An exception occurred processing JSP page 的问题

Question

HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception org.apache.jasper.JasperException: An exception occurred processing JSP page /iframe/head.jsp at line 107: <%
8: String path = request.getContextPath();
9: String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
10: List sysList=sys.getSiteInfo();
11:  
12: List affList=abc.getAllAffiche();
13: List AllnewsList=news.getAllNews();
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:524)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:435)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
root cause java.lang.NullPointerException
com.util.DBO.close(DBO.java:57)
com.bean.SystemBean.getSiteInfo(SystemBean.java:74)
org.apache.jsp.index_jsp._jspService(index_jsp.java:120)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)请各位大哥帮忙解决下这个问题，谢谢了。

Answer 1

sys ，abc ， news
 这三个你定义在那里的。 我看看怎么定义的。  

Answer 2

<%@ page language="java" import="java.util.*"  contentType="text/html;charset=gb2312" %>
<jsp:useBean id="sys" scope="page" class="com.bean.SystemBean" />
 <jsp:useBean id="cb" scope="page" class="com.bean.ComBean"/>
<jsp:useBean id="abc" scope="page" class="com.bean.AfficheBean"/>
<jsp:useBean id="news" scope="page" class="com.bean.NewsBean"/>
<jsp:useBean id="tb" scope="page" class="com.bean.HzpBean"/>是这个吗？

Answer 3

第十行List sysList=sys.getSiteInfo();
参数越界产生了空指针...

Answer 4

最终抛出异常的代码:
java.lang.NullPointerException
com.util.DBO.close(DBO.java:57)
DBO.java的第57行. 看看这个类的代码.