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< > BotCompany Repo | #1019340 // Recursive Watcher Service Spike [dev.]

JavaX source code (desktop) - run with: x30.jar

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sclass RecursiWatcherService extends AutoCloseable {
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  File rootFolder;
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  WatchService watcher;
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  ExecutorService executor;
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  public void init() throws IOException {
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    watcher = FileSystems.getDefault().newWatchService();
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    executor = Executors.newSingleThreadExecutor();
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    startRecursiveWatcher();
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  }
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  void cleanMeUp() { close(); }
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  public void close() {
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    pcall { watcher.close(); }
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    executor.shutdown();
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  }
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    private void startRecursiveWatcher() throws IOException {
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        LOG.info("Starting Recursive Watcher");
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        final Map<WatchKey, Path> keys = new HashMap<>();
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        Consumer<Path> register = p -> {
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            if (!p.toFile().exists() || !p.toFile().isDirectory()) {
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                throw new RuntimeException("folder " + p + " does not exist or is not a directory");
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            }
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            try {
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                Files.walkFileTree(p, new SimpleFileVisitor<Path>() {
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                    @Override
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                    public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
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                        LOG.info("registering " + dir + " in watcher service");
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                        WatchKey watchKey = dir.register(watcher, new WatchEvent.Kind[]{ENTRY_CREATE}, SensitivityWatchEventModifier.HIGH);
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                        keys.put(watchKey, dir);
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                        return FileVisitResult.CONTINUE;
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                    }
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                });
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            } catch (IOException e) {
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                throw new RuntimeException("Error registering path " + p);
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            }
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        };
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        register.accept(rootFolder.toPath());
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        executor.submit(() -> {
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            while (true) {
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                final WatchKey key;
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                try {
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                    key = watcher.take(); // wait for a key to be available
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                } catch (InterruptedException ex) {
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                    return;
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                }
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                final Path dir = keys.get(key);
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                if (dir == null) {
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                    System.err.println("WatchKey " + key + " not recognized!");
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                    continue;
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                }
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                key.pollEvents().stream()
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                        .filter(e -> (e.kind() != OVERFLOW))
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                        .map(e -> ((WatchEvent<Path>) e).context())
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                        .forEach(p -> {
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                            final Path absPath = dir.resolve(p);
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                            if (absPath.toFile().isDirectory()) {
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                                register.accept(absPath);
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                            } else {
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                                final File f = absPath.toFile();
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                                LOG.info("Detected new file " + f.getAbsolutePath());
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                            }
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                        });
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                boolean valid = key.reset(); // IMPORTANT: The key must be reset after processed
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                if (!valid) {
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                    break;
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                }
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            }
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        });
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    }
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}

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Snippet ID: #1019340
Snippet name: Recursive Watcher Service Spike [dev.]
Eternal ID of this version: #1019340/1
Text MD5: 79658dc5046db62d09809c6bd6e1a2e8
Author: stefan
Category: javax / gui / a.i.
Type: JavaX source code (desktop)
Public (visible to everyone): Yes
Archived (hidden from active list): No
Created/modified: 2018-11-03 12:27:56
Source code size: 3048 bytes / 79 lines
Pitched / IR pitched: No / No
Views / Downloads: 361 / 564
Referenced in: [show references]