问题描述
- jsp代码在tomcat部署提示错误500
-
HTTP Status 500 -type Exception report
message
description The server encountered an internal error that prevented it from fulfilling this request.
exception
java.lang.NullPointerException
cn.edu.jstu.jsjxy.fbh.dao.impl.UserDaoImpl.getUserByName(UserDaoImpl.java:15)
cn.edu.jstu.jsjxy.fbh.servlet.LoginServlet.doPost(LoginServlet.java:25)
javax.servlet.http.HttpServlet.service(HttpServlet.java:643)
javax.servlet.http.HttpServlet.service(HttpServlet.java:723)
cn.edu.jstu.jsjxy.fbh.filter.AuthorityFilter.doFilter(AuthorityFilter.java:33)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.44 logs.Apache Tomcat/6.0.44
解决方案
java.lang.NullPointerException这这句话可以看出应该是空指针,cn.edu.jstu.jsjxy.fbh.dao.impl.UserDaoImpl.getUserByName(UserDaoImpl.java:15)在传递参数时,存在空值的参数
解决方案二:
cn.edu.jstu.jsjxy.fbh.dao.impl.UserDaoImpl.getUserByName(UserDaoImpl.java:15)
getUserByName方法里面有对象为null。
解决方案三:
具体讲哪里,是将不出来的,必须你进去调试看看啊,debug
解决方案四:
传递给DAO的对象的值是null,查查IoC配置