Figure 2. Notify a WinForms App of a Database Update. You can extend DAO to include update operations, using .NET Remoting between the Java client and the WinForms app. The Java DAO adds a new record to the database, then uses a .NET Remoting call to tell the WinForms app it should refresh its view of the database. The WinForms app's exposed server-side component is attached to an event in code. When an incoming call is made by the Java DAO, the event triggers a screen refresh.