请求各位的帮忙报错为返回空指针

wlyep1985 2008-04-29 10:03:28

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312"%>
<%@ page import="java.sql.*" %>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>提供者信息查询</title>
</head>
<body>
<%
Connection conn=null;
Statement stmt=null;
ResultSet rs=null;
String strSQL="";
int PageSize=3;
int Page=1;
int totalPage=1;
int totalrecord=0;
String url = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=健康管理信息系统";
String user ="sa";
String password = "sa";
try
{
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
}
catch(ClassNotFoundException ce)
{
out.println(ce.getMessage());
}
try
{
conn=DriverManager.getConnection( url, user, password );
stmt=conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.TYPE_FORWARD_ONLY);
//算出总行数
//strSQL="select count(*) as recordcount from provider";
rs=stmt.executeQuery("select count(*) as recordcount from provider");
if(rs.next())
totalrecord=rs.getInt("recordcount");
//输出记录
//strSQL="select * from provider";
rs=stmt.executeQuery("select * from provider");
if(totalrecord%PageSize==0)//当前页面的整数倍
totalPage=totalrecord/PageSize;
else//如果最后还空余一页
totalPage=(int)Math.floor(totalrecord/PageSize)+1;
if(totalPage==0)
totalPage=1;
if(request.getParameter("Page")==null||request.getParameter("Page").equals(""));
Page=1;
try
{
Page=Integer.parseInt(request.getParameter("Page"));
}
catch(java.lang.NumberFormatException e)
{
Page=1;
}
if(Page<1) Page=1;
if(Page>totalPage) Page=totalPage;
rs.absolute((Page-1)*PageSize+1);
out.println("<table BORDER='1'>");
for( int iPage=1;iPage<=PageSize;iPage++)
{
out.print("<TR><TD>"+rs.getString("providerid")+"</TD>");
out.print("<TD><a href='view.jsp?id="+rs.getString("providerid")+"'>"+rs.getString("providername")+"</a></TD>");
out.print("<TD>"+rs.getString("providername")+"</TD>");
out.print("<TD>"+rs.getString("provideraddr")+"</TD>");
out.print("<TD>"+rs.getString("providertel")+"</TD></TR>");
out.print("------------>");
if(!rs.next()) break;
}
out.println("</table>");
}
catch(SQLException e)
{
System.out.println((e.getMessage()));
}
finally
{
stmt.close();
conn.close();
}
%>
<FORM action="provider.jsp" method=GET>
<%
if(Page!=1)
{
out.print("<a href=provider.jsp?Page=1>第一页</a>");
out.print("<a href=provider.jsp?Page="+(Page-1)+">;上一页</a>");
}
if(Page!=totalPage)
{
out.print("<a href=provider.jsp?Page="+(Page+1)+">;下一页</a>");
out.print("<a href=provider.jsp?Page="+totalPage+">最后一页</a>");
}
%>
<br>输入页数:<input TYPE="TEXT" Name="Page" SIZE="3">
页数:<font COLOR="Red"><%=Page%>/<%= totalPage %></font>
</FORM>
</body>
</html>

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