Groups > comp.lang.java.databases > #657

JPA: annotations or XML?

From	Ricardo Palomaes <rpmdisguise-java@nowhere.com>
Newsgroups	comp.lang.java.databases
Subject	JPA: annotations or XML?
Date	2013-12-16 21:48 +0100
Organization	Aioe.org NNTP Server
Message-ID	<l8nov9$sq4$1@speranza.aioe.org> (permalink)

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Hi,

I'm trying to use JPA for the first time in a small to mid Java SE
project (I expect it be around 50,000 lines, comments included).

I've always been against libraries using declarative XML files since I
felt that it added burden and an additional hurdle to use them besides
coding. As result of it, I initially liked very much annotations over
XML files in JPA.

However, I'd like to design the application in such a way that it
could use a local database persistence (now) or one based in
webservices (as a future enhancement). I'm still learning, but it
seems that I should use a DAO pattern. This is not a requirement, but
a "nice to have".

I have two questions:

1) (This may be really naive) I've read that JPA acts in some way as a
DAO layer but, will the JPA architecture keep track of entity object
passing through a "real" DAO layer, used in a context unaware of JPA
(the application GUI classes, for instance) and later returned again
to the JPA through the DAO without too much hassle?

2) Would I be able, by using XML files instead of annotations in JPA,
to keep my POJOs completely clean, so I could use them in both JPA and
webservice persistence providers in a DAO architecture, with the web
service part not having to include any package from JPA?

I know the answer to both questions may be "It depends on your code
and design" and "Start coding and later refactor", so I'm just looking
for general advice, not definitive answers.

TIA

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Thread

JPA: annotations or XML? Ricardo Palomaes <rpmdisguise-java@nowhere.com> - 2013-12-16 21:48 +0100
  Re: JPA: annotations or XML? Arne Vajhøj <arne@vajhoej.dk> - 2013-12-24 23:11 -0500
    Re: JPA: annotations or XML? Stanimir Stamenkov <s7an10@netscape.net> - 2013-12-25 13:21 +0200
      Re: JPA: annotations or XML? Arne Vajhøj <arne@vajhoej.dk> - 2013-12-27 22:34 -0500
        Re: JPA: annotations or XML? Stanimir Stamenkov <s7an10@netscape.net> - 2014-01-02 11:31 +0200

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