Re: DataContext x EJB

From: Andrus Adamchik (andru..bjectstyle.org)
Date: Thu Apr 15 2004 - 14:31:19 EDT

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    On Apr 15, 2004, at 8:46 AM, Leonardo Queiroz Antunes wrote:

    > Hi everybody!
    >
    > Which is the best way to retrieve the DataContext inside a Session
    > Bean.
    >
    > Thank´s
    > Leonardo Antunes

    Hi,

    Per our rather primitive EJB example
    (http://objectstyle.org/cayenne/examples/ejb-facade/index.html), the
    context is created right inside the business method as "DataContext
    cayenneContext = DataContext.createDataContext();"

    However this might not be a good idea, if you chain a few EJB calls in
    the same transaction, and want the same set of data objects shared by
    all of them. What you can do instead is implement a simple static
    method in one of your utility Java classes, wrapping a DataContext in a
    ThreadLocal:
    http://java.sun.com/j2se/1.4.2/docs/api/java/lang/ThreadLocal.html, and
    later use this static method to get the context within a bean.

    I will probably add such "thread-local" DataContext method to Cayenne
    at some point, for now you'll have to write this yourself.

    Andrus

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