什么错误。。我做了个链接点下跳到adduser.jsp为什么?

来源:百度知道 编辑:UC知道 时间:2024/06/17 20:49:45
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:370)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:291)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:241)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

root cause

java.lang.NullPointerException
org.apache.jsp.adduser_jsp._jspService(org.apache.jsp.adduser_jsp:49)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletW

空指针异常,把跳转那部分代码贴出来
adduser.jsp里面
String message = session.getAttribute("message").toString();
改成
String message=request.getSession.getAttribute("message");

空指针错误

String message = session.getAttribute("message").toString();

你最好判断下为不为空 后面不用+TO.STRING();
会出错 你再试试吧 不成把问题补充下

没有获得传参的值,出现空指针异常! 很常见的问题!