package com.test.utils.files;

import com.sun.deploy.util.SyncFileAccess;

import org.apache.commons.io.monitor.FileAlterationListenerAdaptor;

import org.apache.commons.io.monitor.FileAlterationMonitor;

import org.apache.commons.io.monitor.FileAlterationObserver;

import java.io.File;

public class FolderWatcher extends FileAlterationListenerAdaptor {

    FileAlterationMonitor monitor;

    public FolderWatcher(String directory) {

        monitor = new FileAlterationMonitor(500);

        FileAlterationObserver fileObserver = new FileAlterationObserver(directory);

        fileObserver.addListener(this);

        monitor.addObserver(fileObserver);

    }

    public void start(boolean isDaemonThread) throws Exception {

        if (isDaemonThread) {

            monitor.setThreadFactory(r -> {

                Thread th = new Thread(r);

                th.setDaemon(true);

                return th;

            });

        }

        monitor.start();

    }

    @Override

    public void onFileChange(File file) {

        System.out.println("change" + file);

    }

    @Override

    public void onFileCreate(File file) {

        while (true) {

            try {

                SyncFileAccess fileAccess = new SyncFileAccess(file);

                SyncFileAccess.FileInputStreamLock lock = fileAccess.openLockFileInputStream(1000, false);lock.getFileInputStream().close();

　　　　　　　　　　lock.release();
　　　　　　　　　　 break; 
　　　　　　　　} catch (Exception e)
　　　　　　 { try { Thread.sleep(100); } catch (InterruptedException ignored) { } } } System.out.println("create:" + file); } }

package com.test.utils.files;

import java.io.IOException;

import java.nio.file.*;

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

public class FolderWatcher2 {

    private WatchService watcher;

    public FolderWatcher2(String directory) throws IOException {

        watcher = FileSystems.getDefault().newWatchService();

        Path path = Paths.get(directory);

        path.register(watcher, ENTRY_CREATE, ENTRY_MODIFY);

        Path path1 = Paths.get(directory, "abc");

        path1.register(watcher, ENTRY_CREATE, ENTRY_MODIFY);

    }

    public void start() throws InterruptedException {

        while (true) {

            WatchKey key = watcher.take();

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

                WatchEvent.Kind<?> kind = event.kind();

                if (kind == OVERFLOW) {//事件可能lost or discarded

                    continue;

                }

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

                System.out.printf("Event %s has happened,which fileName is %s%n", kind.name(), fileName);

            }

            //这行必须有，不然不能连续地监控目录

            if (!key.reset()) {

                break;

            }

        }

    }

}