Executors创建单个线程池为什么出现两个线程池

Question

@Componentpublic class StatusListener implements ServletContextAware { final ReentrantLock lock = new ReentrantLock(); @Override public void setServletContext(ServletContext servletContext) { Runnable runnable = new Runnable() { public void run() { statusTask(); } }; ScheduledExecutorService service = Executors.newSingleThreadScheduledExecutor(); // 第二个参数为首次执行的延时时间，第三个参数为定时执行的间隔时间 service.scheduleAtFixedRate(runnable, 20, 60, TimeUnit.SECONDS); } public void statusTask() { final ReentrantLock lock = this.lock; lock.lock(); try { System.out.println(Thread.currentThread().getName()); System.out.println(Thread.currentThread().getId()); } catch (Exception e) { e.printStackTrace(); } finally { lock.unlock(); } } } 运行结果为：pool-2-thread-140 pool-4-thread-142