无法写入数据库，求大神帮忙解决啊，急急急，感激不尽啊！！！！！！！！

package com.servlet;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
import com.Bean.*;

public class addaction extends HttpServlet
{
public void doPost(HttpServletRequest request,HttpServletResponse response)
throws IOException,ServletException
{
response.setContentType("text/html;charset=gb2312");
request.setCharacterEncoding("GBK");
PrintWriter out=response.getWriter();

    boolean flag=false;

    String gdbID ,gname,gpricestr,gnumstr,gmaker,gintro;

    gdbID=request.getParameter("gdbID");
    gname=request.getParameter("gname");
    gpricestr=request.getParameter("gprice");
    gnumstr=request.getParameter("gnum");
    gmaker=request.getParameter("gmaker");
    gintro=request.getParameter("gintro");

    System.out.println(gdbID);
    System.out.println(gname);
    System.out.println(gpricestr);
    System.out.println(gnumstr);
    System.out.println(gmaker);
    System.out.println(gintro);



    int gprice=Integer.parseInt(gpricestr);
    int gnum=Integer.parseInt(gnumstr);
    dbconn dbcon=new dbconn();

    String insertStr="insert into goodsInfo(gdbID,gname,gprice,gnum,gmaker,gintro) values";
    insertStr=insertStr+"('"+gdbID+"',";
    insertStr=insertStr+"('"+gname+"',";
    insertStr=insertStr+""+gprice+",";
    insertStr=insertStr+""+gnum+",";
    insertStr=insertStr+"'"+gmaker+"',";
    insertStr=insertStr+"'"+gintro+"')";

    //out.println(insertStr);
    try
    {
        flag=dbcon.executeUpdate(insertStr);
        dbcon.destory();
    }
    catch(Exception e)
    {
        out.println(e.getMessage());
    }
    if(flag)
    {
        out.println("<script language=\"javascript\">alert(\"添加成功\");window.history.go(-1);</script>");
        /*getServletConfig().getServletContext().getRequestDispatcher("/listaction").forward(request,response);*/

    }
    else
    {
        getServletConfig().getServletContext().getRequestDispatcher("/error.jsp").forward(request,response);

    }
}

}

在
flag=dbcon.executeUpdate(insertStr);
下断点，看拼接的sql是否正确，参数、参数类型。
out.println(e.getMessage());
是否输出错误信息。

你的DBCON和log呢？这样贴出来谁知道

package com.Bean;
import java.sql.*;
import javax.sql.*;
import java.util.*;

public class dbconn
{
String url="jdbc:mysql://localhost:3306/gwst"; // 定义mysql数据库url；
Connection conn=null; //定义连接
Statement stmt=null;

ResultSet rs=null; //定义结果集
ResultSetMetaData meta=null;

Hashtable ht=null; // 定义hashtable集合，用来存储查询结果
ArrayList al=null;
String userName="root";  //定义mysql数据库的用户名及密码
String userPassword="18202430419";

public dbconn(String dbName)
{

    try
    {
        Class.forName("com.mysql.jdbc.Driver");
        conn=DriverManager.getConnection(url+dbName,userName,userPassword);
    }
    catch(ClassNotFoundException e)
    {
        System.out.println("类没有找到"+e.getMessage());
    }
    catch(SQLException e)
    {
        System.out.println("没有连接成功");
    }
}

public dbconn()
{
    try
    {
        Class.forName("com.mysql.jdbc.Driver");
        conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/gwxt",userName,userPassword);
    }
    catch(ClassNotFoundException e)
    {
        System.out.println("类没有找到"+e.getMessage());
    }
    catch(SQLException e)
    {
        System.out.println("没有连接成功");
    }
}

public ArrayList executeQuery(String sql)
{

    try
    {
        al=new ArrayList();

        stmt=conn.createStatement();

        rs=stmt.executeQuery(sql);

        meta=rs.getMetaData();

        int colCount=meta.getColumnCount();

        //System.out.println(colCount);

        while(rs.next())
        {

            ht=new Hashtable();
            for(int i=1;i<=colCount;i++)
            {
                ht.put(meta.getColumnLabel(i),rs.getObject(i));
            }

            al.add(ht);
        }



    }
    catch(SQLException ex)
    {
        System.out.println("查询出错"+ex.getMessage());
    }
    return al;
}
public boolean executeUpdate(String sql)
{
    boolean flag=false;
    try
    {

        stmt=conn.createStatement();
        stmt.executeUpdate(sql);
        System.out.println("更新成功");
        flag=true;
    }
    catch(SQLException up)
    {
        System.out.println("更新数据库发生错误");

    }

    return flag;
}
public void destory()
{
    try
    {
        if(rs!=null)
        {
            rs.close();
        }
        if(stmt!=null)
        {
            stmt.close();
        }
        if(conn!=null)
        {
            conn.close();
        }

        rs=null;
        stmt=null;
        conn=null;
    }
    catch(Exception close)
    {
        System.out.println("关闭时发生错误");
    }
}

ackage com.Bean;
import java.sql.*;
import java.util.*;
import com.Bean.*;
public class loginbean
{
dbconn dbuser=null;

public loginbean()
{
    dbuser=new dbconn();
}

public  boolean checkUser(String user,String pwd,String db)
{
    boolean flag=false;

    ArrayList aluser=null;

    if(db.equals("managerInfo"))
    {
        aluser=dbuser.executeQuery("select * from managerInfo where managID='"+user+"'");
    }

    else if(db.equals("buyerInfo"))
    {
        aluser=dbuser.executeQuery("select * from buyerInfo where regname='"+user+"'");

    }
    dbuser.destory();
    if(aluser.size()!=0)
    {
        Hashtable htuser=(Hashtable)aluser.get(0);

        System.out.println(htuser.get("psw"));
        System.out.println(pwd);
        if(htuser.get("psw").equals(pwd))
        {
            flag=true;
        }

    }
    else
    {
        flag=false;
    }


    return flag;
}

}

不知具体报错信息是什么，但是我发现楼主的代码：

   insertStr=insertStr+"('"+gdbID+"',";
    insertStr=insertStr+"('"+gname+"',";
    insertStr=insertStr+""+gprice+",";
    insertStr=insertStr+""+gnum+",";
    insertStr=insertStr+"'"+gmaker+"',";
    insertStr=insertStr+"'"+gintro+"')";

在用字符串拼接的方式构建sql语句的时候多拼接了一个小括号……………………