我想检测目录中的变化，所以我使用 WatchService 来实现

public class DirWatcher implements Runnable {

    private Path path;
    private ExecutorService exe;

    public DirWatcher(Path path, ExecutorService exe) {
        this.path = path;
        this.exe = exe;
    }

    public void start() throws Exception {
        WatchService watchService = FileSystems.getDefault().newWatchService();
        path.register(watchService, StandardWatchEventKinds.ENTRY_CREATE, StandardWatchEventKinds.ENTRY_DELETE, StandardWatchEventKinds.ENTRY_MODIFY);
        WatchKey key;
        while ((key = watchService.take()) != null) {
            for (WatchEvent<?> event : key.pollEvents()) {
                if(isFileEvent(event)) {
                    // do stuff with file
                } else if(isNewDirCreated(event)) {
                    Path dir = getPath(event, path);
                    DirWatcher newWatcher = new DirWatcher(dir, exe);
                    exe.execute(newWatcher);
                }
            }
            key.reset();
        }

        watchService.close();
    }

    public void run() {
        try {
            start();
        } catch(Exception e) {
        }
    }

    //Other methods
}

这是主要方法

public class DirectoryWatcherExample {

    public static void main(String[] args) throws Exception {
        Path root = getRootPath();
        ExecutorService exe = Executors.newFixedThreadPool(//HOW BIG THE POOL SHOULD I INIT? THE NUMBER OF DIRECTORIES IS LARGE (> 50000))
        DirWatcher watcher = new DirWatcher(root, exe);
        exe.execute(watcher);
        List<Path> paths = listRecrursive(root);
        paths.stream().map(p -> new DirWatcher(p, exe)).forEach(exe::execute);
    }
}

我的问题是：我应该如何初始化线程池？由于任务数量巨大（> 50000）。它会影响服务器（64 Gb RAM）吗？

ForkJoinPool 和 RecursiveTask 在这种情况下有用吗？如果是，你能提供伪代码吗？如果没有，是否有任何优化的解决方案？谢谢