文件在Java中更改了监听器

import java.io.IOException;
import java.nio.file.*;
import static java.nio.file.StandardWatchEventKinds.*;

public class WatchDir {

    public static void main(String[] args) throws IOException {

        Path dir = Paths.get("/path/to/directory");
        try (WatchService watcher = FileSystems.getDefault().newWatchService()) {
            WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);

            while (true) {
                WatchKey k = watcher.take();

                for (WatchEvent<?> event : k.pollEvents()) {
                    WatchEvent.Kind<?> kind = event.kind();

                    if (kind == OVERFLOW) {
                        continue;
                    }

                    WatchEvent<Path> ev = (WatchEvent<Path>) event;
                    Path filename = ev.context();

                    System.out.println(kind + " - " + filename);
                }

                boolean valid = k.reset();
                if (!valid) {
                    break;
                }
            }
        }
    }
}