日期:2014-05-16  浏览次数:20332 次

JSP学习笔记之实现登录小程序

1、表单页面 ---login.jsp

<%@ page language="java" import="java.util.*" pageEncoding="GB2312"%>
<%@ page contentType="text/html;charset=GB2312" %>
<html>
  <head>
    
    <title>用户登录页面</title>
    
  </head>
  <body>
  	<form action="check.jsp" method="post">
	  	<table>
	  		<tr>
	  			<td>用户名ID:</td>
	  			<td><input type="text" name="userid"></td>
	  		</tr>
	  		<tr>
	  			<td>密码:</td>
	  			<td><input type="password" name="password"></td>
	  		</tr>
	  		<tr>
	  			<td><input type="submit" value="提交"></td>
	  			<td><input type="reset" value="重置"></td>
	  		</tr>
	  	</table>
  	</form>
  </body>
</html>


2、表单处理页面---check.jsp

<%@ page language="java" import="java.util.*" pageEncoding="GB2312"%>
<%@ page contentType="text/html;charset=GB2312" %>
<%@ page import="java.sql.*" %>
<html>
  <head>
    
    <title>验证处理</title>
    
  </head>
  <body>
  	<%--
  		处理页面请求的乱码,并接收提交页面传来的参数
  	--%>
  	<%
  		request.setCharacterEncoding("gb2312");
  		String userid = request.getParameter("userid");
		String password = request.getParameter("password");
  	%>
  	<%--
		声明设置数据库的连接的变量
    --%>
    <%!
	    public static final String DBDRIVER="oracle.jdbc.driver.OracleDriver";
		public static final String DBURL="jdbc:oracle:thin:@localhost:1521:HXH";;
		public static final String DBUSER="scott";
		public static final String DBPASS="tiger";
    %>
    <%--
  		创建数据库连接对象;
  		定义数据库登录成功与否的标记flag;
  		并取得用户名和密码
  	--%>
  	<%
  		Connection conn = null;
  		PreparedStatement pstmt = null;
  		ResultSet rs = null;
  		boolean flag = false;
  	%>
  	<%--
  		加载数据库驱动程序进行数据库的连接;
  		定义连接数据库的查询语句;
  		遍历查询结果
  	--%>
  	<%
  		try{
  			Class.forName(DBDRIVER);
  			conn = DriverManager.getConnection(DBURL,DBUSER,DBPASS);
  			String sql = "select userid,name from tuser where userid=? and password=?";
  			pstmt = conn.prepareStatement(sql);
  			pstmt.setString(1,userid);
  			pstmt.setString(2,password);
  			rs = pstmt.executeQuery();
  			if(rs.next()){
  				flag=true;
  			}
  		}catch(Exception e){
  			
  		}finally{
  			try{
  				conn.close();
  			}catch(Exception e){
  				out.print(e);
  			}
  		}
  	%>
  	<%
  	if(flag){
  	%>
  		<jsp:forward page="success.jsp" />
  	<%
  		}else{
  	%>
  		<jsp:forward page="failure.jsp"></jsp:forward>
  	<%
  		}
  	%>
  	</body>
</html>


3、结果成功页面---success.jsp

 

<%@ page language="java" import="java.util.*" pageEncoding="GB2312"%>
<%@ page contentType="text/html;charset=GB2312" %>
<html>
  <head>
    
    <title>用户登录页面</title>
    
  </head>
  <body>
  	<h1>登录成功</h1>
  </body>
</html>

4、结果失败页面---failure.jsp

<%@ page language="java" import="java.util.*" pageEncoding="GB2312"%>
<%@ page contentType="text/html;charset=GB2312" %>
<html>
  <head>
    
    <title>用户登录页面</title>
    
  </head>
  <body>
  	<h1>登录失败</h1>
  </body>
</html>