response.setStatus(HttpServletResponse.SC_FORBIDDEN);
response.sendRedirect("login.jsp");
HTTPServletResponse.SC_BAD_REQUEST: 400
HTTPServletResponse.SC_FOUND: 302
HTTPServletResponse.SC_METHOD_NOT_ALLOWED: 405
HTTPServletResponse.SC_NON_AUTHORITATIVE_INFORMATION: 203
HTTPServletResponse.SC_FORBIDDEN: 403
HTTPServletResponse.SC_NOT_FOUND: 404
HTTPServletResponse.SC_OK: 200