does this work for me? Any problem could you see?
i will load members companies of specified company from database and save it in memory.
my DAO will be like this.
///////////////////////////////////////////////
class CompanyDAO{
    HashMap loadedCompanies;

    get(String id){}    
    del(String id){}
    delMemory(String id){
          return loadedCompanies.remove(id);
    }
    getMemory(String id){
          return loadedCompanies.get(id);
    }
    ...
}
////////////////////////////////////////////////
So that i can have only one instance for all objects.






-----Original Message-----
From: An interest list for Sun Java Center J2EE Pattern Catalog [mailto:J2EEPATTERNS-INTEREST@(protected)
Sent: Wednesday, January 05, 2005 4:23 PM
To: J2EEPATTERNS-INTEREST@(protected)
Subject: Re: Object relationship


Depending on your usage, you may also want to consider a
TransferObjectAssembler to differentiate between cases when you need the
company with sub-companies or without. Then apply the Mutiple Transfer
Object strategy so you have slightly different TransferObjects (ValueObjects)
for the two cases. One could be a subclass of the other to make things a bit
more transparent.

--
Jonathan Petruk
J. Petruk Consulting Inc.
E-mail: jon@(protected)
http://www.petruk.net/


On Wed, 5 Jan 2005 14:13:43 -0000, Ramnish Kalsi wrote
> This would actually depend upon the usage. If the company object is not
> complete without members information, then yes, you would have to
> load the member information.
>
> Alternately, if you do not need the information about the members,
> you could either maintain a list of ID's of the organization
> (instead of whole objects) , that this company is member of.
>
> But, firstly, you should redefine your business model slightly -
> when you say "a company is member of other companies", what exactly
> do you mean. Is it an amalgamation of companies ?? If so, will the
> company object be accurate depiction of this umbrella business
> entity. ?
>
> think about these before you finalise your model.
>
> --ramnish.
>
> -----Original Message-----
> From: An interest list for Sun Java Center J2EE Pattern Catalog
> [mailto:J2EEPATTERNS-INTEREST@(protected)
> VOLODYA (YAZ-ArGe)
> Sent: 05 January 2005 14:03
> To: J2EEPATTERNS-INTEREST@(protected)
> Subject: Object relationship
>
> Hi all,
>
> a company can be member of other companies.
> class company{
>  ArrayList membersOf;
> }
>
> when i load this company from database, do i have to load member companies
> too?
> if yes, i must load members of the members'. huh?
> if no, nullpointer issue !!!
>
> how do i handle that?
>
> thanks.
> Bayarsaikhan VOLODYA
>
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