tomcat 和jdk编译jsp问题？

Question

type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception 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)
org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:966)
org.apache.jsp.index_jsp._jspService(index_jsp.java:54)
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)
root cause java.lang.NullPointerException
com.dao.LinkDao.selectLink(LinkDao.java:117)
org.apache.jsp.topOne_jsp._jspService(topOne_jsp.java:59)
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)
org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:966)
org.apache.jsp.index_jsp._jspService(index_jsp.java:54)
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)
note The full stack trace of the root cause is available in the Apache Tomcat/5.0.30 logs.

Answer 1

空值针异常，JSP页面没有得到值。

Answer 2

晕 tomcat不已经告诉你那个地方又空指针了么？
你直接去文件里看看调用哪个变量不就OK了。。？！

Answer 3

java.lang.NullPointerException 这个是错误类型
com.dao.LinkDao.selectLink(LinkDao.java:117)  这里说明了出错的地方。
LinkDao.java文件的117行，检查一下代码。