日期:2014-05-18  浏览次数:20820 次

我的jsp运行之后的异常,麻烦高手指点一下谢谢.我新手.
// <%@   page   contentType= "text/html;   charset=gb2312 "   language= "java "   import= "java.sql.* "   errorPage= " "   %>
<!DOCTYPE   html   PUBLIC   "-//W3C//DTD   XHTML   1.0   Transitional//EN "   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
<html   xmlns= "http://www.w3.org/1999/xhtml ">
<head>
<meta   http-equiv= "Content-Type "   content= "text/html;   charset=gb2312 "   />
<title> 无标题文档 </title>
</head>

<body>
<jsp:useBean   id= "sq "   scope= "session "   class= "sqlbean.sqlbean "/>
<%
ResultSet   rs=sq.executeQuery( "select   *   from   student ");
%>
<table>
<tr> <td   bgcolor= "#00FF99 "> id </td> <td   bgcolor= "#9900FF "> 姓名 </td> </tr>
<%while(rs.next()){%>
<tr>
<td   bgcolor= "#FF0000 "> <%=rs.getString( "id ")%> </td>
<td   bgcolor= "#3333FF "> <%=rs.getString( "name ")%> </td>
</tr>
<%}
rs.close();
%>
</table>
</body>
</html>
异常如下:
org.apache.jasper.JasperException
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:372)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)


root   cause  

java.lang.NullPointerException
org.apache.jsp.sql_jsp._jspService(sql_jsp.java:68)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

我感觉我的jsp没有错误啊!为什么就是出不来呢

------解决方案--------------------
1. 第一行应该没有 "// "()估计不是这个问题。
2. <jsp:useBean id= "sq " scope= "session " class= "sqlbean.sqlbean "/>
这个class用完整的路径试试。
------解决方案--------------------
把sqlbean.sqlbean的代码贴出来看看