使用WatchService监视主用户目录上文件的创建、删除或修改

import java.nio.file.*;

import java.util.Properties;

/*
N o w J a v a . c o m - 时代Java 提供
*/



public class WatchServiceExample {


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

        FileSystem fs = FileSystems.getDefault();

        WatchService ws = fs.newWatchService();


        Properties props = System.getProperties();

        String homePath = props.get("user.home").toString();

        Path home = fs.getPath(homePath);


        home.register(ws, StandardWatchEventKinds.ENTRY_CREATE, StandardWatchEventKinds.ENTRY_DELETE,

                StandardWatchEventKinds.ENTRY_MODIFY, StandardWatchEventKinds.OVERFLOW);
                /* from 
                时   代     Java  公  众  号 - nowjava.com*/


        System.out.println("Monitoring file creation in " + home + "... (Ctrl+C to quit)");

        while (true) {

            WatchKey key = ws.take();

            for (WatchEvent<?> event : key.pollEvents()) {

                if (event.kind() == StandardWatchEventKinds.ENTRY_CREATE) {

                    Path item = (Path)event.context();

                    System.out.println("Created: " + item);

                } else if (event.kind() == StandardWatchEventKinds.ENTRY_DELETE) {

                    Path item = (Path)event.context();

                    System.out.println("Removed: " + item);

                } else if (event.kind() == StandardWatchEventKinds.ENTRY_MODIFY) {

                    Path item = (Path)event.c