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;
	}
}

  

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