chat application using jsp and servlets

Question

I am developing chat appliction using jsp and servlets. Can anyone tell me, what are the possiblities to notify the administrator (trigger events in administrator account), when the client hits the "Startchat " button?

Answer 1

DWR might offer a solution for use in webapp. for other solutions, you can search google for 'java' and 'comet'

Answer 2

Since it is a chat application can't you have the user send a message to the administrator when a client hits the Start chat button?

Answer 3

Just let the button fire a HTTP request to the server side which in turn invokes the Servlet associated with the url-pattern of the particular HTTP request. The request can be fired either synchronously with a simple link or form:

<form action="servletUrl">
    <input type="submit" value="Startchat">
</form>

...or asynchronously with help of a shot of JavaScript/Ajax. jQuery is of great help here:

$('#buttonId').click(function() {
    $.get('servletUrl', function() {
        // Callback here.
    });
});

...

<button id="buttonId">Startchat</button>

Finally in the Servlet associated with the url-pattern of /servletUrl just do the desired task to notify the administrator. As you didn't tell in what way you'd like to notify the administrator (there are dozens, as Bozho stated in a comment), I'll only give a trivial kickoff example:

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    notifyAdministratorAbout(request);

    if (not requested by ajax) {
        request.setAttribute("start", true);
        request.getRequestDispatcher("chat.jsp").forward(request, response);
    }
}