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  • JavaEE连接数据库练习

    登录端

    <%@ 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>Insert title here</title>
    </head>
    <body>
    <form action="Check2.jsp" method="post">
    
    卡号:<input type="text" name="cardid1"><br>
    密码:<input type="password" name="password1"><br>
    
    <input type="submit" value="登录">
    
    </form>>
    
    </body>
    </html>

    连接请求端

    <%@page import="com.web.cardDAO"%>
    <%@ 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>Insert title here</title>
    </head>
    <body>
    <%
    String cardid=request.getParameter("cardid1");
    String password=request.getParameter("password1");
    if(cardid==null||password==null||cardid.equals("") || password.equals(""))
    {
        out.write("请正确登录系统");
    }
    else
    {
        //检查登录信息
        cardDAO cd=new cardDAO();
        if(cd.checklogin(cardid, password))
        {
            out.write("登录成功");
        }
        else
        {
            out.write("登录失败");
        }
    }
    
    %>
    </body>
    </html>

    Java代码类

    package com.web;
    
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.ResultSet;
    import java.sql.SQLException;
    
    import com.mchange.v2.c3p0.ComboPooledDataSource;
    
    public class cardDAO {
    
    	ComboPooledDataSource cpd=new ComboPooledDataSource("helloc3p0");
    	
    
    	public boolean checklogin(String cardid,String password)
    	{
    		boolean boo=false;
    		try {
    			Connection conn=cpd.getConnection();
    			PreparedStatement ps=conn.prepareStatement(
    					"select * from bank where ba_card=? and ba_password=?");
    			ps.setString(1, cardid);
    			ps.setString(2, password);
    			
    			ResultSet rs=ps.executeQuery();
    			
    			boo=rs.next();
    			
    			rs.close();
    			ps.close();
    			conn.close();
    			cpd.close();
    			
    		} catch (SQLException e) {
    			// TODO 自动生成的 catch 块
    			e.printStackTrace();
    		}
    		
    		
    		
    		return boo;
    	}
    }
    

      

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  • 原文地址:https://www.cnblogs.com/tfl-511/p/6010491.html
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