jsp mysql 连接错误
老师布置的作业，用jsp连接mysql数据库。我准备了3个文件，index。jsp用于从表单中获取数据（用户名和密码），JDBConnection.java是一个javabean。check。jsp用于检验用户输入的数据（先获取传递过来的用户名和密码，然后检索数据库，做比较，进行简单的判断）。操蛋的j2ee老师，你让我们这些没学java的人情何以堪啊。。。。。
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代码：
index。jsp
- Assembly code
<%@ page language="java" import="java.util.*" pageEncoding="GBK"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> </head> <body> <form method="get" action="check.jsp"> <table> <tr><td>用户名：<input type="text" name="username" value=""></td></tr> <tr><td>密码：<input type="password" name="password" value=""></td></tr> <tr><td><input type="submit" value="提交" ></td> <td valign="top"><br></td><td valign="top"><br></td><td valign="top"><br></td><td valign="top"><br></td><td><input type="reset" value="取消" ></td></tr> </table> </form> </body></html>
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JDBConnection.java（在包yours下）的源码:
- Assembly code
package yours;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class JDBConnection{ private final String dbDriver="com.mysql.jdbc.Driver"; private final String url="jdbc:mysql://localhost:3306/char1_2"; private final String userName="root"; private final String password="1991016"; private Connection con; public JDBConnection() { try{ Class.forName(dbDriver).newInstance(); }catch (Exception e) { System.out.println("未能成功加载驱动!"); } } public boolean createConnection() { try{ con=DriverManager.getConnection(url,userName,password); con.setAutoCommit(true); }catch(SQLException e) { return false; } return true; } public ResultSet executeQuery(String sql) { ResultSet rs; try { if(con==null) createConnection(); Statement stmt =con.createStatement(); rs=stmt.executeQuery(sql); }catch(Exception e) { return null; } return rs; } public void closeConnection() { if(con!=null) { try{ con.close(); }catch(SQLException e) { } } }}
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- Assembly code
<%@ page language="java" import="java.util.*" pageEncoding="GBK"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>My JSP 'check.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body><%@ page import="java.sql.*" %> <jsp:useBean id="mysql" scope="page" class="yours.JDBConnection"/><%String username=new String(request.getParameter("username"));//接收传递过来的用户名String password=new String(request.getParameter("password"));//接收传递过来的密码String sql="select * from table1";ResultSet rs=null;mysql.createConnection();rs=mysql.executeQuery(sql);String usr1=null;//获取数据库中的用户名String passwd1=null;//获取用户名中的密码boolean flag=false;while(rs.next()){usr1=rs.getString("username");passwd1=rs.getString("password");if(usr1==username&&passwd1==password){out.println("欢迎你，用户："+usr1.toString());flag=true;break;//找到记录就跳出循环//}}if(flag)out.println("没找到你的用户名，"+username.toString()+"没有注册！");rs.close();mysql.closeConnection(); %> </body></html>但是始终无法得到结果，他们说驱动有问题，想请大虾帮忙解惑。。。
[解决办法]
[解决办法]
数据库连接提示啥错误贴出来
[解决办法]
yexuxitongwenti
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楼主，你的mysql数据库驱动lib包在哪儿？你确定你项目中有这个类么com.mysql.jdbc.Driver？木有的话，去oracle官网下了lib包，http://dev.mysql.com/downloads/connector/j/。然后在项目的build path里面把驱动包加进去。
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有什么错误的提示么？代码看着是没有问题的
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[解决办法]
把后台信息发出来看看先
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这个问题建议你看下tomcat安装目录的log目录下的stdout文件，看看System.out.println都输出了什么。如果是"未能成功加载驱动!"，那么就是驱动问题，保险一点，就放到web-inf下面去。多用日志做调试，看看代码走到哪里了，哪里有错，这个学会了很重要。
j2ee就是个很抽像的东西，不要去管它。光靠老师讲的没用，要学还得自己买书认真看，而且以后你也不一定做这个行业。如果真的要做BS类的开发，先看java的基本教程，学习一下怎么用面向对象思考问题。然后可以学习一下spring，hibernate和struts2，另外基本的html，css，javascritp也要会。