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。
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)
<body> <% String user = (String) session.getAttribute("user"); if (user == null) { response.sendRedirect("login.jsp"); } %> 欢迎你<%=user%> <a href="MyJsp1.jsp">退出登录</a> <form action="MyJsp2.jsp" method="post"> <table border="1" cellpadding="0" cellspacing="0" width="500"> <thead> <tr> <th>商品名称</th> <th>价格</th> <th>加购</th> </tr> </thead> <tbody> <tr> <td>西瓜</td> <td>28.76</td> <td align="center"><input type="checkbox" name="sp" value="西瓜"> </td> </tr> <tr> <td>芒果</td> <td>11.98</td> <td align="center"><input type="checkbox" name="sp" value="芒果"> </td> </tr> <tr> <td>香蕉</td> <td>12.14</td> <td align="center"><input type="checkbox" name="sp" value="香蕉"> </td> </tr> <tr> <td>火龙果</td> <td>8.76</td> <td align="center"><input type="checkbox" name="sp" value="火龙果"> </td> </tr> <tr> <td colspan="4"><input type="submit" value="加购"> </td> </tr> </tbody> </table> </form> </body>
<body> <script> function yz() { if (form.user.value == "") { alert('用户名不能为空'); return; } if (form.password.value == "") { alert('密码不能为空'); return; } form.submit(); } </script> <form action="index.jsp" method="post" name="form"> <table> <tr> <td>用户名:</td> <td><input type="text" name="user"></td> <td>密码:</td> <td><input type="password" name="password"></td> <td><input type="button" value="登录" onclick="yz()"></td> </tr> </table> </form> </body>
<body> <% String user = request.getParameter("user"); String password = request.getParameter("password"); if (user.equals(password)) { session.setAttribute("user", user); request.getRequestDispatcher("main.jsp").forward(request, response); } else { response.sendRedirect("login.jsp"); } %> </body>
<body> <% session.invalidate(); response.sendRedirect("login.jsp"); %> </body>
<body> <% request.setCharacterEncoding("utf-8"); String[] sp = request.getParameterValues("sp"); for (int i = 0; sp != null && i < sp.length; i++) { out.print(sp[i] + "<br>"); } %> </body>