日期:2014-05-18  浏览次数:20808 次

org.apache.jasper.JasperException: java.lang.NullPointerException错误,求助
我是用jsp连接sqlserver2000数据库的,书上有这样一个文件,dbprogram.jsp(代码如下),是用来连接查询并显示记录的,我把他放在D:\Tomcat 6.0\webapps\ROOT这个目录下面,在浏览器中输入http://localhost:8080/dbprogram.jsp,弹出来了错误:
HTTP Status 500 - 

--------------------------------------------

type Exception report

message 

description The server encountered an internal error () that prevented it from fulfilling this request.

exception 

org.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:541)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:435)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)


root cause 

java.lang.NullPointerException
org.apache.jsp.dbprogram_jsp._jspService(dbprogram_jsp.java:116)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)


note The full stack trace of the root cause is available in the Apache Tomcat/6.0.14 logs.

在这前我已经把sql2000的驱动程序安装好了,并把里面的三个包放在了D:\Tomcat 6.0\lib这个目录下面,还在classpath中设为.;c:\program files\Microsoft SQL Server 2000 Driver for JDBC\lib\msbase.jar;c:\program files\Microsoft SQL Server 2000 Driver for JDBC\lib\msutil.jar;c:\program files\Microsoft SQL Server 2000 Driver for JDBC\lib\mssqlserver.jar 
我觉得应该没有错了,下面是那个jsp文件:
<%@ page contentType="text/html; charset=gb2312" %>
<%@ page info="database handler"%> 
<%@ page import="java.io.*"%> 
<%@ page import="java.util.*"%> 
<%@ page import="java.sql.*"%> 
<%@ page import="javax.servlet.*"%> 
<%@ page import="javax.servlet.http.*"%> 
<!--导入结束--> 
<html>
<head>
<title>数据库连接实验</title>
</head>
<body>
<% 
  String sDBDriver = "com.microsoft.jdbc.sqlserver.SQLServerDriver";  
  String sConnStr = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=pubs";// 
  Connection Con = null;
  Statement Stmt = null;
try 

  try /*加载驱动程序*/
  {
  Class.forName(sDBDriver).newInstance(); 
  }
  catch(java.lang.ClassNotFoundException e)
  { 
  out.print("Connect to Database error: " + e.getMessage());
  }