编译下列程序连接数据库出现错误,帮忙看一下,请各位高手帮忙!!!具体如何解决!!
buybook.java
//订购页面使用的bean
package ToLineBook;
import java.sql.*;
public class BuyBook{
 long id=0;
 String order_number,book_name;
 String serverName = "localhost";
 String sConnStr = "jdbc:microsoft:sqlserver://locahost:1433;DatabaseName=xf";
 Connection con;
 Statement sql;
 ResultSet rs;
 public BuyBook()
 {
  //加载驱动器
  try{Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");}
        catch(ClassNotFoundException e){}
   }
  //设置属性值,获取属性值的方的方法.
  public void setId(long n)
  {
   id=n;
   }
   public long getId()
   {
    return id;
    }
   public void setOrder_number(String number)
    {
        order_number=number;
     }
    public String getOrder_number()
    { 
      return order_number;
      }
    public void setBook_name(String name)
    {
     book_name=name;
     }
    public String getBook_name()
    { 
      return book_name;
      }
   //通过id查询图书列表
   public StringBuffer getMessageBuybook_id()
   {
    StringBuffer buffer=new StringBuffer();
    try{
     con=DriverManager.getConnection(sConnStr,"sa","xf");
     sql=con.createStatement();
     String condition="SELECT*FROM bookWHERE id="+id;
     rs=sql.executeQuery(condition);
     buffer.append("<Table Border><font size=1>");
     buffer.append("<TR>");
     buffer.append("<TH wodth=50>"+"<font size=1>"+"id"+"</font>");
        buffer.append("<TH wodth=50>"+"<font size=1>"+"订购号"+"</font>");
        buffer.append("<TH wodth=50>"+"<font size=1>"+"书名"+"</font>");
        buffer.append("<TH wodth=50>"+"<font size=1>"+"作者"+"</font>");
        buffer.append("<TH wodth=50>"+"<font size=1>"+"出版社"+"</font>");
        buffer.append("<TH wodth=50>"+"<font size=1>"+"出版时间"+"</font>");
        buffer.append("<TH wodth=50>"+"<font size=1>"+"单价"+"</font>");
        buffer.append("<TH wodth=50>"+"<font size=1>"+"类别"+"</font>");
       buffer.append("</TR>");
        while(rs.next())
        {
         order_number=rs.getString(2);
         book_name=rs.getString(3);
         String 作者=rs.getString(4);
         String 出版社=rs.getString(5);
            Date 出版时间=rs.getDate(6);
         String 单价=rs.getString("price");
         String 类别=rs.getString("category");
         buffer.append("<TR>");
         buffer.append("<TD>"+"<font size=1>"+rs.getLong(1)+"</font>");
         buffer.append("<TD>"+"<font size=1>"+order_number+"</font>");
         buffer.append("<TD>"+"<font size=1>"+book_name+"</font>");
         buffer.append("<TD>"+"<font size=1>"+作者+"</font>");
         buffer.append("<TD>"+"<font size=1>"+出版社+"</font>");
         buffer.append("<TD>"+"<font size=1>"+出版时间+"</font>");
         buffer.append("<TD>"+"<font size=1>"+单价+"</font>");
         buffer.append("<TD>"+"<font size=1>"+类别+"</font>");
         buffer.append("</TR>");
         }
         buffer.append("</Table>");
         buffer.append("</font>");
         con.close();
         return buffer;
         }
         catch(SQLException e)
         {
          return buffer;
          }
         
         }
        }
出现以下异常情况!!!!!!!!!!!!!!!!!!
exception 
javax.servlet.ServletException: com/microsoft/jdbc/base/BaseDriver
 at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:471)
 at org.apache.jsp.buybook$jsp._jspService(buybook$jsp.java:355)
 at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:107)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
 at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:201)
 at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:381)
 at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:473)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
 at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:243)
 at org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:566)
 at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
 at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
root cause 
java.lang.NoClassDefFoundError: com/microsoft/jdbc/base/BaseDriver
 at java.lang.ClassLoader.defineClass0(Native Method)
 at java.lang.ClassLoader.defineClass(ClassLoader.java:537)
 at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:123)
 at java.net.URLClassLoader.defineClass(URLClassLoader.java:251)
 at java.net.URLClassLoader.access$100(URLClassLoader.java:55)
 at java.net.URLClassLoader$1.run(URLClassLoader.java:194)
 at java.security.AccessController.doPrivileged(Native Method)
 at java.net.URLClassLoader.findClass(URLClassLoader.java:187)
 at org.apache.catalina.loader.StandardClassLoader.findClass(StandardClassLoader.java:674)
 at org.apache.catalina.loader.StandardClassLoader.loadClass(StandardClassLoader.java:1093)
 at org.apache.catalina.loader.StandardClassLoader.loadClass(StandardClassLoader.java:992)
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1392)
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1254)
 at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:302)
 at java.lang.Class.forName0(Native Method)
 at java.lang.Class.forName(Class.java:141)
 at ToLineBook.Login.(Login.java:20)
 at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
 at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
 at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
 at java.lang.reflect.Constructor.newInstance(Constructor.java:274)
 at java.lang.Class.newInstance0(Class.java:308)
 at java.lang.Class.newInstance(Class.java:261)
 at java.beans.Beans.instantiate(Beans.java:204)
 at java.beans.Beans.instantiate(Beans.java:48)
 at org.apache.jsp.buybook$jsp._jspService(buybook$jsp.java:101)
 at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:107)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
 at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.java:201)
 at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:381)
 at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:473)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter



 
											





 
	    

 
	