import hudson.util.DaemonThreadFactory; //导入依赖的package包/类
public HealthChecksThreadPool(HealthCheckRegistry healthCheckRegistry) {
    super(MAX_THREAD_POOL_SIZE, MAX_THREAD_POOL_SIZE, 5L, TimeUnit.SECONDS,
            new LinkedBlockingQueue<Runnable>(), //
            new ExceptionCatchingThreadFactory(new DaemonThreadFactory(new ThreadFactory() {
                private final AtomicInteger number = new AtomicInteger();

                public Thread newThread(Runnable r) {
                    return new Thread(r, "Metrics-HealthChecks-" + number.incrementAndGet());
                }
            })), new MetricsRejectedExecutionHandler(healthCheckRegistry));
    this.allowCoreThreadTimeOut(true); // allow stopping all threads if idle
    this.healthCheckRegistry = healthCheckRegistry;
    LOGGER.log(Level.FINE,
            "Created thread pool with a max of {0} threads (plus {1} in queue) for {2} health checks",
            new Object[] { getMaximumPoolSize(),
                           Math.max(0, healthCheckRegistry.getNames().size() + 1 - getMaximumPoolSize()),
                           healthCheckRegistry.getNames().size() });
}