<%@ 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>登录页</title> </head> <body> <form action="yanzheng.jsp" method="post"> 用户：<input type="text" name="userid" width=30 /> 密码：<input type="text" name="password" width=30 /> <br> <input type="submit" value="提交" /> </form> </body> </html>
<%@ 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>登录验证页面</title> </head> <body> <% String strUserid = request.getParameter("userid"); String strPW = request.getParameter("password"); if(strUserid == null || strUserid.trim().length() == 0) //trim() 去掉空格 { response.sendRedirect("massage.jsp?msgid=1"); //跳转到massage.jsp 文件中的 msgid=1 } else if(strPW == null || strPW.trim().length() == 0) //trim() 去掉空格 { response.sendRedirect("massage.jsp?msgid=2"); } else { //查找用户信息 String strUID = "zhangsan"; String strP = "123456"; if (strUserid.equals(strUID)) //找到账户 { if(strPW.equals(strP)) { response.sendRedirect("massage.jsp?msgid=3"); } else { response.sendRedirect("massage.jsp?msgid=4"); } } else { response.sendRedirect("massage.jsp?msgid=5"); } } %> </body> </html>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ page import="java.util.*" %> <!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>消息页面</title> </head> <body> <% String strMsgID = request.getParameter("msgid"); if(strMsgID == null || strMsgID.trim().length() == 0)//如果只用后面的 如果放入一个空值，会造成空指针异常，会报错 { out.print("请正确传递信息"); } else { int iMsgid = Integer.parseInt(strMsgID); switch(iMsgid) //当错误信息为1时 输出一句话 { case 1: out.print("请输入用户代码！"); break; case 2: out.print("请输入密码！"); break; case 3: out.print("登陆成功！"); break; case 4: out.print("密码输入错误！"); break; case 5: out.print("用户不存在！"); break; default: out.print("传递的msgid错误"); } } response.setHeader("refresh","3;URL=login.jsp"); %> </body> </html>