线程池中线程异常后：销毁还是复用？

前言

下面测试是使用的JUC包下的 java.util.concurrent.ThreadPoolExecutor，本文将围绕验证，阅读源码俩方面来解析这个问题。这里使用两种提交方式分别验证，两种提交方式不一样结果也不一样！如果连这个都不知道，别跟我说你用过线程池好吗？如果线上出bug异常被吞掉，不知道怎么排查你就老实了。。

1.验证execute提交线程池中

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().setNamePrefix("test-").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);
        }
    }
}

运行后发现，test-2的线程不见了，多出来一个test-3线程

2025-09-22T05:40:47.png

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.验证submit提交线程池中

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"));
}

运行结果，把异常吞掉了，外面一点感知都没没有！并且线程也继续复用了，这要是出bug了得排查多久？

2025-09-22T05:40:57.png