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HTTP Status 500 - --------------------------------------------------------------------------------type Exception reportmessage 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:486)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:416)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1085)
org.apache.struts.tiles.TilesRequestProcessor.doForward(TilesRequestProcessor.java:263)
org.apache.struts.tiles.TilesRequestProcessor.processTilesDefinition(TilesRequestProcessor.java:239)
org.apache.struts.tiles.TilesRequestProcessor.processForwardConfig(TilesRequestProcessor.java:302)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:241)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
com.xxxx.xxxx.pubutil.PubUtilAuthenticateFilter.doFilter(PubUtilAuthenticateFilter.java:116)
com.xxxx.xxxx.framework.utils.PubUtilSignOnFilter.doFilter(PubUtilSignOnFilter.java:94)
com.xxxx.xxxx.framework.utils.PubUtilCharacterEncodingFilter.doFilter(PubUtilCharacterEncodingFilter.java:79)
root cause java.lang.NullPointerException问题描述： 频繁在一个菜单内选项和菜单之间切换就容易出现这个问题。出现出类似问题的请告诉下。讨论也可以呀