类继承结构

线程池创建

• Executors

ExecutorService service = Executors.newFixedThreadPool(int nThreads);
ExecutorCompletionService completionService = new ExecutorCompletionService(service);
service.submit(...);
service.execute(...);

ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();

• ThreadPoolExecutor

ThreadPoolExecutor executor = new ThreadPoolExecutor(int corePoolSize, int maximumPoolSize,  long keepAliveTime, TimeUnit unit,  BlockingQueue<Runnable> workQueue);
ThreadPoolExecutor executor = new ThreadPoolExecutor(int corePoolSize, int maximumPoolSize,  long keepAliveTime, TimeUnit unit,  BlockingQueue<Runnable> workQueue, ThreadFactory threadFactory);
ThreadPoolExecutor executor = new ThreadPoolExecutor(int corePoolSize, int maximumPoolSize,  long keepAliveTime, TimeUnit unit,  BlockingQueue<Runnable> workQueue, ThreadFactory threadFactory, RejectedExecutionHandler handler);

• ScheduledThreadPoolExecutor

ScheduledThreadPoolExecutor scheduledThreadPoolExecutor = new ScheduledThreadPoolExecutor(int corePoolSize);
ScheduledThreadPoolExecutor scheduledThreadPoolExecutor = new ScheduledThreadPoolExecutor(int corePoolSize, ThreadFactory threadFactory);
ScheduledThreadPoolExecutor scheduledThreadPoolExecutor = new ScheduledThreadPoolExecutor(int corePoolSize, RejectedExecutionHandler handler);
ScheduledThreadPoolExecutor scheduledThreadPoolExecutor = new ScheduledThreadPoolExecutor(int corePoolSize, ThreadFactory threadFactory, RejectedExecutionHandler handler);

Runnable 和 Callable

public interface Callable<V> {
    V call() throws Exception;
}

public interface Runnable {
    public abstract void run();
}

• 区别：
  a. Callable接口的call()方法可以有返回值（返回值通过Future接口获取），而Runnable接口的run()方法没有返回值。
  b. Callable接口的call()方法可以声明抛出异常，而Runnable接口的run()方法不可以。