后：销毁还是复用？”

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线程异常后，线程池会如何处理？

在今年的敏捷团队建设中，我通过Suite执行器实现了一键自动化单元测试。Juint除了Suite执行器还有哪些执行器呢？由此我的Runner探索之旅开始了！

需要说明，本文的线程池都是java.util.concurrent.ExecutorService线程池，本文将围绕验证，阅读源码俩方面来解析这个问题。

代码验证

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2.1 验证execute提交线程池中

2.1.1 测试代码：

public class ThreadPoolExecutorDeadTest {
    public static void main(String[] args) throws InterruptedException {        ExecutorService executorService = buildThreadPoolExecutor();        executorService.execute(() -> exeTask("execute"));        executorService.execute(() -> exeTask("execute"));        executorService.execute(() -> exeTask("execute-exception"));        executorService.execute(() -> exeTask("execute"));        executorService.execute(() -> exeTask("execute"));

        Thread.sleep(5000);        System.out.println("再次执行任务=======================");
        executorService.execute(() -> exeTask("execute"));        executorService.execute(() -> exeTask("execute"));        executorService.execute(() -> exeTask("execute"));        executorService.execute(() -> exeTask("execute"));        executorService.execute(() -> exeTask("execute"));    }

    public static ExecutorService buildThreadPoolExecutor() {        return new ThreadPoolExecutor(5, 10, 30, TimeUnit.SECONDS,                new LinkedBlockingQueue<>(1000), new ThreadFactoryBuilder().setNameFormat("test-%s").build()                , new ThreadPoolExecutor.CallerRunsPolicy());    }
    private static void exeTask(String name) {        String printStr = "[thread-name:" + Thread.currentThread().getName() + ",执行方式:" + name + "]";        if ("execute-exception".equals(name)) {            throw new RuntimeException(printStr + ", 我抛异常了");        } else {            System.out.println(printStr);        }    }}

2.1.2 执行结果如下：

2.1.3 结论：

execute 提交到线程池的方式，如果执行中抛出异常，并且没有在执行逻辑中catch，那么会抛出异常，并且移除抛出异常的线程，创建新的线程放入到线程池中。

2.2 验证submit提交线程池中

2.2.1 测试代码：

public class ThreadPoolExecutorDeadTest {
    public static void main(String[] args) throws InterruptedException {        ExecutorService executorService = buildThreadPoolExecutor();        executorService.submit(() -> exeTask("execute"));        executorService.submit(() -> exeTask("execute"));        executorService.submit(() -> exeTask("execute-exception"));        executorService.submit(() -> exeTask("execute"));        executorService.submit(() -> exeTask("execute"));

        Thread.sleep(5000);        System.out.println("再次执行任务=======================");
        executorService.submit(() -> exeTask("execute"));        executorService.submit(() -> exeTask("execute"));        executorService.submit(() -> exeTask("execute"));        executorService.submit(() -> exeTask("execute"));        executorService.submit(() -> exeTask("execute"));    }

    public static ExecutorService buildThreadPoolExecutor() {        return new ThreadPoolExecutor(5, 10, 30, TimeUnit.SECONDS,                new LinkedBlockingQueue<>(1000), new ThreadFactoryBuilder().setNameFormat("test-%s").build()                , new ThreadPoolExecutor.CallerRunsPolicy());    }
    private static void exeTask(String name) {        String printStr = "[thread-name:" + Thread.currentThread().getName() + ",执行方式:" + name + "]";        if ("execute-exception".equals(name)) {            throw new RuntimeException(printStr + ", 我抛异常了");        } else {            System.out.println(printStr);        }    }}