Re: transactions

Hello all,

My purpose of giving the previous example by writing transactions was
so that I create some database objects , store the objects(persistent),
close the database and when I open the database again , I am able to 
retrieve
the object.

Now this works fine with the Bus and Auto example, there in the samples
directory. I modified the code of the Client.java to check that.

But when I try to do the same with my defined classes, I get a stack 
overflow.
I can try to give a feel of what my class definitions look like and what I 
am trying
to do.

public interface A extends OzoneRemote{
// getter setter methods
// additional methods
}

public abstract class AImpl extends OzoneObject implements A{
//member variables - HashSet, HashMap , Strings ..

// methods
}


public interface B extends A{
// getter setter methods
// additional methods
}

public class BImpl extends AImpl implements B{
//member variables - HashSet, HashMap , Strings ..

// methods
}

Now I am trying to store objects of class B , when I get this problem.
These are the operations I am trying to do now..

String dbDir = "D:/test/database";
LocalDatabase db = new LocalDatabase();
if(!db.exists(dbDir))
   db.create(dbDir);			

db.open(dbDir);
B b = (B)db.createObject(BImpl.class.getName(),0,"bnode");
b.setName("B node check");

db.close();
// opening database after closing
// check for the "bnode"
db.open(dbDir);
b = (B)db.objectForName("bnode");
System.out.println("B instance name "+b.getName());		
db.close();	

And when I do this , I get this
      [java] WARN   [main] Transaction - ta[id=5102,blocker=null]: uncaught 
exception: (java.lang.StackOverflowError)
      [java] java.lang.StackOverflowError
      [java] WARN   [main] Transaction - ta[id=5102,blocker=null]: uncaught 
exception: (java.lang.StackOverflowError)
      [java] java.lang.StackOverflowError
      [java] java.lang.StackOverflowError
      [java]     at 
org.ozoneDB.ExternalDatabase.sendCommand(ExternalDatabase.java:536)
      [java]     at 
org.ozoneDB.ExternalDatabase.sendCommand(ExternalDatabase.java:490)
      [java]     at 
org.ozoneDB.ExternalDatabase.objectForName(ExternalDatabase.java:760)

 From the stack trace, the error is for a call on
b = (B)db.objectForName("bnode");


Any tips for where the error lies will be helpful.

Thank You

Regards
Sunil



On 02 Mar 2004 16:57:49 +0100, Leo Mekenkamp <[email protected]> 
wrote:

> While I think using external transactions is overkill in this situation
> (and use of external transactions should be avoided if not explicitly
> needed, implicit transactions are better and produce better readable
> code), I cannot see any reason why this would go wrong.
>
> Maybe one of the other people on this list?
>
> Cheers,
> Leo

-- 
=====================================================================
Sunil Goyal
New Media Lab
Salzburg Research Forschungsgesellschft m.b.H.
Jakob Haringer-Strasse 5/III | A-5020 Salzburg
T: +43.662.2288-414 | F: +43.662.2288-222
[email protected]
http://www.salzburgresearch.at
======================================================================


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