An AU extension (AuExtension) is a small program that can be plugged into ZK Update Engine (DHtmlUpdateServlet) and extend its functionality. Actually our file upload and multimedia viewing are implemented as an AU extension that you can replace with your implementation.
An AU extension is associated with a name starting with slash, such as "/upload". Then each time a request targeting /zkau/upload will be forwarded to this extension for service.
To register an AU extension, you could specify the name and the class name as the initial parameter of the declaration of ZK Update Engine in
WEB-INF/web.xml. For more information, please refer to ZK Configuration Reference.
If you want to register it in Java, you could use DHtmlUpdateServlet.addAuExtension(String, AuExtension) instead.