From Uploading Folders & Images in the bSpace Confluence by Ray Davis, last edited by Ray Davis on Aug 01, 2006
1. Re-use options
1.1. Commercial applets
There are plenty of commercial options. Most have free trials, but that doesn't do us much good as an open source project. So far I haven't spotted anything similar in the open source world. The big CMS products like Alfresco and Magnolia just do "Browse"-based single file uploads.
2. Development options - Browser
2.1. Web browser HTML / DHTML
2.2. Browser-embedded Flash
Flash in the browser doesn't support drops from the file system. The user has to upload via a "browse" dialog box, pretty much the same way as with plain HTML. (Even that level of functionality was only added in Flash 8.)
2.3. Browser-embedded Java applet
Most of the applets I've found have not provided access to their source code.
The exception is Gallery, which includes a simple "Upload Applet" (part of the Gallery Remote project) which accepts files and folders dragged-and-dropped from the file system, and allows multiple selections in its file browsing popup.
Who does it: Box.net, with a simple "Drop files here" popup. Aside from a progress bar, there's no other applet UI; when the files have been ingested, the applet goes dead and the browser content display is updated.
3. Development options - Multi-OS executable
3.1. Java application
Like the applet uploaders, most Java application uploaders do not provide source code. (At least one leverages Eclipse JARs, however.)
The exceptional open source Java uploader which handles drag-and-drop from the file system: Gallery Remote. Its source code is available in Subversion at "https://svn.sourceforge.net/svnroot/gallery/trunk/gallery_remote". Unfortunately the license is GPL, which is out of bounds for Sakai.
3.2. Yahoo Widgets
The Widget SDK includes support for dragging-and-dropping from the file system, which is how some third-parties have constructed Flickr client widgets.
4. Development options - OS-specific executable
Finally a chance to put our staff of crack Visual Basic, Gnome, and Xcode developers to work....
Who does it: Flickr.