jsp隐藏表单域实现会话跟踪

来源：互联网发布：学历网络教育费用编辑：程序博客网时间：2024/05/18 00:58

1.新建一个Dynamic Web Project项目，里面新建两个java文件和一个jsp文件，整体的框架如下所示：

2.login.jsp里面的代码如下所示：

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title></title></head><body><form action="login" method="post"><table><tr><td>用户名：</td><td><input type="text" name="user" /></td></tr><tr><td><input type="submit" value="提交" /></td></tr></table></form></body></html>

3.GreetServlet.java文件里面的代码如下所示:

package servlet;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletConfig;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@WebServlet(name = "greet", urlPatterns = { "/greet" })public class GreetServlet extends HttpServlet {private static final long serialVersionUID = 1L;@Overridepublic void init(ServletConfig config) throws ServletException {super.init(config);}protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}protected void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {response.setContentType("text/html;charset=utf-8");PrintWriter out = response.getWriter();request.setCharacterEncoding("utf-8");String name = request.getParameter("user");if (name == null || name.trim().length() == 0) {response.sendRedirect("login.jsp");} else {out.println("<html><body>");out.println("<br>您的姓名是：" + name);out.println("<br><a href=login.jsp" + ">重新登录</a>");out.println("</html></body>");}}}

4.LoginServlet.java文件里面的代码如下所示：

package servlet;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletConfig;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@WebServlet(name = "login", urlPatterns = { "/login" })public class LoginServlet extends HttpServlet {private static final long serialVersionUID = 1L;@Overridepublic void init(ServletConfig config) throws ServletException {super.init(config);}@Overrideprotected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {doPost(request, response);}@Overrideprotected void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {response.setContentType("text/html;charset=utf-8");PrintWriter out = response.getWriter();request.setCharacterEncoding("utf-8");String name = request.getParameter("user");if (name == null || name.trim().length() == 0) {response.sendRedirect("login.jsp");} else {out.println("<html><head><title>第二个页面</title></head><body>");out.println("<form action='greet'" + " method='post'");out.println("<input type='hidden' name='user' value=" + name + ">");out.println(name + "<br>");out.println("<input type='submit' value='转向下一个页面看看'>");out.println("</form>");out.println("</body></html>");}}}

5.在浏览器里面输入http://localhost:8080/Servlet/login.jsp运行得到的结果如下所示：

阅读全文

0 0