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Re: Object Creation in ozone

Hi Falko,

Thanks very much for your prompt reply. Your support is very much 
appreciated.

The sample code is below. I don't fully understand the implications of your 
statement 'Setting a static member of Repository that holds the client's 
database object will not work because...'.

Once a database is opened what are the proper ways to get or pass a 
reference to it for objects from the client and server sides?

Thanks again,

don

-----------------------------------

import java.util.*;
import org.ozoneDB.*;


public class Repository extends Object {

    public static void open ()throws Exception {

        db = new LocalDatabase();
        try {
            db.open ("/tmp/db");
            }
        catch (Exception e) {
            System.out.println ("No DB found, creating...");
            db.create ("/tmp/db");
            db.open ("/tmp/db");
            }

        db.reloadClasses();
        System.out.println ("connected...");

      }

	public static void close() throws Exception {
	  db.close();
	  System.out.println ("deconnected...");
	}

	public static LocalDatabase getDB() {return db;}

	private static LocalDatabase db;

    }

------------------------


import java.util.*;
import org.ozoneDB.*;


public class Local extends Object {

    public static void main (String [] args)throws Exception {

     Repository.open();

     LocalDatabase db = Repository.getDB();

     System.out.println(db.createObject (ObjectOneImpl.class.getName(), 0, 
null));

     Repository.close();

  }
}

----------------------------

import org.ozoneDB.*;
import java.util.*;


public class ObjectOneImpl extends OzoneObject implements ObjectOne {

   public ObjectOneImpl(){
     System.out.println("creating ObjectOne");
     try {
        Repository.getDB().createObject (ObjectTwoImpl.class.getName(),0, 
null);
     } catch (Exception e) {
        System.out.println(e);
     }
   }

   public void setName (String aName){name = aName ;}
   public String getName(){return name;}
   private String name;


}

-----------------

import org.ozoneDB.*;
import java.util.*;


public interface ObjectOne extends OzoneRemote  {

   public void setName (String name) ; /*update*/

   public String getName();
}

--------------------

import org.ozoneDB.*;
import java.util.*;


public interface ObjectTwo extends OzoneRemote  {

   public void setName (String name) ; /*update*/

   public String getName();
}

---------------------

import org.ozoneDB.*;
import java.util.*;


public class ObjectTwoImpl extends OzoneObject implements ObjectTwo {

   public ObjectTwoImpl () {System.out.println("Creating ObjectTwo");}

   public void setName (String aName){name = aName;}
   public String getName(){return name;} ;
   private String name;


}

----------------------------


>From: Falko Braeutigam <falko@smb-tec.com>
>To: "Don Berendsen" <donberendsen@hotmail.com>, ozone-users@ozone-db.org
>Subject: Re: Object Creation in ozone
>Date: Fri, 11 Aug 2000 12:22:52 +0200
>
>On Fri, 11 Aug 2000, Don Berendsen wrote:
> > In my application objects often initialize their state by creating other
> > objects in their constructor.
> >
> > However when creating an OzoneObject ObjectOne whose constructor (see
> > example below) initiates the creation an OzoneObject ObjectTwo, calling
> > createObject(ObjectOneImpl....) returns an ObjectTwoImpl_Proxy instead 
>of an
> > ObjectOneImpl_Proxy.
> >
> > Is there a way to get the correct createObject() return value while 
>doing
> > nested object creation such as this?
> >
> > cheers,
> >
> > don
> >
> >
> > example ObjectOne constructor:
> >
> > public ObjectOneImpl(){
> >       try {
> >         obj2 = (ObjectTwo) Repository.getDatabase().createObject
> > (ObjectTwoImpl.class.getName(),0, null);
> >       } catch (Exception e) {
> >         System.out.println(e);
> >       }
> >     }
>
>Hmmm... where does the static getDatabase() of Repository get the database
>object from? The implementation of such a method has to check if the class
>lives in the server or the client. (there is no documented way to do so)
>Setting a static member of Repository that holds the client's database 
>object
>will not work because the ctor of the database object is called on the 
>server
>side. Don, can you send the code of Repository.getDatabase()?
>
>
>Falko
>--
>______________________________________________________________________
>Falko Braeutigam                              mailto:falko@smb-tec.com
>SMB GmbH                                        http://www.smb-tec.com
>

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