<input type="submit" value="Send" id="click" name="click"/>
if(request.getParameter("click")!=null)
{
request.sendRedirect("URL");
}
или
public class Dispatcher extends HttpServlet
{
public void doGet(HttpServletRequest request, HttpServletResponse response)
{
RequestDispatcher dispatcher =
request.getRequestDispatcher("URL");
if (dispatcher != null) dispatcher.forward(request, response);
}
}
Google ищет разницу между request.sendRedirect("URL");
и request.getRequestDispatcher("URL");