Re: [eclipselink-users] Code generation tool for persitence layer (from

["Tim Hollosy" <hollosyt@xxxxxxxxx>]

Well, already by using an ORM like EclipseLink you don't have to write
SQL to do deletes/updates/inserts right?

So what code are you trying to generate for DAO's? a call to
entityManager.merge?

Your DAO is independent of any specific entities, so you don't need to
make 30 different implementations of it.

Here's an example of a SimpleDAO that I use on it's own or extend if I
need a special one.

(Ignore Spring annotations, and you may have to change you you obtain
your entity manager if you're not using spring dependency
injection...)



import java.util.List;

import javax.annotation.PostConstruct;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceContext;
import javax.persistence.PersistenceUnit;
import javax.persistence.Query;

import org.eclipse.persistence.jpa.JpaEntityManager;
import org.eclipse.persistence.jpa.JpaHelper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.orm.jpa.JpaCallback;
import org.springframework.orm.jpa.support.JpaDaoSupport;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

@Transactional
@Repository
public class SimpleDao {
	
	@PersistenceContext
	private EntityManager entityManager;


	public EntityManager getEntityManager()
	{
		return entityManager;
	}
	
	@Transactional(propagation=Propagation.REQUIRED)
	public void insert(Object entity)
	{
		entityManager.persist(entity);
	}
	
	@Transactional(propagation=Propagation.REQUIRED)
	public <T> T save(T entity)
	{
		return entityManager.merge(entity);
	}
	
	@Transactional(propagation=Propagation.REQUIRED)
	public void delete(Object entity)
	{
		entityManager.remove(entity);
	}
	
	@Transactional(readOnly = true)
	public <T> T find(Class<T> entityClass, Object primaryKey) {
		return entityManager.find(entityClass, primaryKey);
	}


	@Transactional(readOnly = true)
	public <T> List<T> selectAll(Class<T> clazz) {
		return (List<T>)
JpaHelper.getEntityManager(entityManager).createQuery(null,
clazz).getResultList();
		
		JpaHelper.getEntityManager(entityManager).createQuery(null, clazz).set
	}
	


}



./tch



On Mon, Nov 24, 2008 at 9:18 AM, Chiovari Cristian Sergiu
<csergiu77@xxxxxxxxx> wrote:
> Sorry for asking you again:
>
> What do you mean by :"Code
>> gen seems like the wrong solution for DAO's.
>> "?
>
> Thx again
>
>
> --- On Mon, 11/24/08, Tim Hollosy <hollosyt@xxxxxxxxx> wrote:
>
>> From: Tim Hollosy <hollosyt@xxxxxxxxx>
>> Subject: Re: [eclipselink-users] Code generation tool for persitence layer (from database)
>> To: "EclipseLink User Discussions" <eclipselink-users@xxxxxxxxxxx>
>> Date: Monday, November 24, 2008, 4:15 PM
>> Why don't you just write your DAO once and extend it
>> when needed? Code
>> gen seems like the wrong solution for DAO's.
>>
>> ./tch
>>
>>
>>
>> On Mon, Nov 24, 2008 at 9:04 AM, csergiu77
>> <csergiu77@xxxxxxxxx> wrote:
>> >
>> >
>> > Thx.
>> >
>> > That is what i want to avoid :) (i'm lazy in write
>> code that repeats in
>> > logic and structure)
>> >
>> > There is something on the market called Firestorm DAO
>> but I wondered if
>> > there is no other magic toold that code all simple
>> persitance layer from
>> > database (only simple insert,update,delete,findAll) ?
>> >
>> >
>> >
>> >
>> >
>> > Tim Hollosy wrote:
>> >>
>> >> Well for JPA in Eclipse there is Dali (JPA Tools).
>> >>
>> >> After that you don't have to write code to
>> make inserts/updates/deletes :)
>> >>
>> >> Though, many people have a common "DAO"
>> class for selectAll, etc. That
>> >> really depends on the framework you're using
>> though -- how you make
>> >> your DAO class.
>> >>
>> >> ./tch
>> >>
>> >>
>> >>
>> >> On Sat, Nov 22, 2008 at 1:06 PM, csergiu77
>> <csergiu77@xxxxxxxxx> wrote:
>> >>>
>> >>>
>> >>> Do you know any good persistence layer code
>> generation tool ? (not only
>> >>> for
>> >>> JPA)
>> >>>
>> >>> To generate simple
>> inserts,update,delete,getAll...,findBy bla bla stuff
>> >>> and
>> >>> create the interfaces and necessary factories.
>> >>>
>> >>> THX !
>> >>>
>> >>>
>> >>>
>> >>> --
>> >>> View this message in context:
>> >>>
>> http://www.nabble.com/Code-generation-tool-for-persitence-layer-%28from-database%29-tp20639046p20639046.html
>> >>> Sent from the EclipseLink - Users mailing list
>> archive at Nabble.com.
>> >>>
>> >>>
>> _______________________________________________
>> >>> eclipselink-users mailing list
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>> >>>
>> https://dev.eclipse.org/mailman/listinfo/eclipselink-users
>> >>>
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>> >> eclipselink-users mailing list
>> >> eclipselink-users@xxxxxxxxxxx
>> >>
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>> >>
>> >>
>> >
>> > --
>> > View this message in context:
>> http://www.nabble.com/Code-generation-tool-for-persitence-layer-%28from-database%29-tp20639046p20661083.html
>> > Sent from the EclipseLink - Users mailing list archive
>> at Nabble.com.
>> >
>> > _______________________________________________
>> > eclipselink-users mailing list
>> > eclipselink-users@xxxxxxxxxxx
>> >
>> https://dev.eclipse.org/mailman/listinfo/eclipselink-users
>> >
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