【并发编程】- 线程池使用shutdownNow()方法中断任务

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使用shutdownNow()方法实现代码如下：

public class ShutdownRun {
    public static void main(String[] args) {
        SecondRunnable secondRunnable = new SecondRunnable();
        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(2, 6, 0, TimeUnit.SECONDS,new LinkedBlockingQueue<>());
        for (int i = 0; i < 4; i++) {
            threadPoolExecutor.execute(secondRunnable);
        }
        threadPoolExecutor.shutdownNow();
    }
}

运行结果如下：

任务没有完成，就被中断了！
任务没有完成，就被中断了！
进入catch中断了任务
进入catch中断了任务
java.lang.InterruptedException
	at com.ozx.concurrentprogram.executor.service.SecondRunnable.run(SecondRunnable.java:17)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
java.lang.InterruptedException
	at com.ozx.concurrentprogram.executor.service.SecondRunnable.run(SecondRunnable.java:17)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

从运行结果看出剩下的2个任务被取消，没有被运行。

修改代码如下：

public class SecondRunnable implements Runnable {


    @Override
    public void run() {
        for (int i = 0; i < Integer.MAX_VALUE / 1000; i++) {
            Math.random();
            Math.random();
            Math.random();
            Math.random();
        }
        System.out.println("任务成功完成！");
    }
}

运行类代码如下：

public class ShutdownRun {
    public static void main(String[] args) {
        SecondRunnable secondRunnable = new SecondRunnable();
        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(2, 6, 999, TimeUnit.SECONDS,new LinkedBlockingQueue<>());
        for (int i = 0; i < 4; i++) {
            threadPoolExecutor.execute(secondRunnable);
        }
        try {
            Thread.sleep(1000);
            threadPoolExecutor.shutdownNow();
            System.out.println("main 结束");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

运行结果如下：

main 结束
任务成功完成！
任务成功完成！

从运行结果看出2个任务被成功执行，其他2个任务被取消运行，并且进程销毁。

修改运行类代码如下：

public class ShutdownRun {
    public static void main(String[] args) {
        SecondRunnable secondRunnable = new SecondRunnable();
        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(2, 6, 999, TimeUnit.SECONDS,new LinkedBlockingQueue<>());
        for (int i = 0; i < 4; i++) {
            threadPoolExecutor.execute(secondRunnable);
        }
        try {
            Thread.sleep(1000);
            threadPoolExecutor.shutdownNow();
            threadPoolExecutor.execute(secondRunnable);
            System.out.println("main 结束");
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

运行结果如下：

Exception in thread "main" java.util.concurrent.RejectedExecutionException: Task com.ozx.concurrentprogram.executor.service.SecondRunnable@2280cdac rejected from java.util.concurrent.ThreadPoolExecutor@1517365b[Shutting down, pool size = 2, active threads = 2, queued tasks = 0, completed tasks = 0]
	at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2063)
	at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:830)
	at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1379)
	at com.ozx.concurrentprogram.executor.controller.ShutdownRun.main(ShutdownRun.java:26)
任务成功完成！
任务成功完成！

2个任务被成功执行，其余2个任务被取消执行，而最后一个任务则拒绝执行，运行效果即抛出异常，并且在最后进程销毁。