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EJB unidirectional CMR

 
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Hi,
How should I implement unidirectional relationship? Let's say I have this kind of relationship (btw from page 432):
Foo (0-1) -> Bar (0-1)
Do I have to have CMR fields in both Foo and Bar? If so then what does "unidirectional relationship" means in terms of implementation? Or maybe the only difference is I do not put Foo accessor methods into Bar class remote(or local) interface(s). In that case... does it makes any difference is it unidirectional or bidirectional to container?
My best regards
 
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Hi Vladas,
The <cmr-field> element is optional. To describe a unidirectional relationship, you simply define a <cmr-field> in *only one* of both <ejb-relationship-role> elements.
Best,
Phil.
 
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Hi, Vladas,
Let's look at relationship Customer-HomeAddress.
Customer must know his/her address, but Address does not need to know anything about it's customer.
Here is the piece of DD for this relationship:

It was taken from SCBCD Study Guide web-site.
As you can see, Address definition does not have cmr-field element. This means, Address have no idea about customer (the relation is unidirectional)
This and much-much more you can find there
Cheers!!!
 
Vladas Razas
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Thanks !
And likewise if I don't have CMR field it means I do NOT put abstract setter/getter for it
Nice site Mikalai! Now I see that bean with only remote interface may only have unidirectional relationship from one side.
My best regards
 
Mikalai Zaikin
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Now I see that bean with only remote interface may only have unidirectional relationship from one side.


yeah, you are absolutely right, bean with only Remote interface
can have [unidirectional] relationship to other bean (with local interface), but nobody can access it in CMR.

 
With a little knowledge, a cast iron skillet is non-stick and lasts a lifetime.
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