求助：jsp异常问题

来源：百度知道 编辑：UC知道 时间：2024/05/31 16:10:54
exception:
org.apache.jasper.JasperException: Exception in JSP: /index.jsp:16

13: <form method="post" action="vote.jsp">
14: <%
15: ResultSet rs=db.executeQuery("select * from vote");
16: while(rs.next()){
17: out.println("<tr>");
18: //设置单选按纽的值为当前投票项的id号
19: out.println("<td><input type='radio' name='id' value='"+rs.getString("id")+"'>");

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.NullPointerEx

dbBean.DBBean里面有这个方法executeQuery("select * from vote");？

“db.executeQuery("select * from vote");”没有获得ResultSet。

“db.executeQuery("select * from vote");”没有获得ResultSet。

把db改成java代码,不要用标签.

db 对象处理一下