1》验证码：产生的随机数要放到session里
2》用select top5 * from art 出错 游标状态无效：去除括号里的
stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
3》数据库连接池：虽然包含了<%@include file="conn.jsp"%>但还是要在文件里声明
<%! ResultSet rs=null;%>
<%! Statement stmt=null;%>
否则会出现 rs/stmt cannot be resolved
4》中文写入ACCESS数据库为什么是 ？？： 只要加
String title=request.getParameter("title");
title=new String(title.getBytes("ISO-8859-1"));
String neirong=request.getParameter("neirong");
neirong=new String(neirong.getBytes("ISO-8859-1"));
就OK了
5》出现错误
rs.last() An exception occurred processing JSP page
: stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE 能让记录集能够前后移动
6》错误为：
org.apache.jasper.JasperException: Unable to compile class for JSP:
An error occurred at line: 16 in the jsp file: /biyesheji/nixie/addx.jsp
String literal is not properly closed by a double-quote
13: String eno=request.getParameter("eno");
14: String wdate=request.getParameter("wdate");
15: String ano=request.getParameter("ano");
16: String sql="insert into pageinfo(num,typeid,seno,eno,wdate,ano)
17: values('"+num+"','"+typeid+"','"+seno+"','"+eno+"','"+wdate+"','"+ano+"') ";
18: addx.executeUpdate(sql);
19: try{ sqlBean db =new sqlBean();
Stacktrace:
org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:85)
org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:330)
org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:435)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:298)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:277)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:265)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:564)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:299)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
解决方法：
一行代码可以换行写，一个String的内容是不能换几行写的，写成
String sql="insert into pageinfo(num,typeid,seno,eno,wdate,ano)" +
"values('"+num+"','"+typeid+"','"+seno+"','"+eno+"','"+wdate+"','"+ano+"') ";