import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class Demo2 extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
    //服务端通知浏览器3秒后转到目标页面
                response.setHeader("refresh","3;url=/day04/my.html");
                }
            }

http://localhost:8080/day04/Dome2