小弟我是用JSP连接MS Sql Server 2005数据库报错

package wuliu;import java.sql.*;public class conndata {Connection conn=null;ResultSet rs=null;  Statement st=null;  boolean n=false;  String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver";   //加载JDBC驱动  String dbURL = "jdbc:sqlserver://localhost; DatabaseName=DB_WuLiu";   //连接服务器和数据库test String userName = "sa";   //默认用户名 String userPwd = "";   //密码  public conndata() {            try {                Class.forName(driverName);                conn = DriverManager.getConnection(dbURL, userName, userPwd);                System.out.println("Connection Successful!");   //如果连接成功 控制台输出Connection Successful!            } catch (Exception e) {                 e.printStackTrace();            }  }  public ResultSet executeQuery(String sql)  {    try    {     conn=DriverManager.getConnection(dbURL, userName, userPwd);//这里报错     st=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);     rs=st.executeQuery(sql);    }catch(SQLException e)    {      e.printStackTrace();      System.out.println("Query Exception");      // TODO Auto-generated catch block    }return rs;  }  public boolean executeUpdata(String sql)  {  try  {    conn=DriverManager.getConnection(dbURL, userName, userPwd);  st=conn.createStatement();  int m=st.executeUpdate(sql);  n=true;  }catch(Exception e)  {    n=false;    e.printStackTrace();    System.out.print("Updata Exception");  }  return n;  }  public  boolean executeInsert(String sql)  {    try    {      conn=DriverManager.getConnection(dbURL, userName, userPwd);    st=conn.createStatement();    st.executeUpdate(sql);    n=true;   }catch(Exception ex)    {      n=false;     ex.printStackTrace();     System.out.println("Insert Exception");    }return n;  }  public boolean executeDelete(String sql)  {  try  {    conn=DriverManager.getConnection(dbURL, userName, userPwd);  st=conn.createStatement();  st.executeUpdate(sql);   n=true;  }  catch(Exception e)  {    n=false;    e.printStackTrace();    System.out.println("Delete exception");  }  return n;  }  public void closeConn()  {  try  {  conn.close();  }catch(Exception e)  {e.printStackTrace();}  }  public void closeStatement()  {  try  {  st.close();  }catch(Exception e)  {e.printStackTrace();}  }}