Re: Strange servlet exception

From:

Daniel Pitts <googlegroupie@coloraura.com>

Newsgroups:

comp.lang.java.programmer

Date:

Fri, 1 Feb 2008 12:10:41 -0800 (PST)

Message-ID:

<1aaa7ed2-073b-4474-be3f-a06f21c9adbb@e6g2000prf.googlegroups.com>

On Feb 1, 7:35 am, CarloC <ccamu...@gmail.com> wrote:

Hi,
inside my generic servlet I get this error when I call this method:
'session.getAttribute' command (line 36):

java.lang.NullPointerException
        at java.util.Hashtable.get(Hashtable.java:336)
        at
org.apache.catalina.session.StandardSession.getAttribute(StandardSession.java:
1024)
        at
org.apache.catalina.session.StandardSessionFacade.getAttribute(StandardSessionFacade.java:
110)
        at workcity.servlet.GenericServlet.checkToken(GenericServlet.java:36)

This is the java code:

HttpSession session = req.getSession();
ArcUtente vo = (ArcUtente) session.getAttribute(token);

req is a HttpServletRequest object !=null and
token is a String object != null.

You can help my?
Carlo

Looking at the JavaDoc for Hastable:
* @throws NullPointerException if the specified key is null
It very well could be token really is null.
Just to verify, try this:

HttpSession session = req.getSession();
if (token == null) { throw new NullPointerException("Token really IS
null!") };
ArcUtente vo = (ArcUtente) session.getAttribute(token);

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