Watching A Directory For Change

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

public class ListenDirectory {
    public static void main(String[] args) {
        Path path = Paths.get(args[0]);
        WatchService watchService = null;
        try {
            watchService = path.getFileSystem().newWatchService();
            path.register(watchService,
StandardWatchEventKinds.ENTRY_MODIFY,
                              StandardWatchEventKinds.ENTRY_DELETE,
                              StandardWatchEventKinds.ENTRY_CREATE);
        } catch (IOException e) {
            e.printStackTrace();
        }
       
        WatchKey key = null;
        try{
            //infinite loop
            while((key = watchService.take())!=null){// blocks until a key is available
               
               
                // iterate for each event
                for(WatchEvent<?> event:key.pollEvents()){
                    switch(event.kind().name()){
                        case "OVERFLOW":
                            System.out.println("Indicates that events might have been lost or discarded. It is not necessary to register for the OVERFLOW event to receive it.");
                        break;
                        case "ENTRY_MODIFY":
                            System.out.println("File " + event.context() + " is changed!");
                            break;
                        case "ENTRY_CREATE":
                            System.out.println("File " + event.context() + " is created!");
                            break;
                        case "ENTRY_DELETE":
                            System.out.println("File " + event.context() + " is deleted!");
                            break;
                    }
                }
                //resetting the key is important to receive subsequent notifications
                key.reset();
            }
        }catch(InterruptedException e){return;}
    }
}