Package com.ithit.webdav.server.synchronization

Interface SynchronizationCollection

All Superinterfaces:
Folder, HierarchyItem
public interface SynchronizationCollection extends Folder
This specification defines an extension to Web Distributed Authoring and Versioning (WebDAV) that allows efficient synchronization of he contents of a WebDAV collection.

  • Method Details

    • getChanges

      Changes getChanges(List<Property> propNames, String syncToken, boolean deep, Long limit) throws ServerException
      Returns a list of changes that correspond to a synchronization request.
      Parameters:
      propNames - List of properties to retrieve with the children. They will be queried by the engine later.
      syncToken - The synchronization token provided by the server and returned by the client.
      deep - Indicates the "scope" of the synchronization report request, false - immediate children and true - all children at any depth.
      limit - Limits the number of member URLs in a response.
      Returns:
      Changes details for the folder.

      The code below is part of Collection Synchronization sample provided with the SDK. 
          @Override
    public Changes getChanges(List<Property> propNames, String syncToken, boolean deep, Long limit) throws ServerException {
        DavChanges changes = new DavChanges();
        Long syncUsn = null;
        Long maxUsn = 0L;

        if (!StringUtil.isNullOrEmpty(syncToken)) {
            syncUsn = Long.parseLong(syncToken);
        }
        List<Pair<HierarchyItemImpl, Long>> children = new ArrayList<>();
        try (Stream<Path> stream = Files.walk(Paths.get(getFullPath().toString()), deep ? Integer.MAX_VALUE : 1)) {
            for (String path : stream.map(Path::toString).collect(Collectors.toSet())) {
                String childPath = StringUtil.trimEnd(getPath(), "/") + "/" + StringUtil.trimStart(path.substring(getFullPath().toString().length()).replace(java.io.File.separator, "/"), "/");
                HierarchyItemImpl child = FolderImpl.getFolder(childPath, getEngine());

                if (child == null) {
                    child = FileImpl.getFile(childPath, getEngine());
                }

                if (child != null) {
                    children.add(new ImmutablePair<>(child, FileSystemExtension.getUsn(path)));
                }
            }
        } catch (IOException ex) {
            throw new ServerException(ex);
        }

        if (limit != null && limit == 0) {
            maxUsn = children.stream().mapToLong(Pair::getValue).max().orElse(0);
        } else {
            for (Pair<HierarchyItemImpl, Long> item : children.stream().sorted(Comparator.comparingLong(Pair::getValue)).collect(Collectors.toCollection(LinkedHashSet::new))) {
                // Don't include deleted files/folders when syncToken is empty, because this is full sync.
                if (!(item.getLeft().getChangeType() == Change.DELETED && StringUtil.isNullOrEmpty(syncToken))) {
                    maxUsn = item.getValue();
                    if (syncUsn == null || item.getValue() > syncUsn) {
                        changes.add(item.getLeft());
                    }

                    if (limit != null && limit <= changes.size()) {
                        changes.setMoreResults(true);
                        break;
                    }
                }
            }
        }
        changes.setNewSyncToken(maxUsn.toString());

        return changes;
    }
      Throws:
      ServerException