public void run()

in flink-kubernetes-operator/src/main/java/org/apache/flink/kubernetes/operator/fs/FileSystemWatchService.java [50:85]
35 lines of code
9 McCabe index (conditional complexity)

    public void run() {
        try (WatchService watcher = FileSystems.getDefault().newWatchService()) {
            LOG.info("Starting watching path: " + directoryPath);
            Path realDirectoryPath = Paths.get(directoryPath).toRealPath();
            LOG.info("Path is resolved to real path: " + realDirectoryPath);
            realDirectoryPath.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);
            onWatchStarted(realDirectoryPath);

            while (true) {
                LOG.debug("Taking watch key");
                WatchKey watchKey = watcher.take();
                LOG.debug("Watch key arrived");
                for (WatchEvent<?> watchEvent : watchKey.pollEvents()) {
                    LOG.debug("Watch event count: " + watchEvent.count());
                    if (watchEvent.kind() == OVERFLOW) {
                        LOG.error("Filesystem events may have been lost or discarded");
                        Thread.yield();
                    } else if (watchEvent.kind() == ENTRY_CREATE) {
                        onFileOrDirectoryCreated((Path) watchEvent.context());
                    } else if (watchEvent.kind() == ENTRY_DELETE) {
                        onFileOrDirectoryDeleted((Path) watchEvent.context());
                    } else if (watchEvent.kind() == ENTRY_MODIFY) {
                        onFileOrDirectoryModified((Path) watchEvent.context());
                    } else {
                        throw new IllegalStateException("Invalid event kind: " + watchEvent.kind());
                    }
                }
                watchKey.reset();
            }
        } catch (InterruptedException e) {
            LOG.info("Filesystem watcher interrupted");
        } catch (Exception e) {
            LOG.error("Filesystem watcher received exception and stopped: " + e);
            throw new RuntimeException(e);
        }
    }