problem on web app using root context (/) in weblogic 7.0.2

[Wallace Fu]

I got problem on servlet which running on root context "/" in weblogic 7.0.2. I have remove the default web app (which use the root context) before the web app. The web application was deployed without any error. However, when the servlet run to the line calling HttpSession.setAttribute, the following exception occurs. The weblogic server is running on Solaris 8. anyone can help?

java.lang.IllegalStateException: Internal Servlet Session Process Error Found!
at weblogic.servlet.internal.session.SessionData.checkProcess(SessionData.java:1045)
at weblogic.servlet.internal.session.SessionData.setAttribute(SessionData.java:477)
at com.chase.infra.appcontrol.servlet.LoginServlet.doPostHK(Unknown Source)
at com.chase.infra.appcontrol.servlet.LoginServlet.doPost(Unknown Source)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
at weblogic.servlet.internal.ServletStubImpl$ServletInvocationAction.run(ServletStubImpl.java:1058)
at weblogic.servlet.internal.ServletStubImpl.invokeServlet(ServletStubImpl.java:401)
at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:20)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:27)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:5451)
at weblogic.security.service.SecurityServiceManager.runAs(SecurityServiceManager.java:780)
at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3105)
at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2588)
at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:213)
at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:189)

The weblogic.xml is

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE weblogic-web-app
PUBLIC "-//BEA Systems, Inc.//DTD Web Application 7.0//EN"
"http://www.bea.com/servers/wls700/dtd/weblogic700-web-jar.dtd" >
<weblogic-web-app>

<context-root>/</context-root>


</weblogic-web-app>