java.nio.file.WatchEvent.Kind Java Examples

public static void main(String[] args) throws IOException {
	FileListener listener = new FileListener() {
		@Override
		public void onEvent(String rootPath, WatchEvent<Path> event) {
			Kind<Path> kind = event.kind();
			String fileName = event.context().getFileName().toString();
			if (kind == StandardWatchEventKinds.ENTRY_MODIFY) {
				System.err.println(rootPath +"/"+fileName +"   "+ event.kind().name());
			}
		}

		@Override
		public Kind<?>[] events() {
			return new Kind<?>[] { StandardWatchEventKinds.ENTRY_MODIFY };
		}
	};

	ResourceListener.addListener("E:/jPersist2", listener);
	ResourceListener.addListener("E:/MyDownloads/Download", listener);
}
 

@Override
public void handleFileChanged(Kind<?> operation, String fileAbsolutePathname) {
	if (StandardWatchEventKinds.ENTRY_CREATE.equals(operation)) {
		DecryptedFile recentlyRemovedEntry = recentlyRemoved.getIfPresent(fileAbsolutePathname);
		if (recentlyRemovedEntry != null) {
			addOrUpdate(recentlyRemovedEntry);
		}
		return;
	}

	if (StandardWatchEventKinds.ENTRY_DELETE.equals(operation)) {
		remove(fileAbsolutePathname);
		return;
	}

	// Other cases not supported -- not needed
}
 

private void registerWithSubDirectories(AbstractWatchService watchService, Path toWatch) throws IOException {
    Files.walkFileTree(toWatch, EnumSet.of(FileVisitOption.FOLLOW_LINKS), Integer.MAX_VALUE,
            new SimpleFileVisitor<Path>() {
                @Override
                public FileVisitResult preVisitDirectory(Path subDir, BasicFileAttributes attrs)
                        throws IOException {
                    Kind<?>[] kinds = watchService.getWatchEventKinds(subDir);
                    if (kinds != null) {
                        registerDirectoryInternal(watchService, kinds, subDir);
                    }
                    return FileVisitResult.CONTINUE;
                }

                @Override
                public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
                    if (exc instanceof AccessDeniedException) {
                        logger.warn("Access to folder '{}' was denied, therefore skipping it.",
                                file.toAbsolutePath().toString());
                    }
                    return FileVisitResult.SKIP_SUBTREE;
                }
            });
}
 

@Override
protected void processWatchEvent(WatchEvent<?> event, Kind<?> kind, Path path) {
    if (kind == ENTRY_CREATE || kind == ENTRY_MODIFY) {
        File f = path.toFile();
        if (!f.isHidden() && f.getName().endsWith(".cfg")) {
            configDispatcher.processConfigFile(f);
        }
    } else if (kind == ENTRY_DELETE) {
        // Detect if a service specific configuration file was removed. We want to
        // notify the service in this case with an updated empty configuration.
        File configFile = path.toFile();
        if (configFile.isHidden() || configFile.isDirectory() || !configFile.getName().endsWith(".cfg")) {
            return;
        }
        configDispatcher.fileRemoved(configFile.getAbsolutePath());
    }
}
 

@Override
protected void processWatchEvent(WatchEvent<?> event, Kind<?> kind, Path path) {
    File file = path.toFile();
    if (!file.isHidden()) {
        try {
            URL fileUrl = file.toURI().toURL();
            if (ENTRY_DELETE.equals(kind)) {
                removeFile(fileUrl);
            }

            if (file.canRead() && (ENTRY_CREATE.equals(kind) || ENTRY_MODIFY.equals(kind))) {
                importFile(fileUrl);
            }
        } catch (MalformedURLException e) {
            logger.error("malformed", e);
        }
    }
}
 

private void fullEventAssertionsByKind(String fileName, Kind<?> kind, boolean osSpecific) throws Exception {
    waitForAssert(() -> assertThat(watchService.allFullEvents.size() >= 1, is(true)), DFL_TIMEOUT * 2,
            DFL_SLEEP_TIME);

    if (osSpecific && ENTRY_DELETE.equals(kind)) {
        // There is possibility that one more modify event is triggered on some OS
        // so sleep a bit extra time
        Thread.sleep(500);
        cleanUpOsSpecificModifyEvent();
    }

    assertEventCount(1);
    FullEvent fullEvent = watchService.allFullEvents.get(0);

    assertThat(fullEvent.eventPath.toString(), is(WATCHED_DIRECTORY + File.separatorChar + fileName));
    assertThat(fullEvent.eventKind, is(kind));
    assertThat(fullEvent.watchEvent.count() >= 1, is(true));
    assertThat(fullEvent.watchEvent.kind(), is(fullEvent.eventKind));
    String fileNameOnly = fileName.contains(File.separatorChar + "")
            ? fileName.substring(fileName.lastIndexOf(File.separatorChar) + 1, fileName.length())
            : fileName;
    assertThat(fullEvent.watchEvent.context().toString(), is(fileNameOnly));

    // Clear all the asserted events
    watchService.allFullEvents.clear();
}
 

private void processEvent(Path dir, WatchEvent<Path> event) {
    // Context for directory entry event is the file name of entry
    Path relChild = event.context();
    Path child = dir.resolve(relChild);

    Kind<Path> kind = event.kind();

    if(kind == ENTRY_MODIFY) {
        handleModification(child, externalInitiator);
    } else if(kind == ENTRY_CREATE) {
        handleCreation(child, externalInitiator);
    } else if(kind == ENTRY_DELETE) {
        model.delete(child, externalInitiator);
    } else {
        throw new AssertionError("unreachable code");
    }
}
 

@Override
protected void processWatchEvent(WatchEvent<?> event, Kind<?> kind, Path path) {
    if (kind == ENTRY_CREATE || kind == ENTRY_MODIFY) {
        File f = path.toFile();
        if (!f.isHidden() && f.getName().endsWith(".cfg")) {
            configDispatcher.processConfigFile(f);
        }
    } else if (kind == ENTRY_DELETE) {
        // Detect if a service specific configuration file was removed. We want to
        // notify the service in this case with an updated empty configuration.
        File configFile = path.toFile();
        if (configFile.isHidden() || configFile.isDirectory() || !configFile.getName().endsWith(".cfg")) {
            return;
        }
        configDispatcher.fileRemoved(configFile.getAbsolutePath());
    }
}
 

private void fullEventAssertionsByKind(String fileName, Kind<?> kind, boolean osSpecific) throws Exception {
    waitForAssert(() -> assertThat(watchService.allFullEvents.size() >= 1, is(true)), DFL_TIMEOUT * 2,
            DFL_SLEEP_TIME);

    if (osSpecific && kind.equals(ENTRY_DELETE)) {
        // There is possibility that one more modify event is triggered on some OS
        // so sleep a bit extra time
        Thread.sleep(500);
        cleanUpOsSpecificModifyEvent();
    }

    assertEventCount(1);
    FullEvent fullEvent = watchService.allFullEvents.get(0);

    assertThat(fullEvent.eventPath.toString(), is(WATCHED_DIRECTORY + File.separatorChar + fileName));
    assertThat(fullEvent.eventKind, is(kind));
    assertThat(fullEvent.watchEvent.count() >= 1, is(true));
    assertThat(fullEvent.watchEvent.kind(), is(fullEvent.eventKind));
    String fileNameOnly = fileName.contains(File.separatorChar + "")
            ? fileName.substring(fileName.lastIndexOf(File.separatorChar) + 1, fileName.length())
            : fileName;
    assertThat(fullEvent.watchEvent.context().toString(), is(fileNameOnly));

    // Clear all the asserted events
    watchService.allFullEvents.clear();
}
 

private void registerWithSubDirectories(AbstractWatchService watchService, Path toWatch) throws IOException {
    Files.walkFileTree(toWatch, EnumSet.of(FileVisitOption.FOLLOW_LINKS), Integer.MAX_VALUE,
            new SimpleFileVisitor<Path>() {
                @Override
                public FileVisitResult preVisitDirectory(Path subDir, BasicFileAttributes attrs)
                        throws IOException {
                    Kind<?>[] kinds = watchService.getWatchEventKinds(subDir);
                    if (kinds != null) {
                        registerDirectoryInternal(watchService, kinds, subDir);
                    }
                    return FileVisitResult.CONTINUE;
                }

                @Override
                public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
                    if (exc instanceof AccessDeniedException) {
                        logger.warn("Access to folder '{}' was denied, therefore skipping it.",
                                file.toAbsolutePath().toString());
                    }
                    return FileVisitResult.SKIP_SUBTREE;
                }
            });
}
 

@SuppressWarnings("unchecked")
@Override
protected void processWatchEvent(WatchEvent<?> event, Kind<?> kind, Path path) {
    logger.debug("New watch event {} for path {}.", kind, path);

    if (kind == OVERFLOW) {
        return;
    }

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

    logger.debug("Reloading javascript file {}.", filename);

    manager.removeFromCache(filename.toString());
}
 

/**
 * Precondition: Event and child must not be null.
 * @param kind type of the event (create, modify, ...)
 * @param source Identifies the related file.
 */
private void handleEvent(Kind<Path> kind, Path source) {
	try {
		if(PathUtils.isFileHidden(source)){
			return;
		}
		if (kind.equals(ENTRY_CREATE)) {
			addNotifyEvent(new NotifyFileCreated(source));
		} else if (kind.equals(ENTRY_MODIFY)) {
			addNotifyEvent(new NotifyFileModified(source));
		} else if (kind.equals(ENTRY_DELETE)) {
			addNotifyEvent(new NotifyFileDeleted(source));
		} else if (kind.equals(OVERFLOW)) {
			// error - overflow... should not happen here (continue if such an event occurs).
			// handled already
			logger.warn("Overflow event from watch service. Too many events?");
		} else {
			logger.warn("Unknown event received");
		}
	} catch (InterruptedException iex) {
		// put into queue failed
		logger.info("Handling event interrupted.", iex);
	}
}
 

private void processKey(WatchKey key) throws IOException {
    Path watchDir = (Path) key.watchable();
    for (WatchEvent<?> event : key.pollEvents()) {
        Kind<?> kind = event.kind();
        if (kind.equals(StandardWatchEventKinds.OVERFLOW)) {
            if (PROP_IGN_OVERFLOW)
                continue; // Sometimes it's better to ignore than interrupt fair playing
            throw new IOException("Overflow");
        }

        // Resolve paths and verify is not exclusion
        Path path = watchDir.resolve((Path) event.context());
        Deque<String> stringPath = toPath(dir.relativize(path));
        if (matcher != null && !matcher.shouldVerify(stringPath))
            continue; // Exclusion; should not be verified
        // Verify is REALLY modified (not just attributes)
        if (kind.equals(StandardWatchEventKinds.ENTRY_MODIFY)) {
            HashedEntry entry = hdir.resolve(stringPath);
            if (entry != null && (entry.getType() != HashedEntry.Type.FILE || ((HashedFile) entry).isSame(path, digest)))
                continue; // Modified attributes, not need to worry :D
        }

        // Forbidden modification!
        throw new SecurityException(String.format("Forbidden modification (%s, %d times): '%s'", kind, event.count(), path));
    }
    key.reset();
}
 

public AbstractWatchKey(
    AbstractWatchService watcher,
    Watchable watchable,
    Iterable<? extends WatchEvent.Kind<?>> subscribedTypes,
    int queueSize) {
  this.watcher = requireNonNull(watcher);
  this.watchable = watchable; // nullable for Watcher poison
  this.events = new ArrayBlockingQueue<>(queueSize);

  Set<Kind<?>> types = new HashSet<Kind<?>>();
  subscribedTypes.forEach(types::add);
  this.subscribedTypes = Collections.unmodifiableSet(types);
}
 

protected JWatchKey register(JPath path, Kind<?>[] events, Modifier ... modifiers)
{
  JWatchKey key = new JWatchKey(this, path, events, modifiers);

  synchronized (this) {
    _watchList.add(key);
  }

  return key;
}
 

public JWatchKey(JWatchService watchService,
                 JPath path,
                 Kind<?>[] events,
                 Modifier ... modifiers)
{
  Objects.requireNonNull(events);

  _watchService = watchService;
  _path = path;
  _events = events;
  _modifiers = modifiers;

  _watchHandle = path.getBfsFile().watch(pathString -> onWatch(pathString));
}
 

@Override
public WatchKey register(WatchService watcher, Kind<?>[] events,
                         Modifier... modifiers) throws IOException
{
  if (events.length == 0) {
    throw new IllegalArgumentException(L.l("no events specified to watch on: {0}", toUri()));
  }

  JWatchService jWatcher = (JWatchService) watcher;

  WatchKey key = jWatcher.register(this, events, modifiers);

  return key;
}
 

/**
 * Process watch events.
 *
 * @param key the key
 * @param keys the keys
 */
private void processWatchEvents(WatchKey key, List<WatchEvent<?>> keys) {
    for (WatchEvent<?> watchEvent : keys) {

        Kind<?> watchEventKind = watchEvent.kind();
        // Sometimes events are created faster than they are registered
        // or the implementation may specify a maximum number of events
        // and further events are discarded. In these cases an event of
        // kind overflow is returned. We ignore this case for now
        if (watchEventKind == StandardWatchEventKinds.OVERFLOW) {
            continue;
        }

        Path dir = (Path) key.watchable();
        Path fullPath = dir.resolve((Path) watchEvent.context());

        FileWatcherUpdateInterface parentObj = watcherMap.get(key);
        if (parentObj != null) {
            if (watchEventKind == StandardWatchEventKinds.ENTRY_CREATE) {
                // A new file has been created
                parentObj.fileAdded(fullPath);
            } else if (watchEventKind == StandardWatchEventKinds.ENTRY_MODIFY) {
                ReloadManager.getInstance().fileModified(fullPath);
                // The file has been modified.
                parentObj.fileModified(fullPath);
            } else if (watchEventKind == StandardWatchEventKinds.ENTRY_DELETE) {
                parentObj.fileDeleted(fullPath);
            }
        }
    }
}
 

@SuppressWarnings("unchecked")
private static void processEvents(File watchedDir, Path file) {
    for (;;) {

        WatchKey key;
        try {
            key = watcher.take();
        } catch (InterruptedException x) {
            return;
        }

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

            WatchEvent<Path> ev = (WatchEvent<Path>)event;
            Path name = ev.context();
            Path child = watchedDir.toPath().resolve(name);

            if (kind == ENTRY_DELETE && child.equals(file)) {
                return;
            }
        }

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

@Override
protected void processWatchEvent(WatchEvent<?> event, Kind<?> kind, Path path) {
    File file = path.toFile();
    if (!file.isHidden()) {
        if (ENTRY_DELETE.equals(kind)) {
            provider.removeResources(file);
        } else if (file.canRead()) {
            provider.importResources(file);
        }
    }
}
 

@Override
protected Kind<?>[] getWatchEventKinds(Path directory) {
    if (directory != null && isNotEmpty(folderFileExtMap)) {
        String folderName = directory.getFileName().toString();
        if (folderFileExtMap.containsKey(folderName)) {
            return new Kind<?>[] { ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY };
        }
    }
    return null;
}
 

@Override
protected void processWatchEvent(WatchEvent<?> event, Kind<?> kind, Path path) {
    File toCheck = getFileByFileExtMap(folderFileExtMap, path.getFileName().toString());
    if (toCheck != null && !toCheck.isHidden()) {
        checkFile(modelRepository, toCheck, kind);
    }
}
 

@Override
public WatchKey register(WatchService watcher, Kind<?>[] events,
    Modifier... modifiers) throws IOException {
  if (watcher == null || events == null || modifiers == null) {
    throw new NullPointerException();
  }

  // Not implemented now
  // The Hadoop API for notification is not stable
  throw new IOException("Not implemented");
}
 

@Override
public WatchKey register(
    WatchService watcher, WatchEvent.Kind<?>[] events, WatchEvent.Modifier... modifiers)
    throws IOException {
  // TODO(buck_team): do not recourse to default Path implementation
  return asDefault().register(watcher, events, modifiers);
}
 

@Override
protected void processWatchEvent(WatchEvent<?> event, Kind<?> kind, Path path) {
    File toCheck = getFileByFileExtMap(folderFileExtMap, path.getFileName().toString());
    if (toCheck != null && !toCheck.isHidden()) {
        checkFile(modelRepo, toCheck, kind);
    }
}
 

@Override
protected void processWatchEvent(WatchEvent<?> event, Kind<?> kind, Path path) {
    File file = path.toFile();
    if (!file.isHidden()) {
        if (kind.equals(ENTRY_DELETE)) {
            provider.removeResources(file);
        } else if (file.canRead()) {
            provider.importResources(file);
        }
    }
}
 

public UnixSshPathWatchKey( UnixSshFileSystemWatchService watchService, UnixSshPath dir, Kind<?>[] kinds, long pollingInterval, TimeUnit pollingIntervalTimeUnit ) {
    this.watchService = watchService;
    this.dir = dir;
    this.kindsToWatch = new HashSet<>();
    this.kindsToWatch.addAll( Arrays.asList( kinds ) );
    this.pollingInterval = pollingInterval;
    this.pollingIntervalTimeUnit = pollingIntervalTimeUnit;
    this.cancelled = false;
    this.initialized = false;
    this.addMap = new HashMap<>();
    this.deleteMap = new HashMap<>();
    this.modifyMap = new HashMap<>();
    this.state = State.READY;
}
 

public void watchVideoCaptureSystem(Path path) throws IOException, InterruptedException {

        try (WatchService watchService = FileSystems.getDefault().newWatchService()) {
            path.register(watchService, StandardWatchEventKinds.ENTRY_CREATE);

            System.out.println("Watching captures ...");
            
            //start an infinite loop           
            while (true) {

                //retrieve and remove the next watch key
                final WatchKey key = watchService.poll(11, TimeUnit.SECONDS);

                if (key == null) {
                    throw new IllegalStateException("The video capture system is jammed. Missed capture!");                    
                }

                //get list of events for the watch key
                for (WatchEvent<?> watchEvent : key.pollEvents()) {

                    //get the kind of event (create, modify, delete)
                    final Kind<?> kind = watchEvent.kind();

                    //handle OVERFLOW event
                    if (kind == StandardWatchEventKinds.OVERFLOW) {
                        continue;
                    }

                    if (kind == StandardWatchEventKinds.ENTRY_CREATE) {

                        //get the filename for the event
                        final WatchEvent<Path> watchEventPath = (WatchEvent<Path>) watchEvent;
                        final Path filename = watchEventPath.context();
                        final Path child = path.resolve(filename);

                        if (Files.probeContentType(child).equals("image/jpeg")) {

                            //print it out the video capture time
                            SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MMM-dd HH:mm:ss");
                            System.out.println("Video capture successfully at: " + dateFormat.format(new Date()));
                        } else {
                            Files.deleteIfExists(child);
                            throw new IllegalStateException("Unauthorized file type has been added!");  
                        }
                    }

                    //reset the key
                    boolean valid = key.reset();

                    //exit loop if the key is not valid (if the directory was deleted, per example)
                    if (!valid) {
                        break;
                    }
                }
            }
        }
    }
 

public void watchTray(Path path) throws IOException, InterruptedException {
    try (WatchService watchService = FileSystems.getDefault().newWatchService()) {
        path.register(watchService, StandardWatchEventKinds.ENTRY_CREATE,
                StandardWatchEventKinds.ENTRY_DELETE);

        System.out.println("Printer watcher ready ...");
        
        //start an infinite loop
        while (true) {

            //retrieve and remove the next watch key
            final WatchKey key = watchService.poll(10, TimeUnit.SECONDS);

            //get list of events for the watch key
            if (key != null) {
                for (WatchEvent<?> watchEvent : key.pollEvents()) {

                    //get the filename for the event
                    final WatchEvent<Path> watchEventPath = (WatchEvent<Path>) watchEvent;
                    final Path filename = watchEventPath.context();

                    //get the kind of event (create, modify, delete)
                    final Kind<?> kind = watchEvent.kind();

                    //handle OVERFLOW event
                    if (kind == StandardWatchEventKinds.OVERFLOW) {
                        continue;
                    }

                    if (kind == StandardWatchEventKinds.ENTRY_CREATE) {
                        System.out.println("Sending the document to print -> " + filename);

                        Runnable task = new Printer(path.resolve(filename));
                        Thread worker = new Thread(task);

                        //we can set the name of the thread			
                        worker.setName(path.resolve(filename).toString());

                        //store the thread and the path
                        threads.put(worker, path.resolve(filename));

                        //start the thread
                        worker.start();
                    }

                    if (kind == StandardWatchEventKinds.ENTRY_DELETE) {
                        System.out.println(filename + " was successfully printed!");
                    }
                }

                //reset the key
                boolean valid = key.reset();

                //exit loop if the key is not valid (if the directory was deleted, per example)
                if (!valid) {
                    threads.clear();
                    break;
                }
            }

            if (!threads.isEmpty()) {
                for (Iterator<Map.Entry<Thread, Path>> it = 
                        threads.entrySet().iterator(); it.hasNext();) {
                    Map.Entry<Thread, Path> entry = it.next();
                    if (entry.getKey().getState() == Thread.State.TERMINATED) {
                        Files.deleteIfExists(entry.getValue());
                        it.remove();
                    }
                }
            }
        }
    }
}
 

public void watchFolder(Path path) throws IOException, InterruptedException {
    try (WatchService watchService = FileSystems.getDefault().newWatchService()) {
        path.register(watchService, StandardWatchEventKinds.ENTRY_CREATE,
                StandardWatchEventKinds.ENTRY_MODIFY, StandardWatchEventKinds.ENTRY_DELETE);

        System.out.println("Watching: " + path);

        //start an infinite loop
        while (true) {

            //retrieve and remove the next watch key
            final WatchKey key = watchService.take();

            //get list of pending events for the watch key
            for (WatchEvent<?> watchEvent : key.pollEvents()) {

                //get the kind of event (create, modify, delete)
                final Kind<?> kind = watchEvent.kind();

                //handle OVERFLOW event
                if (kind == StandardWatchEventKinds.OVERFLOW) {
                    continue;
                }

                //get the filename for the event
                final WatchEvent<Path> watchEventPath = (WatchEvent<Path>) watchEvent;
                final Path filename = watchEventPath.context();

                //print it out
                System.out.println(kind + " -> " + filename);
            }

            //reset the key
            boolean valid = key.reset();

            //exit loop if the key is not valid (if the directory was deleted, per example)
            if (!valid) {
                break;
            }

        }
    }
}