RE: [picocontainer-dev] Constructor Injection and Serialization Patterns

Sorry for not getting it, but I don't think I understand how Objenesis would
help with this problem?

 

What I want is to be able to:

 

ObjectInputStream ois = new ObjectInputStream( /* some input stream */ );

Sample s = (Sample)ois.readObject();

 

/* And then a miracle occurs! */

 

assert s.getClassLoader() != null;

 

And somehow have Sample useful, even if the classloader specified in the
constructor would have to be transient. (Or just not saved via custom
serialization/externalization).  

 

So far, the only things I can think of are atatic containers and have class
Sample read its own dependencies during readObject(). which of course, breaks
everything in the Pico book in only one function. :-)

 

Does this clarify my problem?  I suspect this isn't really anything Pico can
solve per-se, rather a standard pattern for dealing with this problem would be a
good thing to document.

 
-Mike

 

 

From: Paul Hammant [mailto:[email protected]] 
Sent: Tuesday, February 26, 2008 9:35 AM
To: dev-qxt/[email protected]
Subject: Re: [picocontainer-dev] Constructor Injection and Serialization
Patterns

 

It could be that we leverage http://code.google.com/p/objenesis/ for a variation
of ConstructorInjection.

 

We would bring it in to the PicoContainer jar as per Paranamer with 'shade'

 

That way you can have your cake and eat it ? Or am I missing the problem here ?

 

- Paul

 

On Feb 26, 2008, at 8:42 AM, Michael Rimov wrote:





Hi All,

 

Pico was my first initiation into constructor injection and I've been an avid
fan after finding it.  However, I'm lacking a solution to a problem that I keep
encountering.

 

Given the sample class:

 

public class Sample implements Serializable {

      private ClassLoader cl;

 

      public Sample(ClassLoader classLoader) {

            cl = classLoader;

      }

}

 

The problem that I have is that since ClassLoader is not serializable, neither
is Sample.  If I make the classloader transient, then I deserialize a useless
object.

 

So far, the only solution I can see is to downgrade to setter injection.
(yuck!).

 

Has anybody come up with some sort of externalization pattern that they use in
practice that I can add to the "Best Practices" section for the Pico Docs?
Anything, especially in mind of usage in XStream, would be great :D

 

Thanks in advance!

                                                            -Mike