package com.baeldung.servlets; import javax.servlet.RequestDispatcher; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.Cookie; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.util.Optional; /** * Created by adam. */ @WebServlet(name = "WelcomeServlet", urlPatterns = "/welcome") public class WelcomeServlet extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { CookieReader cookieReader = new CookieReader(request); Optional uiColor = cookieReader.readCookie("uiColor"); Optional userName = cookieReader.readCookie("userName"); if (!userName.isPresent()) { response.sendRedirect("/login"); } else { request.setAttribute("uiColor", uiColor.orElse("blue")); request.setAttribute("userName", userName.get()); request.setAttribute("sessionAttribute", request.getSession() .getAttribute("sampleKey")); RequestDispatcher dispatcher = request.getRequestDispatcher("/WEB-INF/jsp/welcome.jsp"); dispatcher.forward(request, response); } } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException { Cookie userNameCookieRemove = new Cookie("userName", ""); userNameCookieRemove.setMaxAge(0); response.addCookie(userNameCookieRemove); response.sendRedirect("/login"); } }