JAVA servlets - open message popup

Question

I want to user HttpServletResponse object to compose a response that will tell the browser client to open a popup with some message - how can i do that?

Answer 1

Generally speaking, you can't.

Thanks to their popularity for annoying adverts, most browsers reject attempts to open popups that aren't a response to something the user does within a page.

If you just want to display messaging, you could just include it in a page, or output a script element with an alert statement in it.