效果
Servlet
import jakarta.servlet.*; import jakarta.servlet.http.*; import jakarta.servlet.annotation.*; import java.io.IOException; import java.util.Date; @WebServlet(name = "Login", value = "/login") public class ServletLogin extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); HttpSession st =request.getSession(); if(st.getAttribute("LoginTime")==null){ response.getWriter().println("首次登陆"); }else{ response.getWriter().println("上次登陆时间 | "+request.getSession().getAttribute("LoginTime")); } st.setAttribute("LoginTime", new Date()); st.setMaxInactiveInterval(60*60); response.getWriter().println("<br/>现在登陆时间 | "+request.getSession().getAttribute("LoginTime")); } }
import jakarta.servlet.*; import jakarta.servlet.http.*; import jakarta.servlet.annotation.*; import java.io.IOException; import java.util.Date; @WebServlet(name = "Login", value = "/login") public class ServletLogin extends HttpServlet { @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); HttpSession st =request.getSession();//获取Session if(st.getAttribute("LoginTime")==null){//判断是否有需要的内容 //如果为null，说明是首次访问 response.getWriter().println("首次登陆"); }else{ //如果不为null，说明访问过了 response.getWriter().println("上次登陆时间 | "+request.getSession().getAttribute("LoginTime"));//通过request获取上次访问时间 } st.setAttribute("LoginTime", new Date());//记录这次新的访问时间 st.setMaxInactiveInterval(60*60);//设置Session有效时间 单位为秒 response.getWriter().println("<br/>现在登陆时间 | "+request.getSession().getAttribute("LoginTime")); } }
JSP
<%-- Created by IntelliJ IDEA. User: xrilang Date: 28/12/2021 Time: 10:43 --%> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>$Title$</title> </head> <body> <a href="${pageContext.request.contextPath}/login">go</a> </body> </html>
参考
