Question

javabean连接数据库，jsp页面测试服务器为tomcat，运行jsp页面时报空指针错误该怎么解决

HTTP Status 500 - java.lang.NullPointerException
type Exception report
message java.lang.NullPointerException
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:549)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:470)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

root cause
java.lang.NullPointerException
tom.jiafei.ShowRecordByPage.show(ShowRecordByPage.java:89)
tom.jiafei.ShowRecordByPage.getPresentPageResult(ShowRecordByPage.java:78)
org.apache.jsp.showRecord_jsp._jspService(showRecord_jsp.java:117)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

Answer 1

500错误，空指针异常，是指在你的代码里使用了为空的对象。最常用的解决办法，就是把提示的错误行中所使用的对象打印出来，检查一下是否为NULL，如果是NULL，请检查一下你的代码，查找一下引起空指针的原因。祝你好运！

Answer 2

这个提示很明显啊，你debug下，断点设置在getPresentPageResult 78行和show 89行

追问

能不能帮我看下文件，我发给你？

Answer 3

http://zhidao.baidu.com/question/310457782?&oldq=1

Answer 4

找到哪句话 空指针报错 这个错是最喜欢 最简单的错