jsp连接mysql出错，新手求解

<%@ page language="java" contentType="text/html;charset=gb2312" %>
<%@ page import="java.sql.*,com.am.*"%>
<jsp:useBean id="dbconn" scope="application" class="com.am.OpenDB"/>
<jsp:useBean id="userlogin" scope="session" class="com.am.login" />
<html>
<head>
<title>刊物文章管理系统</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</head>
<body>
<%
 userlogin.userName=request.getParameter("txtloginName");
 userlogin.userPassword=request.getParameter("txtpassword");
userlogin.systemRole=request.getParameter("userType");
 userlogin.setConnection(dbconn.getConnection());
if (userlogin.isValidUser())
 {
 session.setAttribute("loginType",userlogin.systemRole);
if(0 == userlogin.systemRole.compareTo("0"))
{
response.sendRedirect("admin/adminManagement.jsp");
}
if(0 == userlogin.systemRole.compareTo("1"))
{
response.sendRedirect("author/articlesManagement.jsp");
}
if(0 == userlogin.systemRole.compareTo("2"))
{
response.sendRedirect("audit/auditManagement.jsp");
}
}
 else
 {
%>
<center>

登陆失败，请检查您的用户名和密码

</center>
 
 <center>
 <input type="button" name="goback" value="返回" onClick="javascript:window.history.go(-1)">
 </center>
<%
 }
%>
</body>
</html>
当访问这个页面时，就会出上面的错误，
应该是javabean出错了，因为bean中有操作库的语句

这个是openDBpackage com.am;
import java.sql.*;public class OpenDB
{

    String userName="root";
    String userPassword="root";
    private String driverName = "org.gjt.mm.mysql.Driver";
    private String url = "jdbc:mysql://localhost:3306/am";    Connection dbConn;
    public OpenDB()
    {    }
    public Connection getConnection()
    {
        try
        {
            Class.forName(driverName);
            dbConn=DriverManager.getConnection(url,userName,userPassword);
        }
        catch(Exception ex)
        {
            System.out.println(ex.toString());
            dbConn = null;
        }

        return dbConn;
    }}

Loginpackage com.am;
import java.util.*;
import java.sql.*;
import java.text.*;
public class login extends user
{


    private String strSql;
    private Connection dbConn;
    private int errNum;
    private String errDesc;
    SimpleDateFormat dateFormatter;
    public login()
    {
        super();
    strSql="";
        errNum=0;
        errDesc="";
   }   public boolean isValidUser()
   {
        strSql="select * from `users` ";
strSql=strSql + " where userName='" + userName + "'";
strSql=strSql + " and userPassword='"+ userPassword + "'";
strSql=strSql + " and systemRole= '"+systemRole+"'";
        Statement stmt=null;
        ResultSet rs=null;
        try
        {
    stmt=dbConn.createStatement();
rs =stmt.executeQuery(strSql);
            if (rs.next())
            {
                ID=rs.getLong("ID");
                userName=rs.getString("userName");
                userPassword=rs.getString("userPassword");
                name=rs.getString("name");
                company=rs.getString("company");
                depart=rs.getString("depart");
                email=rs.getString("email");
                myfields=rs.getString("myfields");
                systemRole=rs.getString("systemRole");
                createDatetime=rs.getString("createDatetime");
                tag=rs.getInt("tag");

                this.errNum=0;
                this.errDesc="";
                return true;
            }
            else
            {
                this.errNum=-1;
                this.errDesc="Not Valid User";
                return false;            } }
catch(Exception ex)
{
            this.errNum=-1;
            this.errDesc=ex.toString();
            return false; }
        finally
        {        }   }   public void  setConnection(Connection dbConn)
   {
    this.dbConn=dbConn;
   }

   private void exeSql(String strSql)
   {
    try
{
    Statement stmt=dbConn.createStatement();
stmt.executeUpdate(strSql);
            this.errNum=0;
            this.errDesc="";
}
catch(Exception ex)
{
            this.errNum=-1;
            this.errDesc=ex.toString(); }
   }    public int getErrNum()
    {
        return errNum;    }

    public String getErrDesc()
    {
        return errDesc;
    }
}

你用客户端连接一下看看是否有问题，
或者你把mysql停了，看看3306端口是否有使用？

userpackage com.am;import java.util.*;
import java.sql.*;
import java.text.*;
public class user
{    public long ID;
    public String userName;
    public String userPassword;
    public String name;
    public String company;
    public String depart;
    public String email;
    public String myfields;
    public String systemRole;
    public String createDatetime;
    public int tag;
    private String strSql;
    private Connection dbConn;
    private int errNum;
    private String errDesc;
    private SimpleDateFormat dateFormatter;
    public user()
    {
        dateFormatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        ID=0;
        userName="";
        userPassword="";
        name="";
        company="";
        depart="";
        email="";
        myfields="";
        systemRole="";
      createDatetime=dateFormatter.format(new java.util.Date());
tag=0;
    strSql="";
        dbConn=null;
        errNum=0;
        errDesc="";
   }

   public void add()
   {
        String tmpcreateDatetime;
        createDatetime=dateFormatter.format(new java.util.Date());
        strSql="insert into users ";
        strSql=strSql + "(";
        strSql=strSql + "userName,";
        strSql=strSql + "userPassword,";
        strSql=strSql + "name,";
        strSql=strSql + "company,";
        strSql=strSql + "depart,";
        strSql=strSql + "email,";
        strSql=strSql + "myfields,";
        strSql=strSql + "systemRole,";
        strSql=strSql + "createDatetime,";
        strSql=strSql + "tag";
        strSql=strSql + ") ";
strSql=strSql + "values(";
strSql=strSql + "'" + userName + "',";
strSql=strSql + "'" + userPassword + "',";
strSql=strSql + "'" + name + "',";
strSql=strSql + "'" + company + "',";
strSql=strSql + "'" + depart + "',";
strSql=strSql + "'" + email + "',";
strSql=strSql + "'" + myfields + "',";
strSql=strSql + "'" + systemRole + "',";
strSql=strSql + "'" + createDatetime + "',";
strSql=strSql + "'" + tag + "'";
strSql=strSql + ")";
exeSql(strSql);
   }
   public void update()
   {
    strSql="update users set ";
strSql=strSql + "userName=" + "'" + userName + "',";
strSql=strSql + "userPassword=" + "'" + userPassword + "',";
strSql=strSql + "name=" + "'" + name + "',";
strSql=strSql + "company=" + "'" + company + "',";
strSql=strSql + "depart=" + "'" + depart + "',";
strSql=strSql + "email=" + "'" + email + "',";
strSql=strSql + "myfields=" + "'" + myfields + "',";
strSql=strSql + "systemRole=" + "'" + systemRole + "',";
strSql=strSql + "createDatetime=" + "'" + createDatetime + "',";
strSql=strSql + "tag=" + "'" + tag + "'";
strSql=strSql + " where ID='" + ID + "'";
exeSql(strSql);   }

      public void updatekey()
      {
       strSql="update users set ";
       strSql=strSql + "userPassword=" + "'" + userPassword + "'";
       strSql=strSql + " where ID='" + ID + "'";
       exeSql(strSql);      }
   public void delete()
   {
        strSql="delete from `users` where ID='";
        strSql=strSql + this.ID + "'";
        exeSql(strSql);   }
   public void enable()
   {
        strSql="update users set tag=0 where ID='";
        strSql=strSql  + this.ID + "'";
        exeSql(strSql);   }
   public void  disable()
   {
        strSql="update users set tag=-1 where ID='";
        strSql=strSql + this.ID + "'";
        exeSql(strSql);   }
   public boolean  init()
   {
     strSql="select * from `users` where ID=";
        strSql=strSql + "'" + this.ID + "'";
        Statement stmt=null;
        ResultSet rs=null;
        try
{
    stmt=dbConn.createStatement();
rs =stmt.executeQuery(strSql);
            if (rs.next())
            {
                ID=rs.getLong("ID");
                userName=rs.getString("userName");
                userPassword=rs.getString("userPassword");
                name=rs.getString("name");
                company=rs.getString("company");
                depart=rs.getString("depart");
                email=rs.getString("email");
                myfields=rs.getString("myfields");
                systemRole=rs.getString("systemRole");
                createDatetime=rs.getString("createDatetime");
                tag=rs.getInt("tag");
                this.errNum=0;
                this.errDesc="";
                return true;
            }
            else
            {
                this.errNum=-1;
                this.errDesc="init faild!";
                return false;            } }
catch(Exception ex)
{
            this.errNum=-1;
            this.errDesc=ex.toString();
            return false; }
        finally
        {
            stmt=null;
            rs=null;
        }
   }
   public void  setConnection(Connection dbConn)
   {
    this.dbConn=dbConn;
   }

   private void exeSql(String strSql)
   {
    try
{
    Statement stmt=dbConn.createStatement();
stmt.executeUpdate(strSql);
            this.errNum=0;
            this.errDesc="";
}
catch(Exception ex)
{            this.errNum=-1;
            this.errDesc=ex.toString(); }
   }
    public int getErrNum()
    {
        return errNum;    }

    public String getErrDesc()
    {
        return errDesc;
    }
}

to yangxiao_jiang(哈哈) 将服务停掉就出现下面的错误信息java.sql.SQLException: Cannot connect to MySQL server on localhost:3306. Is ther
e a MySQL server running on the machine/port you are trying to connect to? (java
.net.ConnectException)客户端测试连接我不会，

客户端连接我已测过，出现下面的错误信息
A
5.0.27-community-nt#BdQHSIV,?QuwxsZG5sf'+遗失对主机的连接。

调试易

jsp连接mysql出错，新手求解

解决方案 »