求教 jsp代码问题！

wangym29 2006-09-20 08:49:42

请高手帮看看这段程序错到哪了！

<%@ 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.*"%>

<html>
<head>
<title>数据库连接实验</title>
</head>
<body>
<%
String sDBDriver = "sun.jdbc.odbc.JdbcOdbcDriver";
String sConnStr = "jdbc:odbc:try";//“try”的意思就是与刚才设置的数据源名对应;
Connection Con = null;
Statement Stmt = null;
try
{
try /*加载驱动程序*/
{
Class.forName(sDBDriver);
}
catch(java.lang.ClassNotFoundException e)
{
out.print("Connect to Database error: " + e.getMessage());
}
try /*建立连接*/
{
Con = DriverManager.getConnection(sConnStr,"sa","");
}
catch(SQLException e)
{
out.print(e.toString());
}

Stmt = Con.createStatement(); /*创建JDBC声明*/
String query="CREATE TABLE GUEST" + /*在数据库中创建新的表*/
"(NUM VARCHAR(32),"+
"USERNAME TEXT,"+
"CONTENT TEXT,"+
"PASSWORD INTEGER,"+
"TOTAL INTEGER,"+
"REALNAME TEXT)";
Stmt.executeUpdate(query); /*更新数据库*/
}
catch (Exception e) {}
out.println("恭喜，表连接创建成功！");
%>
<%
ResultSet RS= Stmt.executeQuery("SELECT * FROM EMPLOYEE WHERE eage<25"); /*连接到数据库中的表EMPLOYEE上*/
String tt; /**号表示选择表中所有的列*/
String link; /*若选择其中的某几列可以将*号换成列标号*/
String makeStr; /*WHERE语句表示条件选择*/
out.print("<table border=2 style=color:blue >");
while (RS.next()) {
out.print("<tr><td>");
tt = RS.getString("ename"); /*查询表中NUM字段的内容，字段内容可能使数组，默认列输出*/
out.print(tt);
out.print("</td><td>");
tt = RS.getString("esex");
out.print(tt);
out.print("</td><td>");
tt = RS.getString("eage");
out.print(tt);
out.print("</td><td>");
tt=RS.getString("egrade");
out.print(tt);
out.print("</td><td>");
}
out.print("</table>");
RS.close();
out.println("数据查询成功！");
%>
<% /*在数据库中添加数据*/
String sql="INSERT INTO EMPLOYEE VALUES ('5','aaa','m',54,'hehe')";
Stmt.executeUpdate(sql);
out.println("添加数据成功!");
%>
</body>
</html>

我运行后的界面是：

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: Exception in JSP: /dbprogram.jsp:51

48: catch (Exception e) {}
49: out.println("恭喜，表连接创建成功！");
50: %>
51: <%
52: ResultSet RS= Stmt.executeQuery("SELECT * FROM EMPLOYEE WHERE eage<25"); /*连接到数据库中的表EMPLOYEE上*/
53: String tt; /**号表示选择表中所有的列*/
54: String link; /*若选择其中的某几列可以将*号换成列标号*/

Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:504)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

root cause

java.lang.NullPointerException
org.apache.jsp.dbprogram_jsp._jspService(dbprogram_jsp.java:105)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:332)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

note The full stack trace of the root cause is available in the Apache Tomcat/5.5.17 logs.

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

Apache Tomcat/5.5.17

问题很急，在线等待，请高手帮忙！

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