Thanks Robin,
Any chance you could show us a little bit concerning your plan for the DAO
work that you are doing? It might be good to get the feedback at the
design phase of your work
Regards,
Mark
On Thu, Apr 5, 2012 at 7:18 AM, Robin Taylor <robin.tay...@ed.ac.uk> wrote:
> **
> Copying in the list on a discussion between Mark Diggory and myself since
> it may well be of interest to others.
>
> Mark - thanks, that's a great explanation.
>
> Cheers, Robin.
>
>
> On 05/04/12 14:41, Mark Diggory wrote:
>
> Ah... now we're talking.
>
> Can we bring this thread into the list, because this is the topic of how
> to implement your services correctly.
>
> 1.) For the database usecase, I don't see us wanting more than one DAO
> in place a time, correct. In this case we need to have the build/enduser
> choose which implemenetion should be in-force. I would recommend this is
> done by having separate spring config files for each and choosing between
> which is configured during the maven build, same as the manner in which we
> choose our database driver via the maven build.
>
> In the async release approach, these would have been completely separate
> maven projects, choosing the to build and include the dependency for the
> oracle one when -Ddb.name=*oracle*
> *
> *
> 2.) For the dspace.cfg plugins, multiple named implementations requires us
> to use "autowiring" to complete. In this case we have two approaches to
> choose from. Take a look over this example for identifier services.
>
>
> http://code.google.com/p/dryad/source/browse/trunk/dryad/dspace/modules/identifier-services/src/main/resources/spring/spring-dspace-core-services.xml?r=4766
>
>
> http://code.google.com/p/dryad/source/browse/trunk/dryad/dspace/modules/api/src/main/resources/spring/spring-dspace-core-services.xml?r=4766
>
> if these were combined into one we would have something like...
>
> <beans xmlns="http://www.springframework.org/schema/beans";
>
>
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
>
>
> xmlns:context="http://www.springframework.org/schema/context";
>
>
> xsi:schemaLocation="http://www.springframework.org/schema/beans
>
>
>
> http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
> http://www.springframework.org/schema/context
>
>
>
> http://www.springframework.org/schema/context/spring-context-2.5.xsd";>
>
>
>
>
>
> <bean class="org.dspace.identifier.IdentifierServiceImpl" id=
> "org.dspace.identifier.IdentifierServiceImpl" autowire="byType"/>
>
>
> <bean class="org.dspace.identifier.HandleIdentifierService" autowire
> ="byType"/>
>
>
> <bean class="org.dspace.identifier.DOIIdentifierService" autowire=
> "byType"/>
>
>
>
>
> </beans>
>
> And you can see how efficient the coding of this can be in the
> IdentifierServiceImpl
>
>
> http://code.google.com/p/dryad/source/browse/trunk/dryad/dspace/modules/identifier-services/src/main/java/org/dspace/identifier/IdentifierServiceImpl.java?r=4766
>
> Here we've done two things.
>
> a.) We have a Bean property that is a list of IdentifierProviders
>
> public void setProviders(List<DSpaceIdentifierService> providers)
>
>
> b.) We've chosen to define one (HandleProvider) as default
>
> public void setHandleService(HandleIdentifierService handleService)
>
> Both these get autowired by spring and we write no code for
> such activities. You can use the autowire attribute in the xml file, or
> you can use annotations on the classes themselves to provide this wiring.
>
> Mark
>
> On Thu, Apr 5, 2012 at 1:31 AM, Robin Taylor <robin.tay...@ed.ac.uk>wrote:
>
>> Hi Mark,
>>
>> Sorry, I answered in a hurry last night without thinking properly. I
>> still have a wee problem. If I use the interface as the bean id then
>> presumably I can only have one class associated with that id/interface in
>> the spring config. That causes a problem for me as I will want to have
>> multiple classes implementing the same interface ie...
>>
>> PostgresCollectionDAO, OracleCollectionDAO, etc all implementing
>> CollectionDAO
>>
>> In fact I think the same problem would arise for many of the plugins
>> listed in dspace.cfg ?
>>
>> Cheers, Robin.
>>
>>
>>
>> On 04/04/12 17:50, Mark Diggory wrote:
>>
>> Robin, its interface centric. you will want to create an interface for
>> your DAO class, it is this interface that is cast to and utilized by the
>> code using your api.
>>
>> CollectionDAO collectionDAO = new
>> DSpace().getSingletonService(CollectionDAO.class);
>>
>> <bean id="org.dspace.content.dao.CollectionDAO"
>> class="org.dspace.content.dao.PostgresCollectionDAO" />
>>
>>
>> On Wed, Apr 4, 2012 at 2:21 AM, Robin Taylor <robin.tay...@ed.ac.uk>wrote:
>>
>>> Hi Mark,
>>>
>>> Can I ask a daft Spring question ? Looking at org.dspace.utils.DSpace I
>>> was surprised to find no method that would be the equivalent of the Spring
>>> ApplicationContext getBean(String) method. I had to code...
>>>
>>> CollectionDAO collectionDAO = new
>>> DSpace().getSingletonService(PostgresCollectionDAO.class);
>>>
>>> with a Spring config of...
>>>
>>> <bean id="org.dspace.content.dao.PostgresCollectionDAO"
>>> class="org.dspace.content.dao.PostgresCollectionDAO" />
>>>
>>> Which effectively hardwires a particular implementation of CollectionDAO
>>> into the code. Was this a deliberate design choice or did it just fulfil
>>> the needs at the time of the DSpace 2.0 work ?
>>>
>>> I am a bit of a Spring/Services novice so apologies if this is a daft
>>> question.
>>>
>>> Cheers, Robin.
>>>
>>>
>>>
>>> --
>>> The University of Edinburgh is a charitable body, registered in
>>> Scotland, with registration number SC005336.
>>>
>>>
>>
>>
>> --
>> [image: @mire Inc.]
>> *Mark Diggory *(Schedule a
>> Meeting<https://www.google.com/calendar/selfsched?sstoken=UUdDSzJzTTlOUE1mfGRlZmF1bHR8MzgwMmEwYjk1NDc1NDQ1MGI0NWViYjYzZjExZDI3Mzg>
>> )
>> *2888 Loker Avenue East, Suite 305, Carlsbad, CA. 92010*
>> *Esperantolaan 4, Heverlee 3001, Belgium*
>> http://www.atmire.com
>>
>>
>>
>>
>> The University of Edinburgh is a charitable body, registered in
>> Scotland, with registration number SC005336.
>>
>>
>
>
> --
> [image: @mire Inc.]
> *Mark Diggory *(Schedule a
> Meeting<https://www.google.com/calendar/selfsched?sstoken=UUdDSzJzTTlOUE1mfGRlZmF1bHR8MzgwMmEwYjk1NDc1NDQ1MGI0NWViYjYzZjExZDI3Mzg>
> )
> *2888 Loker Avenue East, Suite 305, Carlsbad, CA. 92010*
> *Esperantolaan 4, Heverlee 3001, Belgium*
> http://www.atmire.com
>
>
>
>
> The University of Edinburgh is a charitable body, registered in
> Scotland, with registration number SC005336.
>
>
--
[image: @mire Inc.]
*Mark Diggory *(Schedule a
Meeting<https://www.google.com/calendar/selfsched?sstoken=UUdDSzJzTTlOUE1mfGRlZmF1bHR8MzgwMmEwYjk1NDc1NDQ1MGI0NWViYjYzZjExZDI3Mzg>
)
*2888 Loker Avenue East, Suite 305, Carlsbad, CA. 92010*
*Esperantolaan 4, Heverlee 3001, Belgium*
http://www.atmire.com
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