Question

javaweb中java.lang.NullPointerException错误

type Exception report

message

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:548)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:471)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:389)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

root cause java.lang.NullPointerException
org.apache.jsp.detail_jsp._jspService(detail_jsp.java:99)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:433)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:389)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722) 有哪位同志可以帮忙解决啊，急着交作业呢，就是这个错误，也不知道从哪儿改。拜托拜托！！

Answer 1

从错误信息来看,空指针异常报在detail.jsp这个页面上org.apache.jsp.detail_jsp._jspService(detail_jsp.java:99)

你在jsp页面的行号上双击可以debug这个jsp,按F6单步执行,你仔细看看执行到哪儿的时候报错了..
应该是在99行附近..你仔细找找.

或者把99行附近的代码贴出来,我帮你看看

Answer 2

从错误信息来看,空指针异常报在detail.jsp这个页面上org.apache.jsp.detail_jsp._jspService(detail_jsp.java:99)

你在jsp页面的行号上双击可以debug这个jsp,按F6单步执行,你仔细看看执行到哪儿的时候报错了..
应该是在99行附近..你仔细找找.

Answer 3

空值指向错误，贴出源码，这看不出来

追问

源码有好多，不知道给您那些呢