Categorize the Exchange folders into Distinguished Folder and Normal Folder

My question is how to make difference between a distinguished folders and a folder created by user when I try to obtain the list of user folders using findFolder web service method:

    FindFolderType request = new FindFolderType();

    request.setTraversal(FolderQueryTraversalType.DEEP);

    FolderResponseShapeType folderResponseShapeType = new FolderResponseShapeType();
    folderResponseShapeType.setBaseShape(DefaultShapeNamesType.ALL_PROPERTIES);
    request.setFolderShape(folderResponseShapeType);

    NonEmptyArrayOfBaseFolderIdsType folderIds = new NonEmptyArrayOfBaseFolderIdsType();
    DistinguishedFolderIdType folderId = new DistinguishedFolderIdType();
    folderId.setId(DistinguishedFolderIdNameType.MSGFOLDERROOT);
    folderIds.getFolderIdOrDistinguishedFolderId().add(folderId);
    request.setParentFolderIds(folderIds);

    //respo开发者_JS百科nse
    Holder<FindFolderResponseType> findFolderResult = new Holder<FindFolderResponseType>();

    addHandlers(port);

    port.findFolder(
            request,
            getImpersonation(smtpAddress),
            getSerializedSecurityContextType(),
            MAILBOX_CULTURE,
            getServerVersion(),
            findFolderResult,
            serverVersion);

I can not see any property to distinct between these 2 types of folders.

Thank you

From http://social.technet.microsoft.com/Forums/exchange/en-US/57551bd1-d1e1-4913-bbb2-e2abbca02a3f/how-do-i-distinguish-the-user-create-folders-from-all-the-msgfolders?forum=exchangesvrdevelopment:

"Call GetFolder (IdOnly) and pass in all the enumeration values from DistinguishedFolderIdNamesType and stick the resulting FolderIds in a dictionary (FolderId.Id to Enum). Then when you want to see if a given Folder is "distinguished" or not, just check to see if the key exists in your dictionary."