Executors类
+ newFixedThreadPool(int nThreads): static ExecutorService+ newSingleThreadExecutor(int nThreads):static ExecutorService+ newCachedThreadPool(): static ExecutorService+ newSingleThreadScheduledExecutor(): static ScheduledExecutorService
Executor 接口
+ execute(Runnable command):void
AbstractExecutorService抽象类
+ submit(Runnable task):Future
ThreadPoolExecutor类
+核心的几个构造方法
ExecutorService 接口
+ shutdown():void+ shutdownNow():List+ submit(Runnable task):Future+ isShutdown():boolean+ isTerminated():boolean