如何从Servlet发出警报响应？

Question

I would like to do an alert confirmation when user submits a form, how do I do that?

I've used:

PrintWriter out = response.getWriter();  
response.setContentType("text/html");  
out.println("<script type=\"text/javascript\">");  
out.println("alert('form submitted!');");  
out.println("</script>");

but it leaves the page blank.

how do I do the alert without refreshing the background page?

Answer 1

You need to use AJAX. All normal requests result in a new page being served.

btw: alert() is a bit of a blunt tool and is not considered be part of a "good user experience". You may want to have a modal dialog instead.