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| | | Association vs Dependency (Offbeat) | Association vs Dependency (Offbeat) 2003-12-30 - By ashraf galal
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<html><div style='background-color:'><P>Hi ShriKant;</P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="COLOR: black"><FONT
size=3><FONT face="Times New Roman">When you have an abstract class and its
concret implementation class, it is some sort of dependency.<?xml
:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o
:p></FONT></FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="COLOR: black"><FONT
size=3><FONT face="Times New Roman"> <o:p></o:p></FONT></FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0in 0in 0pt"><SPAN style="COLOR: black"><FONT
size=3><FONT face="Times New Roman">I am not meant template deign pattern
neither C++ templates, I mean <SPAN style="mso-spacerun: yes"> </SPAN
>parameterized class, even the concept applies to any design pattern in J2EE or
any other languages.<o:p></o:p></FONT></FONT></SPAN></P>
<P><BR><BR> </P><BR><BR><BR>
<DIV>Ashraf Galal <BR>(416)804-8359</DIV>>From: ShriKant Vashishtha
<SHRIKANT.VASHISHTHA@(protected)>>Reply-To: An interest list for Sun Java
Center J2EE Pattern Catalog <J2EEPATTERNS-INTEREST@(protected)>>To:
J2EEPATTERNS-INTEREST@(protected) >Subject: Re: Association vs Dependency
(Offbeat) >Date: Tue, 30 Dec 2003 14:05:42 -0600 > >Hi Ashraf, > >
;I am sorry if I understood you correctly. >What do you mean by abstraction
in this context and its relation with >dependency. When you talk about
template, are you talking about template >method design pattern or C++
templates? > >Please clarify. > >Thanks >-ShriKant > > >
; > >ashraf galal <ASHRAFWG@(protected)>>Sent by: An interest list for
Sun Java Center J2EE Pattern Catalog ><J2EEPATTERNS-INTEREST@(protected)>
>12/30/2003 01:46 PM >Please respond to An interest list for Sun Java
Center J2EE Pattern >Catalog > > > To: J2EEPATTERNS-INTERE
ST@(protected) > cc: > Subject: Re: Association vs Dependency (Offbeat)
> > >ShriKant; >Dependency relates the model elements themselves
and does not require a >set of instances for its meaning."urn:schemas
-microsoft-com:office:office" /> > >Dependency indicates a situation in
which a change to the supplier may >require a change to or indicate a change
in meaning of the client in the >dependency. > > >1- has a
reference to an object directly. >InstanceOf and abstraction are example of
this type. >2- has a reference to an object indirectly via some operation
>parameters: >A template class is an example of this type. >You can not
use a template directly, you have to instantiate it first. >Instantiation
involves binding these formal template parameters to actual >ones. >The
result is a concrete class hat can be used as any ordinary one. > Dependency
between packages is another example. > > >Also I
would like to keep your attention that association and >generalization fit
within the general definition of dependency, but they >have their own model
representation and notation and are not usually >considered to be dependency
(UML). > >So we need to make explicit relationship between UML and J2EE.
> > > > > >Ashraf Galal >(416)804-8359 > >From:
ShriKant Vashishtha >Reply-To: An interest list for Sun Java Center >J2EE
Pattern Catalog >To: J2EEPATTERNS-INTEREST@(protected) >Subject: Re: >
;Association vs Dependency (Offbeat) >Date: Tue, 30 Dec 2003 09:01:54 -0600
> > >Hi Ashraf, > >I am quite clear regarding unidirectional and
>bidirectional association. >But could you please elaborate the following
>points more, may be with some >examples. > >- has a reference to an
object >directly. >- Has a reference to an object indirectly via some
operation > >parameters. > >Th
anks >-ShriKant > > > > >ashraf galal >Sent by: An >
;interest list for Sun Java Center J2EE Pattern Catalog > >12/29/2003 11
:22 >PM >Please respond to An interest list for Sun Java Center J2EE
Pattern > >Catalog > ; > > To: J2EEPATTERNS-INTEREST@(protected)
.COM > cc: > Subject: >Re: Association vs Dependency (Offbeat) > >
; >Actually, these concepts is >UML not a java. You are quite well >
;understanding but I would like to >illustrate the difference between them
>and give an example. > /> > >Dependency : >Anytime a class
uses another class in some fashion, a >dependency exists >between the two
. >A dependency exists of a class: >- >has a reference to an object
directly. >- Has a local variable based on >another class. >- Has a
reference to an object indirectly via some >operation >parameters. >-
Uses a class's static operation >Also there are >depend
ency between packages. > >Association: >There is two types of >
;association, unidirectional and bi-directional >associations. > >
;Unidirectional association implies that an object of the class may invoke >
>methods on the other class. >In java, this manifest itself as an instance
>variables on the class that >may invoke methods. > >Example: >
;Public class >customer > { > ?. > Public Address homeAddress; >
> ?? > } > >public class >Address { >?.. >} > >bi
-directional association means that either object >in the association may >
;invoke methods on other. >In java, this results in >an instance variable
on each class based on the >type of the other class. > > >Example;
>Public class Team > { > LinkedList teamPlayers = new >LikedList();
> teamPlayers.add(new teamPlayer(?)); > ??? } > > public >class
teamPlayer { > Team memberOf; > ?. > } &
gt; >Ashraf Galal > >(416)804-8359 > >From: ShriKant Vashishtha
>Reply-To: An interest list >for Sun Java Center >J2EE Pattern Catalog
>To: >J2EEPATTERNS-INTEREST@(protected) >Subject: >Association vs
Dependency >(Offbeat) >Date: Sun, 28 Dec 2003 14:17:03 -0800 > >
>Hi All, > >I am >slightly confused in finding the difference
between >association and >dependency. > >For me, whenever the
variable is intialized >at a local >scope or passed as a parameter in a
method, its denoted as >dependency. >However, for association, I believe,
the object needs to be on >global >scope (as an instance variable).
However, I rarely use any object >at a >global scope, unless I know that
it is used for maintaining the state >of >class or need to be used across
different methods. So most of the time, >I >end up with dependency . >
>Am I missing something over here. > >Thanks &
gt; > >-ShriKant > > >-- ---- --- -- ---- ---- ---- ---- >Do
you Yahoo!? > > >Protect your identity with Yahoo! Mail AddressGuard
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