用户在login.jsp页面输入用户名密码登录：
如果用户名为xingoo，密码为123，则跳转到成功界面login_success.jsp，并显示用户登录的名字；
如果用户名密码错误，则跳转到失败界面login_failure.jsp，并提示返回登录界面。
login.jsp代码
<%@ 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>用户登录</title> </head> <body><h1>用户登录</h1><hr><form name="regForm" action="doLogin.jsp" method="post"><table><tr><td>username</td><td><input type="text" name="username"/></td></tr><tr><td>password</td><td><input type="password" name="password"/></td></tr><tr><td colspan="2"><input type="submit" value="submit"/></td></tr></table></form> </body> </html>
dologin.jsp处理代码
<%@ page language="java" contentType="text/html; charset=utf-8"pageEncoding="utf-8"%> <%String username = "";String password = "";request.setCharacterEncoding("utf-8");username = request.getParameter("username");password = request.getParameter("password");if("xingoo".equals(username)&&"123".equals(password)){session.setAttribute("loginUser",username);request.getRequestDispatcher("login_success.jsp").forward(request,response);}else{response.sendRedirect("login_failure.jsp");} %>
login_success.jsp用户登录成功界面
<%@ 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>用户登录</title> </head> <body><h1>用户登录</h1><hr>欢迎您!<%=session.getAttribute("loginUser") %> </body> </html>
login_failure.jsp用户登录失败界面
<%@ 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>用户登录</title> </head> <body><h1>用户登录</h1><hr>登录失败!<a href="login.jsp">返回登录</a> </body> </html>