Re: [Simple-support] How to deserialize from a stream

[Tony T. <Ton...@st...>]

So, if I create the Strategy to write, how do I read the objects back,
persister.read( ????, input )?  If the class= attribute is in the XML,
does the read() method ignore the type parameter?  I am still confused
about that part, sorry.

Thanks for the detailed response.
Tony

-----Original Message-----
From: Niall Gallagher [mailto:gal...@ya...] 
Sent: Thursday, September 04, 2008 3:31 AM
To: sim...@li...; Tony Thompson
Subject: Re: [Simple-support] How to deserialize from a stream

Hi,

Yes you can, with a strategy. Currently I do not support top level
class="some.class.Name" attributes. The reason is because class=
attributes are only written when the expected type is a subclass of the
type. I should really add a method such as.

Persister.write(Object value, Class expect, OutputStream out);

Then you could write.

persister.write(value, Object.class, out);

Resulting in a class= attribute at the top leven. However, you can still
do this if you like. Create a strategy like so.

public class MyStrategy implements Strategy {

private final Strategy strategy;

public MyStrategy(Strategy strategy){
  this.strategy  = strategy;
}   	

public boolean setRoot(Class field, Object value, NodeMap node, Map
map){
  return strategy.setRoot(Object.class, value, node, map);    
}   
}

And create it like so:

Strategy main = new DefaultStrategy();
Strategy mine = new MyStrategy(main);
Persister persister = new Persister(mine);

Then you will see top leven class= attributes. Note though you will have
to make org.simpleframework.xml.load.DefaultStrategy public. It is
currently package protected. I will make it public in the next release
as it really is needed to do most non-standard things with simple. Hope
this works, if it does not let me know.

A good starting point for learning what the Strategy is, is the javadoc,
tutorial, and the unit tests which come with the download.

Regards,
Niall

 

--- On Wed, 9/3/08, Tony Thompson <Ton...@st...> wrote:

> From: Tony Thompson <Ton...@st...>
> Subject: [Simple-support] How to deserialize from a stream
> To: sim...@li...
> Date: Wednesday, September 3, 2008, 10:35 AM I was able to serialize 
> several objects to an output stream but now I would like to stream 
> them back.  There are too many objects to load them all into memory at

> once.  It looks the Persister.read() method will work but, I have to 
> pass in the object type that I am reading.
> I don't know
> what the type of the next object is because I have several different 
> object types written to the XML file.  Is there a way to stream each 
> object back (one object in memory at a time) without knowing the 
> object type ahead of time?
>  
> I was able to serialize/deserialize all of my objects when I put them 
> in a wrapper object and used @ElementList but, that requires they are 
> all in memory at the same time so it really doesn't help me.  Any 
> other input would be helpful.
>  
> Thanks.
> Tony
>  
> This message (and any associated files) is intended only for the use 
> of the individual or entity to which it is addressed and may contain 
> information that is confidential, subject to copyright or constitutes 
> a trade secret. If you are not the intended recipient you are hereby 
> notified that any dissemination, copying or distribution of this 
> message, or files associated with this message, is strictly 
> prohibited. If you have received this message in error, please notify 
> us immediately by replying to the message and deleting it from your 
> computer. Messages sent to and from Stoneware, Inc.
> may be monitored.
> ----------------------------------------------------------------------
> --- This SF.Net email is sponsored by the Moblin Your Move Developer's

> challenge Build the coolest Linux based applications with Moblin SDK &

> win great prizes Grand prize is a trip for two to an Open Source event

> anywhere in the world 
> http://moblin-contest.org/redirect.php?banner_id=100&url=/____________
> ___________________________________
> Simple-support mailing list
> Sim...@li...
> https://lists.sourceforge.net/lists/listinfo/simple-support