String sql = "select * from userid where name='" + username + "'" ; sql += " and psw='" + password + "'" ; // 准备查询语句 ResultSet rs=stmt.executeQuery( sql );
< Input type = "submit" value = " 登陆" > < Input type = "reset" value = " 取消" > </ form > </ center > </ body > </ html >
界面如右:
6. 新建 jsp 文件 login.jsp.
<%@ page language = "java" contentType = "text/html; charset=UTF-8" pageEncoding = "UTF-8" %> <%@ page import = "java.sql.*" %> <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" > < html > < head > < meta http-equiv = "Content-Type" content = "text/html; charset=UTF-8" > < title > 验证页面 </ title > </ head > < body > <% String username = request.getParameter( "uid" ); String password = request.getParameter( "upwd" ); if (username != null && !username.equals( "" )){ try {
<%= session.getAttribute( "uname" ) %> , 欢迎您进入第二个页面！ </ body > </ html >
10. 首先在 Eclipse 中启动 Tomcat 应用服务器 , 然后启动 IE 浏览器．
10. 测试一下 ^_^ 先输入用户名，再输入密码，当然只有在 sql2000 中有的用户才是有较用户！
点击登陆后跳为下页：
欢迎进入本页面，您已经通过验证，你的用户名是 <%= session.getAttribute( "uname" ) %> < p >
< A HREF = "continue.jsp" > 您可以跳转到后续页面 </ A > </ body >
</ html > 9. 新建 continue.jsp
< Input type = "text" name = "uid" maxlenபைடு நூலகம்th = 8 style = "width:150" >< br >
< Input type = "password" name = "upwd" maxlength = 8 style = "width:150" >< br >
<%@ page language = "java" contentType = "text/html; charset=UTF-8" pageEncoding = "UTF-8" %> <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" > < html > < head > < meta http-equiv = "Content-Type" content = "text/html; charsetUTF-8" > < title > Insert title here </ title > </ head > < body > <%@ include file = "checkvalid.jsp" %>
} %> </ body > </ html >
8. 新建 main.jsp <%@ page language = "java" contentType = "text/html; charset=UTF-8" pageEncoding = "UTF-8" %> <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" > < html > < head > < meta http-equiv = "Content-Type" content = "text/html; charset=UTF-8" > < title > 主页面 </ title > </ head > < body > <%@ include file = "checkvalid.jsp" %>
/* * 连接数据库 */
Class.forName( "sun.jdbc.odbc.JdbcOdbcDriver" ); Connection con=DriverManager.getConnection( "jdbc:odbc:test" , "" , "" ); Statement stmt =con.createStatement();
实现 java web 页面的登录验证
实现 java web 页面的登录验证 本案例中的程序主要通过 java jdbc-odbc 驱动连接 sql2000 数据库 , 并依 据数据库中的用户表信息验证客户端登录请求提交的用户名和密码 . 1. sql2000 数据库中建立数据库 test..
2. 在 test 数据库中建表 userid
if ( rs.next() ){ session.setAttribute( "login" , "ok" ); // 验证通过之后，跳转到后续页面 session.setAttribute( "uname" ,username);
%> < jsp:forward page = "main.jsp" />
3. 在表中增加数据
3. 建立数据源 test
Eclipse 开发环境 4. 新建项目 4. 新建 WEB 下面的 HTML 页面 index.html.
5. 写入代码 :
<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" > < html > < head >
< meta http-equiv = "Content-Type" content = "text/html; charset=UTF-8" > < title > 系统登录 </ title > </ head > < body >
< center > < h2 > 系统登录 </ h2 > < form action = "login.jsp" method = "post" >
7. 新建 checkvalid.jsp
<%@ page language = "java" contentType = "text/html; charset=UTF-8" pageEncoding = "UTF-8" %> <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" > < html > < head > < title > 验证页面 </ title >
<% } else
out.println( " 错误的用户名和密码" ); // 验证未通过，显示错误信息 out.println( "<a href=index.html> 返回</a>" ); } catch (Exception ee){
ee.printStackTrace(); } } else { out.println( " 请先登录！" ); // 验证未通过，显示错误信息 out.println( "<a href=index.html> 返回</a>" ); } %> </ body > </ html >