jsp错误调试

[am2000]

HTTP Status 500 -

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type Exception report

message

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:316)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:277)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:223)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)


root cause

java.lang.NullPointerException
myclass.nfjips.executeQuery(nfjips.java:72)
org.apache.jsp.index_jsp._jspService(index_jsp.java:224)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:268)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:277)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:223)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)


note The full stack trace of the root cause is available in the Apache Tomcat/5.0.22 logs.


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可能是什么原因?

[liusoft]

异常发生在myclass.nfjips.executeQuery(nfjips.java:72)

请检查这个类，而不是JSP页面

http://www.javayou.com

[lovelymaomao]

myclass.nfjips.executeQuery(nfjips.java:72)

估计是你的Connection为空~~~~myclass.nfjips 可以这么写嘛？难道nfjjips为static Statment object？？？？

[xuyang821225]

public class NullPointerException
extends RuntimeException
Thrown when an application attempts to use null in a case where an object is required. These include:

Calling the instance method of a null object.
Accessing or modifying the field of a null object.
Taking the length of null as if it were an array.
Accessing or modifying the slots of null as if it were an array.
Throwing null as if it were a Throwable value.
Applications should throw instances of this class to indicate other illegal uses of the null object.