JSP第六次作业
1.登陆
输入用户名密码，判断用户名和密码相同，登陆成功，session中保存用户的用户名，进入主页main.jsp，主页有一个退出按钮，点击，回到登陆页login.jsp。要求：退出登录后，如果在浏览器直接输入主页main.jsp，访问不了，直接跳到登陆页。
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 3 <html> 4 <head> 5 <title>My JSP 'login.jsp' starting page</title> 6 </head> 7 <body> 8 <form action="dologin.jsp" method="post" name="login"> 9 用户名：<input type="text" name="uname" size="20"><br> 10 密 码：<input type="password" name="upwd" size="20"><br> 11 <input type="button" value="登录" onClick="validate()"> 12 </form> 13 <script type="text/javascript"> 14 function validate() { 15 if (login.uname.value == "") { 16 alert("用户名不能为空!"); 17 return; 18 } 19 if (login.upwd.value == "") { 20 alert("密码不能为空!"); 21 return; 22 } 23 login.submit(); 24 } 25 </script> 26 </body> 27 </html>
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 3 <html> 4 <head> 5 <title>My JSP 'dologin.jsp' starting page</title> 6 </head> 7 <body> 8 <% 9 //设置编码 10 request.setCharacterEncoding("UTF-8"); 11 response.setCharacterEncoding("UTF-8"); 12 //获取请求数据 13 String uname = request.getParameter("uname"); 14 String upwd = request.getParameter("upwd"); 15 //判断密码和用户名是否相同 16 if (uname.equals(upwd)) { 17 session.setAttribute("uname",uname); 18 request.getRequestDispatcher("main.jsp") 19 .forward(request, response); 20 } else { 21 response.sendRedirect("no.jsp"); 22 } 23 %> 24 </body> 25 </html>
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 3 <html> 4 <head> 5 <title>My JSP 'main.jsp' starting page</title> 6 </head> 7 8 <body> 9 <% 10 String uname = (String) session.getAttribute("uname"); 11 //如果他是空，说明没登陆，直接访问该页面了 12 if (uname == null) { 13 response.sendRedirect("login.jsp"); 14 } 15 %> 16 欢迎你<%=uname%><br> 17 <a href="loginout.jsp">退出登录</a> 18 <br> 19 20 </body> 21 </html>
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 3 <html> 4 <head> 5 <title>My JSP 'loginout.jsp' starting page</title> 6 </head> 7 8 <body> 9 <% 10 session.invalidate();//结束会话 11 response.setHeader("refresh", "5;url=login.jsp"); 12 %> 13 </body> 14 </html>
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 3 <html> 4 <head> 5 <title>My JSP 'no.jsp' starting page</title> 6 </head> 7 8 <body> 9 <h1>登陆失败！！</h1> 10 <%response.setHeader("refresh", "5;url=login.jsp");%> 11 </body> 12 </html>
2.购物车
和上一题一起，在main.jsp中做一个购物车，里面显示3个商品名和价格 每一个后面有一个加入购物车按钮，main.jsp中有一个按钮（或者超链接）可以显示购物车。（选作：在购物车中加删除按钮删除商品）
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 3 <html> 4 <head> 5 <title>My JSP 'main.jsp' starting page</title> 6 </head> 7 8 <body> 9 <% 10 String uname = (String) session.getAttribute("uname"); 11 //如果他是空，说明没登陆，直接访问该页面了 12 if (uname == null) { 13 response.sendRedirect("login.jsp"); 14 } 15 %> 16 欢迎你<%=uname%><br> 17 <a href="loginout.jsp">退出登录</a> 18 <br> 19 <form action="buy.jsp"> 20 <hr> 21 是否加入购物车？<br> <input name="item" type="checkbox" value="weilong"> 22 辣条 $1<br> <input name="item" type="checkbox" value="xizhilang"> 23 果冻 $2<br> <input name="item" type="checkbox" value="menglong"> 24 雪糕 $3<br> 25 <hr> 26 <input type="submit" value="加入购物车"> 27 </form> 28 29 30 </body> 31 </html>
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 3 <html> 4 <head> 5 <title>My JSP 'buy.jsp' starting page</title> 6 </head> 7 8 <body> 9 10 <h2>购物车</h2> 11 <% 12 request.setCharacterEncoding("utf-8"); 13 String itemName[] = request.getParameterValues("item"); 14 if (itemName == null) { 15 out.print("购物车为空"); 16 } else { 17 for (int k = 0; k < itemName.length; k++) { 18 out.print("(" + (k + 1) + ")" + itemName[k] + "<br>"); 19 } 20 } 21 %> 22 23 </body> 24 </html>
