export media library (umbraco v6 + umbraco v7)

MediaExportController.cs

using System;
using System.IO;
using System.Web.Hosting;
using Umbraco.Core;
using Umbraco.Core.Logging;
using Umbraco.Core.Models;
using Umbraco.Web;
using Umbraco.Web.WebApi;

/// <summary>
/// Summary description for MediaExportController
/// </summary>
public class MediaExportController : UmbracoAuthorizedApiController
{
    private string targetFolder = "~/App_Data/mediaExport";

    public string GetPath()
    {
        var fullExportPath = HostingEnvironment.MapPath(targetFolder);
        if (fullExportPath == null)
        {
            throw new DirectoryNotFoundException(targetFolder);
        }

        if (Directory.Exists(fullExportPath))
        {
            // delete the current export
            Directory.Delete(fullExportPath, true);
        }

        var exportDirectory = new DirectoryInfo(fullExportPath);

        var rootMedias = Umbraco.TypedMediaAtRoot();
        foreach (var rootMedia in rootMedias)
        {
            TraverseFolder(rootMedia, exportDirectory);
        }

        return targetFolder;
    }

    private void TraverseFolder(IPublishedContent rootMedia, DirectoryInfo directory)
    {
        // If current item is not a folder
        if (rootMedia.ItemType == PublishedItemType.Media && rootMedia.DocumentTypeAlias != "Folder")
        {
            // store rootMedia.Path
            var srcPath =
                HostingEnvironment.MapPath(rootMedia.GetPropertyValue<string>(Constants.Conventions.Media.File));
            var fileInfo = new FileInfo(srcPath);
            try
            {
                System.IO.File.Copy(srcPath, directory.FullName + "\\" + fileInfo.Name);
            }
            catch (Exception ex)
            {
                //if (Debugger.IsAttached) Debugger.Break();
                LogHelper.Error<MediaExportController>("could not copy", ex);
            }
            return;
        }

        // If current item is a folder, 
        // Create subfolder
        var folderName = rootMedia.UrlName;
        var newFolder = directory.CreateSubdirectory(folderName);

        // and loop children
        foreach (var mediaItem in rootMedia.Children)
        {
            TraverseFolder(mediaItem, newFolder);
        }
    }
}