# Java實戰系列 - 線程池中的線程出現異常

問題：線程池中的線程執行任務出現異常，該線程接下來的命運如何？

結論：線程會結束，線程池會新建線程替換該線程

驗證：編碼驗證，代碼如下

public class ThreadPoolExceptionTest {

    // 創建一個核心線程數、最大線程數都爲1的線程池，任務隊列最大容量爲10
    private static ThreadPoolExecutor executor = new ThreadPoolExecutor(1, 1,
            0L, TimeUnit.SECONDS,
            new ArrayBlockingQueue<>(10),
            new java.util.concurrent.ThreadPoolExecutor.DiscardPolicy());

    public static void main(String[] args) {

        executor.execute(() -> System.out.println(Thread.currentThread().getName() + " " + (1 / 0)));
        try {
            // 睡眠1秒，讓打印結果更明顯
            Thread.sleep(1000L);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        executor.execute(() -> System.out.println(Thread.currentThread().getName() + " " + (1 / 1)));
        executor.execute(() -> System.out.println(Thread.currentThread().getName() + " " + (1 / 2)));
        executor.execute(() -> System.out.println(Thread.currentThread().getName() + " " + (1 / 3)));
        executor.execute(() -> System.out.println(Thread.currentThread().getName() + " " + (1 / 4)));

    }
}

• 打印日誌如下：

Exception in thread "pool-1-thread-1" java.lang.ArithmeticException: / by zero
    at com.lushwe.thread.ThreadPoolExceptionTest.lambda$main$0(ThreadPoolExceptionTest.java:25)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
pool-1-thread-2 1
pool-1-thread-2 0
pool-1-thread-2 0
pool-1-thread-2 0

• 總結：通過日誌線程的線程名稱可知，線程執行任務出現異常，該線程會結束，線程池會創建新的線程替換該線程執行其他任務。

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本文完。