The interface org.apache.struts.upload.FormFile is used for the struts file upload application. This interface represents a file that has been uploaded by a client. It is the only interface or class in upload package which is typically referenced directly by a Struts application.
This is not specific to Struts in case of DHTML but the two things that are needed in DHTML page is: first, the form needs to specify an enctype of multipart/form-data and second an <input> form control of type file.
When the page is loaded in the browser, following action takes place:
AngularJS scans through the HTML to look for AngularJS applications and views. Once view is located, it then connects that view to the corresponding controller function.
Then, AngularJS executes the controller functions. It then renders the views with data from the model populated by the controller. The page is ready.