线程池

public ThreadPoolExecutor(int corePoolSize,
                          int maximumPoolSize,
                          long keepAliveTime,
                          TimeUnit unit,
                          BlockingQueue<Runnable> workQueue) {
    this(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue,
         Executors.defaultThreadFactory(), defaultHandler);
}

int corePoolSize：核心线程数

int maximumPoolSize：最大线程数

long keepAliveTime：线程空闲时间

TimeUnit unit：

BlockingQueue<Runnable> workQueue：任务队列容量（阻塞队列）

https://www.cnblogs.com/dolphin0520/p/3932921.html