java.lang.NullPointerException希望各位大佬帮帮忙，找了半天真的不晓得咋弄了

程序代码

HTTP Status 500 – Internal Server Error
Type Exception Report

Message java.lang.NullPointerException

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

org.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:565)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:481)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:385)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:329)
javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

java.lang.NullPointerException
service.userservice.valiUser(userservice.java:18)
org.apache.jsp.validate_jsp._jspService(validate_jsp.java:139)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:443)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:385)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:329)
javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Note The full stack trace of the root cause is available in the server logs.

Apache Tomcat/8.5.20

报错提示在这:service.userservice.valiUser(userservice.java:18),你应该去valiUser加断点调试,

调用useruserservice.valiUser方法报错 去userservice第18行加断点调试。

先看看你的useruserservice.valiUser方法传回去的user对象有没有实际值嘛，或者是看看valiUser()方法有没有被调用到，一步步分析，这样才可以增加对调试代码的熟练度！！！