java.sql.SQLException: [Microsoft][ODBC SQL Server Driver]无效的描述符索引

下面是错误代码。。
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java.sql.SQLException: [Microsoft][ODBC SQL Server Driver]连接占线导致另一个 hstmt
at sun.jdbc.odbc.JdbcOdbc.createSQLException(Unknown Source)
at sun.jdbc.odbc.JdbcOdbc.standardError(Unknown Source)
at sun.jdbc.odbc.JdbcOdbc.SQLExecute(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcPreparedStatement.execute(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcPreparedStatement.executeUpdate(Unknown Source)
at com.dong.login.ServerThread.run(Server.java:60)
java.sql.SQLException: [Microsoft][ODBC SQL Server Driver]连接占线导致另一个 hstmt
at sun.jdbc.odbc.JdbcOdbc.createSQLException(Unknown Source)
at sun.jdbc.odbc.JdbcOdbc.standardError(Unknown Source)
at sun.jdbc.odbc.JdbcOdbc.SQLExecute(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcPreparedStatement.execute(Unknown Source)
at sun.jdbc.odbc.JdbcOdbcPreparedStatement.executeUpdate(Unknown Source)
at com.dong.login.ServerThread.run(Server.java:60)
Close Socket...
end thread...
//----------------------------------
//下面是源程序代码
//=-------------------------------
package com.dong.login;import java.io.*;
import java.net.*;
import java.sql.*;
import java.util.Vector;
class ServerThread extends Thread{//继承线程
   private Socket socket;//定义套接口
   private BufferedReader in;//定义输入流
   private PrintWriter out;//定义输出流
   int no;//定义申请的jicq号码   public ServerThread(Socket s) throws IOException {//线程构造函数
       socket=s;//取得传递参数
       in=new BufferedReader(new InputStreamReader(socket.getInputStream()));//创建输入流
       out=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);//创建输出流
       start();//启动线程
   }   public void run(){//线程监听函数
   try{
     while(true){
            String str=in.readLine();//取得输入字符串
            if(str.equals("end")){System.out.println("receive 'end'");break;}//如果是结束就关闭连接
            else if(str.equals("login")) {//如果是登录
                try{
                    System.out.println("login");
                    Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");//连接数据库
                    Connection c=DriverManager.getConnection("jdbc:odbc:jicq","sa","sa");
                    String sql="select nickname,password,ip,status,pic,email,info,place,sex from icq where icqno=?";
                           //准备从数据库选择呢称和密码
                    PreparedStatement prepare=c.prepareCall(sql);//设定数据库查寻条件
                    String icqno=in.readLine();
                    int g=Integer.parseInt(icqno);//取得输入的jicq号码
                    System.out.println("the icpno login:"+icqno);
                    String passwd=in.readLine().trim();//取得输入的密码
                    System.out.println("the password received:"+passwd);
                    prepare.clearParameters();
                    prepare.setInt(1,g);//设定参数
                    ResultSet r=prepare.executeQuery();//执行数据库查寻
                    if(r.next()){//以下比较输入的号码于密码是否相同
                      String pass = r.getString("password").trim();
                      System.out.println("the password from database:" + pass);
                      //如果相同就告诉客户ok
                      //并且更新数据库用户为在线
                      
                      //以及注册用户的ip 地址
                      if(passwd.regionMatches(0,pass,0,pass.length()))
                       {
                      //if (passwd.equals(pass)) {
                        System.out.println("password matched successfully");
                        //out.println("ok");
                       // System.out.println("send 'OK' to client");
                        //*************register ipaddress
                        String setip = "update icq set ip=? where icqno=?";
                        PreparedStatement prest = c.prepareCall(setip);
                        prest.clearParameters();
                        prest.setString(1, socket.getInetAddress().getHostAddress());
                        prest.setInt(2, g); //g为取得输入的jicq号码
                        int set = prest.executeUpdate();//程序走到这个地方就已经出现了占线（hstmt）错误                        System.out.println("update IP Status:"+set);
                        //*************ipaddress
                         //set status online
                        String status = "update icq set status=1 where icqno=?";
                        PreparedStatement prest2 = c.prepareCall(status);
                        prest2.clearParameters();
                        prest2.setInt(1, g); //g为取得输入的jicq号码
                        int set2 = prest2.executeUpdate();
                        System.out.println("set the icqno status online(1):"+set2);
                        //set online
                        out.println("ok");
                         System.out.println("send 'OK' to client,login finished");
                        //开始发送登录者的个人信息
                        out.println(r.getString("nickname"));
                        out.println(r.getString("ip"));
                        out.println(r.getString("status"));
                        out.println(r.getString("pic"));
                        out.println(r.getString("email"));
                        out.println(r.getString("info"));
                        out.println(r.getString("place"));
                        out.println(r.getString("sex"));
                        System.out.println("Send the loginer's info successfully");
                      }
                      //否者告诉客户失败
                      else {
                        System.out.println("password error!");
                        out.println("pwderror");///////////////////////////////////////////////////// send false
                        r.close();
                        c.close();
                      }
                    }
                    else{
                      System.out.println("the icqno is wrong,not in the db!");
                      out.println("usererror");/////////////////////////////////////////////////////// send false
                      System.out.println("send false");
                      r.close();
                      c.close();
                    }
                 }catch (Exception e){
                       out.println("false");
                       e.printStackTrace();}
                socket.close();break;
                }//end login
             //登录结束
  //处理上线结束
   System.out.println("finished:"+str);
  } //end while  //处理str="end"
  System.out.println("Close Socket...");
  this.socket.close();//changed:add
  System.out.println("end thread...");
  this.yield();//changed:add
 }
 catch(IOException e){}//捕或异常
      finally {try{socket.close();}
                     catch(IOException e){}
  }//end try
 }//end run
}//end class ServerThread
//主服务器类
public class Server{
public static void main(String args[])throws IOException{
   ServerSocket s=new ServerSocket(10000);//在10000端口创建套接口
   System.out.println("Server start.."+s);
   try{
     while(true){
       Socket socket=s.accept();//无限监听客户的请求
       System.out.println("Connection accept:"+socket+"(new Socket created)");
       System.out.println("HOST:"+socket.getInetAddress().getHostAddress());
       try{new ServerThread(socket);//创建新线程
    }
       catch(IOException e){
         System.out.println(e.getMessage());
         socket.close();}
        }
    }finally{s.close();}//捕或异常
  }//end main
}//服务器程序结束
//--------------------------------
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