用Jsp做的一个简单的登陆界面，连接Mysql，数据库名字为school，表为user。

主要分为四个Jsp界面：index.jsp登陆界面，check.jsp检验页面，main.jsp登陆成功界面，error.jsp登陆失败界面。 如下所示：

<%@ page language=\ import=\ pageEncoding=\%>

欢迎光临，请登陆

用户名字 :           用户密码 :

<%@ page language=\ import=\ pageEncoding=\%>

<%

String username = new String(request.getParameter(\).getBytes(\),\);

String password = new String(request.getParameter(\).getBytes(\),\);

session.setAttribute(\,username); Connection dbconn = null; Statement stmt = null; ResultSet rs = null;

if(username.equals(\)){ response.sendRedirect(\); } try{

String driver = \;

String url = \; String user = \;

String Password = \; Class.forName(driver);

dbconn = DriverManager.getConnection(url, user, Password);

stmt = dbconn.createStatement();

String sql1 = \* from user where username='\+username+\;

rs = stmt.executeQuery(sql1); if(rs.next()){

//String sql2 = \password='\

//rs = stmt.executeQuery(sql2);

//判断用户密码是否正确 String userpass = rs.getString(\);

if(userpass.equals(password)){

response.sendRedirect(\); }

else{

response.sendRedirect(\); } }

else{

response.sendRedirect(\);

} }catch(Exception e){ e.printStackTrace(); }

finally{

rs.close(); stmt.close(); dbconn.close(); } %>

<%@ page language=\ import=\ import=\ pageEncoding=\%>

登陆成功，<%=session.getAttribute(\)%>欢迎您！

<%

Date now = new Date(); DateFormat mediumDateFormat = DateFormat.getDateTimeInstance( DateFormat.MEDIUM, DateFormat.MEDIUM); %>

       <%out.println(mediumDateFormat.format(now));%>

<%@ page language=\ import=\ pageEncoding=\%>

登陆失败，您输入的用户名或者密码不正确！