第八周
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。
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head> <title></title> <script type="text/javascript"> function fv() { if (Form.name.value=="") { alert("账号不能为空"); return; } if (Form.password.value=="") { alert("密码不能为空"); return; } Form.submit(); } </script> </head> <body> <form name="Form" action="index1.jsp" method="post"> 账号：<input type="text" name="name" value="111"><br> 密码：<input type="password" name="password" value="111"> <br> <input type="submit" value="登录" onclick="fv()"> </form> </body> </html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head> <title></title> </head> <body> <% request.setCharacterEncoding("utf-8"); String name = request.getParameter("name"); String password = request.getParameter("password"); if (name.equals(password)) { session.setAttribute("name", name); request.getRequestDispatcher("index2.jsp").forward(request, response); } else { response.sendRedirect("index3.jsp"); } %> </body> </html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head> <title></title> </head> <body> <% String name=(String)session.getAttribute("name"); //如果他是空，说明没登陆，直接访问该页面了 if(name==null) response.sendRedirect("index.jsp"); %> <a href="index.jsp">退出登录</a> <br>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head> <title></title> </head> <body> 登陆失败，请重新登录 <% response.setHeader("refresh", "5;url=index.jsp"); %> </body> </html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head> <title></title> </head> <body> <% session.invalidate(); response.setHeader("refresh", "5;url=index.jsp"); %> 退出成功! </body> </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）
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head> <title></title> <script type="text/javascript"> function fv() { if (Form.name.value=="") { alert("账号不能为空"); return; } if (Form.password.value=="") { alert("密码不能为空"); return; } Form.submit(); } </script> </head> <body> <form name="Form" action="index1.jsp" method="post"> 账号：<input type="text" name="name" value="111"><br> 密码：<input type="password" name="password" value="111"> <br> <input type="submit" value="登录" onclick="fv()"> </form> </body> </html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head> <title></title> </head> <body> <% request.setCharacterEncoding("utf-8"); String name = request.getParameter("name"); String password = request.getParameter("password"); if (name.equals(password)) { session.setAttribute("name", name); request.getRequestDispatcher("index2.jsp").forward(request, response); } else { response.sendRedirect("index3.jsp"); } %> </body> </html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head> <title></title> </head> <body> <% String name=(String)session.getAttribute("name"); if(name==null) response.sendRedirect("index.jsp"); %> <a href="index.jsp">退出登录</a> <br> <form action="index5.jsp"> <input name="book" type="checkbox" value="java web"> java web ￥100<br> <input name="book" type="checkbox" value="java"> java ￥200<br> <input name="book" type="checkbox" value="android"> android ￥300<br> <hr> <input type="submit" value="加入购物车"> </form> </body> </html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head> <title></title> </head> <body> 登陆失败，请重新登录 <% response.setHeader("refresh", "5;url=index.jsp"); %> </body> </html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head> <title></title> </head> <body> <% session.invalidate(); response.setHeader("refresh", "5;url=index.jsp"); %> 退出成功! </body> </html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <head> <title></title> </head> <body> <% request.setCharacterEncoding("utf-8"); String book[]=request.getParameterValues("book"); if(book==null){ out.print("购物车为空"); } else{ for(int i=0;i<book.length;i++){ out.print("("+(i+1)+")"+book[i]+"<br>"); } } %> </body> </html>
