Re: nullpointerexception from ctxt.performQuery

From: Andrus Adamchik (andru..bjectstyle.org)
Date: Tue Feb 04 2003 - 16:05:46 EST

  • Next message: Holger Hoffstätte: "Re: nullpointerexception from ctxt.performQuery"

    > Yes, this is how the Datacontext is created:
    >
    > DataContext ctxt = (DataContext)
    > request.getSession().getAttribute("context");
    >
    > //this is where we choke.
    > SelectQuery query = new SelectQuery(Artist.class);
    >

    This line shouldn't cause the NPE, the one with "performQuery" maybe?

    Anyway, I think I know what it is. And it is indeed a bug in the tutorial
    (I need to doublecheck this some more when I get home).

    You preserved these lines in your web.xml, right?
    <listener>
          <listener-class>webtest.CustomConfiguration</listener-class>
    </listener>

    If so, DataContext is created by CustomConfiguration's superclass when the
    session is staryed. But the key to retrieve it is defined under
    ServletConfiguration.DATA_CONTEXT_KEY as "cayenne.datacontext". Try using
    this key instead. Or use CustomConfiguration.getDefaultContext().

    Let me know if this works. In the meantime I will see if tutorial code
    needs to be fixed.

    Andrus



    This archive was generated by hypermail 2.0.0 : Tue Feb 04 2003 - 16:05:46 EST