newSingleThreadExecutor和newFixedThreadPool（1）之间的区别

Question

在内部，newSingleThreadExecutor()和newFixedThreadPool()创建ThreadPoolExecutor对象，然后newSingleThreadExecutor()和newFixedThreadPool(1)有什么区别？为什么Java有这些方法？

newFixedThreadPoo

 public static ExecutorService newFixedThreadPool(int nThreads) {
        return new ThreadPoolExecutor(nThreads, nThreads,
                                      0L, TimeUnit.MILLISECONDS,
                                      new LinkedBlockingQueue<Runnable>());
    }

newSingleThreadExecutor

public static ExecutorService newSingleThreadExecutor() {
        return new FinalizableDelegatedExecutorService
            (new ThreadPoolExecutor(1, 1,
                                    0L, TimeUnit.MILLISECONDS,
                                    new LinkedBlockingQueue<Runnable>()));
    }