ExecutorService创建线程池后，我创建的线程是否会自动加入这个线程池

Question

        //线程池
        ExecutorService pool = Executors.newCachedThreadPool();

        //创建100个线程
        for(int i = 0; i < count; i++){
            MyThread target = new MyThread("para1", "para2", "para3", countDownLatch);

        }

 

如何查看我的线程池里有多少线程？

 

Answer 1

不会，你这个线程池是无参的，使用的是默认线程工厂，想要使用自己的线程的话，需要把线程放到线程工厂中。

public static ExecutorService newCachedThreadPool(ThreadFactory threadFactory) {
        return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
                                      60L, TimeUnit.SECONDS,
                                      new SynchronousQueue<Runnable>(),
                                      threadFactory);
    }

默认的线程工厂是这个：

 static class DefaultThreadFactory implements ThreadFactory {
        private static final AtomicInteger poolNumber = new AtomicInteger(1);
        private final ThreadGroup group;
        private final AtomicInteger threadNumber = new AtomicInteger(1);
        private final String namePrefix;

        DefaultThreadFactory() {
            SecurityManager s = System.getSecurityManager();
            group = (s != null) ? s.getThreadGroup() :
                                  Thread.currentThread().getThreadGroup();
            namePrefix = "pool-" +
                          poolNumber.getAndIncrement() +
                         "-thread-";
        }

        public Thread newThread(Runnable r) {
            Thread t = new Thread(group, r,
                                  namePrefix + threadNumber.getAndIncrement(),
                                  0);
            if (t.isDaemon())
                t.setDaemon(false);
            if (t.getPriority() != Thread.NORM_PRIORITY)
                t.setPriority(Thread.NORM_PRIORITY);
            return t;
        }
    }

也可以自己实现覆盖~

如果觉得回答对你有帮助的话，可采纳~~