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Posted to user@geronimo.apache.org by zeros <se...@gmail.com> on 2008/05/28 01:09:25 UTC
JPA, entities and EJB3
Good evening:
I'm newbie with EJB3.0. I want to configure the persistence.xml to have
entities managed with JPA. I have the next configuration files:
OPENJPA-JAR.XML
<openejb-jar xmlns="http://www.openejb.org/xml/ns/openejb-jar-2.1"
xmlns:nam="http://geronimo.apache.org/xml/ns/naming-1.1"
xmlns:pkgen="http://www.openejb.org/xml/ns/pkgen-2.0"
xmlns:sec="http://geronimo.apache.org/xml/ns/security-1.1"
xmlns:sys="http://geronimo.apache.org/xml/ns/deployment-1.2">
<sys:environment>
<sys:moduleId>
<sys:groupId>o2o.marketing</sys:groupId>
<sys:artifactId>EJB</sys:artifactId>
<sys:version>1.0.8</sys:version>
<sys:type>jar</sys:type>
</sys:moduleId>
<sys:dependencies>
<sys:dependency>
<sys:groupId>console.dbpool</sys:groupId>
<sys:artifactId>marketing</sys:artifactId>
<sys:version>1.0</sys:version>
<sys:type>rar</sys:type>
</sys:dependency>
</sys:dependencies>
</sys:environment>
</openejb-jar>
And I have also persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
<persistence-unit name="marketing">
<description>Entity Beans for User</description>
<provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
<jta-data-source>java:comp/env/marketing</jta-data-source>
<non-jta-data-source>java:comp/env/marketing</non-jta-data-source>
<mapping-file>META-INF/orm.xml</mapping-file>
<properties />
</persistence-unit>
</persistence>
The error which I'm having is the next one: Unable to resolve reference
"JtaDataSourceWrapper" and Unable to resolve reference
"NonJtaDataSourceWrapper", which are basically the same error.
I think this is produced because I'm not mapping the Datasocurce to the
DBPool. Geronimo returns to me examples to do it for web, but no example to
do it for an EJB.
Please could you help me?
WATCH OUT! I'm talking about entities and EJB3.0, not entiti beans and
EJB2.0
Thanks in advance
SERGIO
--
View this message in context: http://www.nabble.com/JPA%2C-entities-and-EJB3-tp17502079s134p17502079.html
Sent from the Apache Geronimo - Users mailing list archive at Nabble.com.
Re: JPA, entities and EJB3
Posted by David Blevins <da...@visi.com>.
Definitely if you intend to use UserTransaction I would absolutely go
with a TRANSACTION scoped unit and then use @PersistenceContext
EntityManager. Once you call joinTransaction you end up paying the
cost of a JTA transaction but don't get any of the benefits. One of
those benefits would make it impossible for you to make the mistake
you made. Very good learning experience though, and you're lucky you
found this quickly!
In this particular code that you posted you're creating two
EntityManagers in the same JTA transaction and they are competing
against each other. As I mentioned, EntityManagers created from a
RESOURCE_LOCAL/EntityManagerFactory do not cooperate with anyone.
Each EntityManager represents a cache and has it's own non-shared
database connection, etc.
So here's what the implications of that are, for simplification
reasons we'll say the accountNumber variable is 12345:
- Method1: you create a private database Cache, we'll call it
PersistenceContext A (i.e. you create an EntityManager)
- Method1: a JTA transaction is begin via UserTransaction.begin();
- Method1: you call joinTransaction on PersistenceContext A
instructing it to flush it's cache when the JTA transaction ends.
- Method1: you ask PersistenceContext A to find Account 12345,
PersistenceContext A does yet have a copy of that date, thus it will
pull the data from the database and into the cache of
PersistenceContext A.
- Method1: updates to Account 12345 are done against the *cached
copy* in PersistenceContext A.
- Method2: you create a *second* private database Cache,
PersistenceContext B (i.e. you create an EntityManager)
- Method2: you call joinTransaction on PersistenceContext B
instructing it to flush it's cache when the JTA transaction ends.
- Method2: you ask PersistenceContext B to find Account 12345,
PersistenceContext B does yet have a copy of that date, thus it will
pull the data from the database and into the cache of
PersistenceContext B. You now have *two* separate and competing
copies of Account 1234 in the transaction, in in the cache of
PersistenceContext A and one in the cache of PersistenceContext B.
- Method2: updates to Account 12345 are done against the *cached
copy* in PersistenceContext B.
- Method1: more up to Account 12345 are done against the *cached
copy* in PersistenceContext A.
- Method1: the JTA transaction is committed and PersistenceContext A
and PersistenceContext B are each individually notified to flush their
caches.
At this point there's no guarantee who will win, A or B. But based on
your results it's pretty clear A got to the database before B,
therefore B was the last person to update the record. I.e.:
- PersistenceContext A flushed it's cache and executed "ACCOUNT
12345 BALANCE = 7000"
- Then PersistenceContext B flushed it's cache and executed "ACCOUNT
12345 BALANCE = 6000"
So the moral of this story is that the concept of a database cache is
an extremely important concept to be aware of. Without a copy of the
data in memory (i.e. a cache) when you call account.getBalance() the
persistence provider would have to go read the value from the database
every time. This would obviously be a big waste of resources. The
other side of having a cache is that when you call
account.setBalance(5000) it also doesn't hit the database (usually).
When the cache is "flushed" the data in it is sent to the database via
as many SQL updates, inserts and deletes as are required. That is the
basics of java persistence of any kind all wrapped in a nutshell. If
you can understand that, you're good to go in nearly any persistence
technology java has to offer.
With this in mind, the explanation I posted before will likely take on
a whole new light. Here's a slightly reworded/abbreviated version:
A RESOURCE_LOCAL persistence unit: The implication of the
RESOURCE_LOCAL is that the EntityManager instance you create from the
factory *is* the entire persistence context, cache and all. For
illustrative purposes it's safe to imagine big "cache" hashmap as a
field inside the EntityManager instance you created. If you want
someone else to do persistent operations with the same persistence
context you need to find a way to get them the exact EntityManager
instance you created (not a second EntityManager they create).
A TRANSACTION persistence unit: With TRANSACTION, everyone in the
transaction shares the same EntityMangaer. As a vendor what we do
underneath the covers is give you an EntityManager wrapper that points
to nothing. Then when a transaction is started (via UserTransaction
or a container transaction) we use the EntityManagerFactory to create
an EntityManager instance and make all the wrappers point to it. When
the transaction commits, the cache associated with the internal
EntityManager instance is flushed and the EntityManager instance is
discarded and all EntityManager wrappers again point to nothing. This
is essentially why you need a transaction in progress to use a
EntityManager with JTA scope and TRANSACTION unit, because the
EntityManager you hold onto doesn't represent a real EntityManager
rather just a "fake" EntityManager that directs all calls you make on
it to the container's internal EntityManager that is associated with
the JTA transaction you're in. If there is no JTA transaction in
progress, there is no internal EntityManager and the EnityManager
wrappers therefore point nowhere.
-David
On Jun 12, 2008, at 5:02 AM, Phani Madgula wrote:
> Thanks for providing useful. Now the intricacies are becoming clear
> indeed !!
> I am trying to guess what could/should be the outcome of the
> following scenario.
>
> ***************
> @PersistenceUnit(unitName="AccountUnit")
> EntityManagerFactory emf;
>
> [..]
> private void method1(int accountNumber, PrintWriter out)
> throws Exception{
>
> try{
> EntityManager em = emf.createEntityManager();
>
> Context ctx = new InitialContext();
> UserTransaction ut =
> (UserTransaction)ctx.lookup("java:comp/UserTransaction");
>
> ut.begin();
>
> em.joinTransaction();
>
> Account account = em.find(Account.class, accountNumber);
>
> account.setBalance(5000);
>
> method2(accountNumber,out);
>
> account.setBalance(7000); (this update is missing in the
> table)
>
> ut.commit();
>
>
> }catch(Exception e){
> throw e;
> }
> }
>
> private void method2(int accountNumber, PrintWriter out)throws
> Exception {
>
> try{
> EntityManager em = emf.createEntityManager();
>
> em.joinTransaction();
>
> Account account = em.find(Account.class, accountNumber);
>
> account.setBalance(6000);
>
>
> }catch(Exception e){
> throw e;
> }
>
> }
> ********************************
>
> What I observed from the above code is account.setBalance(7000);
> (this update is missing in the table). The value of balance column
> will be 6000. The last update in the method (to 7000) misses.
>
> Thanks
> Phani
>
> On Thu, Jun 12, 2008 at 7:44 AM, David Blevins
> <da...@visi.com> wrote:
>
>
> On Jun 9, 2008, at 1:43 AM, Phani Madgula wrote:
>
> Hi,
> I have tried to play with <jta-datasource> and <non-jta-datasource>
> as follows.
>
> I have the following peristence.xml in a web application.
> [...]
>
>
> <persistence-unit name="Tutorial" transaction-type="RESOURCE_LOCAL">
> [...]
>
>
> In the servlet, I have the following code
> [...]
>
> @PersistenceContext(unitName="Tutorial")
> private EntityManager em;
> .....
> ....
> UserTransaction ut;
> try{
> Context ctx = new InitialContext();
>
> //ut = (UserTransaction)ctx.lookup("java:comp/
> UserTransaction");
> //ut.begin();
>
> //Uncomment EntityTransaction
> EntityTransaction et = em.getTransaction();
> et.begin();
>
> Book book = new Book("DDDDD","John",
> 1.0,"Joe","1934834-23823","Phani");
> em.persist(book);
>
> et.commit();
> //ut.commit();
>
> }catch(Exception e){
> e.printStackTrace();
> throw new ServletException (e);
> }
> ***********************
> I get the following error
> ***********************
>
> java.lang.IllegalStateException : You can not call getTransaction on
> a container managed EntityManager
>
> [...]
>
>
> Please note that I am using "RESOURCE_LOCAL" persistence unit.
>
> You're in the right direction. Try modifying this part of your
> servlet as follows:
>
> [cut this part]
>
> @PersistenceContext(unitName="Tutorial")
> private EntityManager em;
>
> [redo as]
> @PersistenceUnit(unitName="Tutorial")
> private EntityManagerFactory emf;
>
>
> The use of RESOURCE_LOCAL definitely requires you to use the
> EntityTransaction API as you were attempting to do. It also
> requires you to use the EntityManagerFactory to get your
> EntityManager. The implication of the RESOURCE_LOCAL is that the
> EntityManager instance you create from the factory *is* the entire
> persistence context, cache and all (EntityManger instance ==
> PersistenceContext, terminology wise). For illustrative purposes
> it's safe to imagine big "cache" hashmap as a field inside the
> EntityManager instance you created. It's not entirely how most
> providers do it, but the technical ramifications are the same. One
> of the ramifications is that if you want someone else to do
> persistent operations with the same persistence context you need to
> find a way to get them the EntityManager instance you created. From
> a spec perspective we (EJB 3.0 spec hat on) could have allowed you
> to reference a RESOURCE_LOCAL unit via an EntityManager reference,
> but the trick is that each reference would wind up creating a new
> EntityManager instance, cache and all, and you could make a really
> big mess; seemed better to just force you to create the instance
> yourself and share it however you feel best so that there could be
> no misunderstandings.
>
> With a TRANSACTION unit you are in fact required to lookup or have
> injected the EntityManager and are not allowed to use the
> EntityManagerFactory or the EntityTransaction API. As a vendor what
> we do underneath the covers is give you an EntityManager wrapper
> that points to nothing. Then when a transaction is started (via
> UserTransaction or a container transaction) we use the
> EntityManagerFactory to create an EntityManager instance and make
> all the wrappers point to it. When the transaction commits, the
> internal EntityManager instance is discarded (cache goes bye-bye)
> and wrappers again point to nothing. This is essentially why you
> need a transaction in progress to use a EntityManager with JTA scope
> and TRANSACTION unit. With an EXTENDED PersistenceContext (again,
> available only with a TRANSACTION unit) things work pretty much the
> same except that the internal EntityManager instance is *not*
> discarded and the end of transactions (cache stays in memory and can
> be used again in another transaction), instead it lives as long as
> the Stateful session bean holding it.
>
>
> My questions are
>
> 1. Should we always use UserTransaction object irrespective of
> <jta-datasource> or <non-jta-datasource> in JEE environment??
>
> 2. How is the use of <non-jta-datsource> different from the use
> <jta-datasource> in JEE environment??
>
> 3. In EJBs, when ContainerManaged Transactions are used, there is no
> need to use JTA. Is that correct??
>
> 4. Only in J2SE environments, we can use EntityTransaction object. is
> that correct??
>
> Hopefully the above explanation answers these questions (good
> questions, BTW). If anything is still unclear, definitely don't
> hesitate to ask for more information or for something to be simply
> reworded (can be hard trying to find the right way to explain these
> things).
>
>
> -David
>
>
> On 5/28/08, David Jencks <da...@yahoo.com> wrote:
> 1. I hope you named the file openejb-jar.xml
> 2. jta-datasource and non-jta-datasource have to contain the names of
> the datasources in the geronimo plan used for the pool, NOT some jndi
> name you might also map them to. The datasources don't need to be
> bound in jndi in order to be used for jpa
> 3. The non-jta-datasource must be a datasource that really has no
> transaction support, using the <no-transaction/> element instead of
> <local-transaction/> or <xa-transaction>... in the connector plan.
> With derby I find it necessary to have a non-jta-datasource if any ddl
> is needed or if openjpa is generating the primary keys. I don't know
> if you can get away without one for other databases. If you want to
> experiment, leave out the non-jta-datasource rather than duplicating
> the jta-datasource contents.
>
> hope this helps
> david jencks
>
> On May 27, 2008, at 4:09 PM, zeros wrote:
>
>
> Good evening:
>
> I'm newbie with EJB3.0. I want to configure the persistence.xml
> to have
> entities managed with JPA. I have the next configuration files:
> OPENJPA-JAR.XML
>
> <openejb-jar xmlns="http://www.openejb.org/xml/ns/openejb-jar-2.1"
> xmlns:nam="http://geronimo.apache.org/xml/ns/naming-1.1"
> xmlns:pkgen="http://www.openejb.org/xml/ns/pkgen-2.0"
> xmlns:sec="http://geronimo.apache.org/xml/ns/security-1.1"
> xmlns:sys="http://geronimo.apache.org/xml/ns/deployment-1.2">
> <sys:environment>
> <sys:moduleId>
> <sys:groupId>o2o.marketing</sys:groupId>
> <sys:artifactId>EJB</sys:artifactId>
> <sys:version>1.0.8</sys:version>
> <sys:type>jar</sys:type>
> </sys:moduleId>
> <sys:dependencies>
> <sys:dependency>
> <sys:groupId>console.dbpool</sys:groupId>
> <sys:artifactId>marketing</sys:artifactId>
> <sys:version>1.0</sys:version>
> <sys:type>rar</sys:type>
> </sys:dependency>
> </sys:dependencies>
> </sys:environment>
> </openejb-jar>
>
> And I have also persistence.xml
>
> <?xml version="1.0" encoding="UTF-8"?>
> <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence
> "
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
> <persistence-unit name="marketing">
> <description>Entity Beans for User</description>
>
> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</
> provider>
> <jta-data-source>java:comp/env/marketing</jta-data-source>
> <non-jta-data-source>java:comp/env/marketing</non-jta-data-
> source>
> <mapping-file>META-INF/orm.xml</mapping-file>
> <properties />
> </persistence-unit>
> </persistence>
>
> The error which I'm having is the next one: Unable to resolve
> reference
> "JtaDataSourceWrapper" and Unable to resolve reference
> "NonJtaDataSourceWrapper", which are basically the same error.
>
> I think this is produced because I'm not mapping the Datasocurce to
> the
> DBPool. Geronimo returns to me examples to do it for web, but no
> example to
> do it for an EJB.
>
> Please could you help me?
>
> WATCH OUT! I'm talking about entities and EJB3.0, not entiti beans and
> EJB2.0
>
> Thanks in advance
>
> SERGIO
> --
> View this message in context:
> http://www.nabble.com/JPA%2C-entities-and-EJB3-tp17502079s134p17502079.html
> Sent from the Apache Geronimo - Users mailing list archive at
> Nabble.com.
>
>
>
>
>
>
Re: JPA, entities and EJB3
Posted by Phani Madgula <ph...@gmail.com>.
Thanks for providing useful. Now the intricacies are becoming clear indeed
!!
I am trying to guess what could/should be the outcome of the following
scenario.
***************
@PersistenceUnit(unitName="AccountUnit")
EntityManagerFactory emf;
[..]
private void method1(int accountNumber, PrintWriter out)
throws Exception{
try{
EntityManager em = emf.createEntityManager();
Context ctx = new InitialContext();
UserTransaction ut =
(UserTransaction)ctx.lookup("java:comp/UserTransaction");
ut.begin();
em.joinTransaction();
Account account = em.find(Account.class, accountNumber);
account.setBalance(5000);
method2(accountNumber,out);
*account.setBalance(7000); (this update is missing in the table)
*
ut.commit();
}catch(Exception e){
throw e;
}
}
private void method2(int accountNumber, PrintWriter out)throws Exception
{
try{
EntityManager em = emf.createEntityManager();
em.joinTransaction();
Account account = em.find(Account.class, accountNumber);
account.setBalance(6000);
}catch(Exception e){
throw e;
}
}
********************************
What I observed from the above code is *account.setBalance(7000); (this
update is missing in the table). The value of balance column will be 6000.
The last update in the method (to 7000) misses.
Thanks
Phani
*
On Thu, Jun 12, 2008 at 7:44 AM, David Blevins <da...@visi.com>
wrote:
>
>
> On Jun 9, 2008, at 1:43 AM, Phani Madgula wrote:
>
> Hi,
>> I have tried to play with <jta-datasource> and <non-jta-datasource> as
>> follows.
>>
>> I have the following peristence.xml in a web application.
>>
> [...]
>
>>
>> <persistence-unit name="Tutorial" transaction-type="RESOURCE_LOCAL">
>>
> [...]
>
> In the servlet, I have the following code
>>
> [...]
>
>>
>> @PersistenceContext(unitName="Tutorial")
>> private EntityManager em;
>> .....
>> ....
>> UserTransaction ut;
>> try{
>> Context ctx = new InitialContext();
>>
>> //ut =
>> (UserTransaction)ctx.lookup("java:comp/UserTransaction");
>> //ut.begin();
>>
>> //Uncomment EntityTransaction
>> EntityTransaction et = em.getTransaction();
>> et.begin();
>>
>> Book book = new
>> Book("DDDDD","John",1.0,"Joe","1934834-23823","Phani");
>> em.persist(book);
>>
>> et.commit();
>> //ut.commit();
>>
>> }catch(Exception e){
>> e.printStackTrace();
>> throw new ServletException (e);
>> }
>> ***********************
>> I get the following error
>> ***********************
>>
>> java.lang.IllegalStateException : You can not call getTransaction on
>> a container managed EntityManager
>>
>
> [...]
>
> Please note that I am using "RESOURCE_LOCAL" persistence unit.
>>
>
> You're in the right direction. Try modifying this part of your servlet as
> follows:
>
> [cut this part]
> @PersistenceContext(unitName="Tutorial")
> private EntityManager em;
>
> [redo as]
> @PersistenceUnit(unitName="Tutorial")
> private EntityManagerFactory emf;
>
>
> The use of RESOURCE_LOCAL definitely requires you to use the
> EntityTransaction API as you were attempting to do. It also requires you to
> use the EntityManagerFactory to get your EntityManager. The implication of
> the RESOURCE_LOCAL is that the EntityManager instance you create from the
> factory *is* the entire persistence context, cache and all (EntityManger
> instance == PersistenceContext, terminology wise). For illustrative
> purposes it's safe to imagine big "cache" hashmap as a field inside the
> EntityManager instance you created. It's not entirely how most providers do
> it, but the technical ramifications are the same. One of the ramifications
> is that if you want someone else to do persistent operations with the same
> persistence context you need to find a way to get them the EntityManager
> instance you created. From a spec perspective we (EJB 3.0 spec hat on)
> could have allowed you to reference a RESOURCE_LOCAL unit via an
> EntityManager reference, but the trick is that each reference would wind up
> creating a new EntityManager instance, cache and all, and you could make a
> really big mess; seemed better to just force you to create the instance
> yourself and share it however you feel best so that there could be no
> misunderstandings.
>
> With a TRANSACTION unit you are in fact required to lookup or have injected
> the EntityManager and are not allowed to use the EntityManagerFactory or the
> EntityTransaction API. As a vendor what we do underneath the covers is give
> you an EntityManager wrapper that points to nothing. Then when a
> transaction is started (via UserTransaction or a container transaction) we
> use the EntityManagerFactory to create an EntityManager instance and make
> all the wrappers point to it. When the transaction commits, the internal
> EntityManager instance is discarded (cache goes bye-bye) and wrappers again
> point to nothing. This is essentially why you need a transaction in
> progress to use a EntityManager with JTA scope and TRANSACTION unit. With
> an EXTENDED PersistenceContext (again, available only with a TRANSACTION
> unit) things work pretty much the same except that the internal
> EntityManager instance is *not* discarded and the end of transactions (cache
> stays in memory and can be used again in another transaction), instead it
> lives as long as the Stateful session bean holding it.
>
> My questions are
>>
>> 1. Should we always use UserTransaction object irrespective of
>> <jta-datasource> or <non-jta-datasource> in JEE environment??
>>
>> 2. How is the use of <non-jta-datsource> different from the use
>> <jta-datasource> in JEE environment??
>>
>> 3. In EJBs, when ContainerManaged Transactions are used, there is no
>> need to use JTA. Is that correct??
>>
>> 4. Only in J2SE environments, we can use EntityTransaction object. is
>> that correct??
>>
>
> Hopefully the above explanation answers these questions (good questions,
> BTW). If anything is still unclear, definitely don't hesitate to ask for
> more information or for something to be simply reworded (can be hard trying
> to find the right way to explain these things).
>
>
> -David
>
>
> On 5/28/08, David Jencks <da...@yahoo.com> wrote:
>>
>>> 1. I hope you named the file openejb-jar.xml
>>> 2. jta-datasource and non-jta-datasource have to contain the names of
>>> the datasources in the geronimo plan used for the pool, NOT some jndi
>>> name you might also map them to. The datasources don't need to be
>>> bound in jndi in order to be used for jpa
>>> 3. The non-jta-datasource must be a datasource that really has no
>>> transaction support, using the <no-transaction/> element instead of
>>> <local-transaction/> or <xa-transaction>... in the connector plan.
>>> With derby I find it necessary to have a non-jta-datasource if any ddl
>>> is needed or if openjpa is generating the primary keys. I don't know
>>> if you can get away without one for other databases. If you want to
>>> experiment, leave out the non-jta-datasource rather than duplicating
>>> the jta-datasource contents.
>>>
>>> hope this helps
>>> david jencks
>>>
>>> On May 27, 2008, at 4:09 PM, zeros wrote:
>>>
>>>
>>>> Good evening:
>>>>
>>>> I'm newbie with EJB3.0. I want to configure the persistence.xml
>>>> to have
>>>> entities managed with JPA. I have the next configuration files:
>>>> OPENJPA-JAR.XML
>>>>
>>>> <openejb-jar xmlns="http://www.openejb.org/xml/ns/openejb-jar-2.1"
>>>> xmlns:nam="http://geronimo.apache.org/xml/ns/naming-1.1"
>>>> xmlns:pkgen="http://www.openejb.org/xml/ns/pkgen-2.0"
>>>> xmlns:sec="http://geronimo.apache.org/xml/ns/security-1.1"
>>>> xmlns:sys="http://geronimo.apache.org/xml/ns/deployment-1.2">
>>>> <sys:environment>
>>>> <sys:moduleId>
>>>> <sys:groupId>o2o.marketing</sys:groupId>
>>>> <sys:artifactId>EJB</sys:artifactId>
>>>> <sys:version>1.0.8</sys:version>
>>>> <sys:type>jar</sys:type>
>>>> </sys:moduleId>
>>>> <sys:dependencies>
>>>> <sys:dependency>
>>>> <sys:groupId>console.dbpool</sys:groupId>
>>>> <sys:artifactId>marketing</sys:artifactId>
>>>> <sys:version>1.0</sys:version>
>>>> <sys:type>rar</sys:type>
>>>> </sys:dependency>
>>>> </sys:dependencies>
>>>> </sys:environment>
>>>> </openejb-jar>
>>>>
>>>> And I have also persistence.xml
>>>>
>>>> <?xml version="1.0" encoding="UTF-8"?>
>>>> <persistence version="1.0" xmlns="
>>>> http://java.sun.com/xml/ns/persistence
>>>> "
>>>> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>>>> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
>>>> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
>>>> <persistence-unit name="marketing">
>>>> <description>Entity Beans for User</description>
>>>>
>>>> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</
>>>> provider>
>>>> <jta-data-source>java:comp/env/marketing</jta-data-source>
>>>>
>>>> <non-jta-data-source>java:comp/env/marketing</non-jta-data-source>
>>>> <mapping-file>META-INF/orm.xml</mapping-file>
>>>> <properties />
>>>> </persistence-unit>
>>>> </persistence>
>>>>
>>>> The error which I'm having is the next one: Unable to resolve
>>>> reference
>>>> "JtaDataSourceWrapper" and Unable to resolve reference
>>>> "NonJtaDataSourceWrapper", which are basically the same error.
>>>>
>>>> I think this is produced because I'm not mapping the Datasocurce to
>>>> the
>>>> DBPool. Geronimo returns to me examples to do it for web, but no
>>>> example to
>>>> do it for an EJB.
>>>>
>>>> Please could you help me?
>>>>
>>>> WATCH OUT! I'm talking about entities and EJB3.0, not entiti beans and
>>>> EJB2.0
>>>>
>>>> Thanks in advance
>>>>
>>>> SERGIO
>>>> --
>>>> View this message in context:
>>>>
>>>> http://www.nabble.com/JPA%2C-entities-and-EJB3-tp17502079s134p17502079.html
>>>> Sent from the Apache Geronimo - Users mailing list archive at
>>>> Nabble.com.
>>>>
>>>>
>>>
>>>
>>
>
Re: JPA, entities and EJB3
Posted by David Blevins <da...@visi.com>.
On Jun 9, 2008, at 1:43 AM, Phani Madgula wrote:
> Hi,
> I have tried to play with <jta-datasource> and <non-jta-datasource>
> as follows.
>
> I have the following peristence.xml in a web application.
[...]
>
> <persistence-unit name="Tutorial" transaction-
> type="RESOURCE_LOCAL">
[...]
> In the servlet, I have the following code
[...]
>
> @PersistenceContext(unitName="Tutorial")
> private EntityManager em;
> .....
> ....
> UserTransaction ut;
> try{
> Context ctx = new InitialContext();
>
> //ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
> //ut.begin();
>
> //Uncomment EntityTransaction
> EntityTransaction et = em.getTransaction();
> et.begin();
>
> Book book = new Book("DDDDD","John",
> 1.0,"Joe","1934834-23823","Phani");
> em.persist(book);
>
> et.commit();
> //ut.commit();
>
> }catch(Exception e){
> e.printStackTrace();
> throw new ServletException (e);
> }
> ***********************
> I get the following error
> ***********************
>
> java.lang.IllegalStateException : You can not call getTransaction on
> a container managed EntityManager
[...]
> Please note that I am using "RESOURCE_LOCAL" persistence unit.
You're in the right direction. Try modifying this part of your
servlet as follows:
[cut this part]
@PersistenceContext(unitName="Tutorial")
private EntityManager em;
[redo as]
@PersistenceUnit(unitName="Tutorial")
private EntityManagerFactory emf;
The use of RESOURCE_LOCAL definitely requires you to use the
EntityTransaction API as you were attempting to do. It also requires
you to use the EntityManagerFactory to get your EntityManager. The
implication of the RESOURCE_LOCAL is that the EntityManager instance
you create from the factory *is* the entire persistence context, cache
and all (EntityManger instance == PersistenceContext, terminology
wise). For illustrative purposes it's safe to imagine big "cache"
hashmap as a field inside the EntityManager instance you created.
It's not entirely how most providers do it, but the technical
ramifications are the same. One of the ramifications is that if you
want someone else to do persistent operations with the same
persistence context you need to find a way to get them the
EntityManager instance you created. From a spec perspective we (EJB
3.0 spec hat on) could have allowed you to reference a RESOURCE_LOCAL
unit via an EntityManager reference, but the trick is that each
reference would wind up creating a new EntityManager instance, cache
and all, and you could make a really big mess; seemed better to just
force you to create the instance yourself and share it however you
feel best so that there could be no misunderstandings.
With a TRANSACTION unit you are in fact required to lookup or have
injected the EntityManager and are not allowed to use the
EntityManagerFactory or the EntityTransaction API. As a vendor what
we do underneath the covers is give you an EntityManager wrapper that
points to nothing. Then when a transaction is started (via
UserTransaction or a container transaction) we use the
EntityManagerFactory to create an EntityManager instance and make all
the wrappers point to it. When the transaction commits, the internal
EntityManager instance is discarded (cache goes bye-bye) and wrappers
again point to nothing. This is essentially why you need a
transaction in progress to use a EntityManager with JTA scope and
TRANSACTION unit. With an EXTENDED PersistenceContext (again,
available only with a TRANSACTION unit) things work pretty much the
same except that the internal EntityManager instance is *not*
discarded and the end of transactions (cache stays in memory and can
be used again in another transaction), instead it lives as long as the
Stateful session bean holding it.
> My questions are
>
> 1. Should we always use UserTransaction object irrespective of
> <jta-datasource> or <non-jta-datasource> in JEE environment??
>
> 2. How is the use of <non-jta-datsource> different from the use
> <jta-datasource> in JEE environment??
>
> 3. In EJBs, when ContainerManaged Transactions are used, there is no
> need to use JTA. Is that correct??
>
> 4. Only in J2SE environments, we can use EntityTransaction object. is
> that correct??
Hopefully the above explanation answers these questions (good
questions, BTW). If anything is still unclear, definitely don't
hesitate to ask for more information or for something to be simply
reworded (can be hard trying to find the right way to explain these
things).
-David
> On 5/28/08, David Jencks <da...@yahoo.com> wrote:
>> 1. I hope you named the file openejb-jar.xml
>> 2. jta-datasource and non-jta-datasource have to contain the names of
>> the datasources in the geronimo plan used for the pool, NOT some jndi
>> name you might also map them to. The datasources don't need to be
>> bound in jndi in order to be used for jpa
>> 3. The non-jta-datasource must be a datasource that really has no
>> transaction support, using the <no-transaction/> element instead of
>> <local-transaction/> or <xa-transaction>... in the connector plan.
>> With derby I find it necessary to have a non-jta-datasource if any
>> ddl
>> is needed or if openjpa is generating the primary keys. I don't know
>> if you can get away without one for other databases. If you want to
>> experiment, leave out the non-jta-datasource rather than duplicating
>> the jta-datasource contents.
>>
>> hope this helps
>> david jencks
>>
>> On May 27, 2008, at 4:09 PM, zeros wrote:
>>
>>>
>>> Good evening:
>>>
>>> I'm newbie with EJB3.0. I want to configure the persistence.xml
>>> to have
>>> entities managed with JPA. I have the next configuration files:
>>> OPENJPA-JAR.XML
>>>
>>> <openejb-jar xmlns="http://www.openejb.org/xml/ns/openejb-jar-2.1"
>>> xmlns:nam="http://geronimo.apache.org/xml/ns/naming-1.1"
>>> xmlns:pkgen="http://www.openejb.org/xml/ns/pkgen-2.0"
>>> xmlns:sec="http://geronimo.apache.org/xml/ns/security-1.1"
>>> xmlns:sys="http://geronimo.apache.org/xml/ns/deployment-1.2">
>>> <sys:environment>
>>> <sys:moduleId>
>>> <sys:groupId>o2o.marketing</sys:groupId>
>>> <sys:artifactId>EJB</sys:artifactId>
>>> <sys:version>1.0.8</sys:version>
>>> <sys:type>jar</sys:type>
>>> </sys:moduleId>
>>> <sys:dependencies>
>>> <sys:dependency>
>>> <sys:groupId>console.dbpool</sys:groupId>
>>> <sys:artifactId>marketing</sys:artifactId>
>>> <sys:version>1.0</sys:version>
>>> <sys:type>rar</sys:type>
>>> </sys:dependency>
>>> </sys:dependencies>
>>> </sys:environment>
>>> </openejb-jar>
>>>
>>> And I have also persistence.xml
>>>
>>> <?xml version="1.0" encoding="UTF-8"?>
>>> <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence
>>> "
>>> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>>> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
>>> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
>>> <persistence-unit name="marketing">
>>> <description>Entity Beans for User</description>
>>>
>>> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</
>>> provider>
>>> <jta-data-source>java:comp/env/marketing</jta-data-source>
>>> <non-jta-data-source>java:comp/env/marketing</non-jta-data-
>>> source>
>>> <mapping-file>META-INF/orm.xml</mapping-file>
>>> <properties />
>>> </persistence-unit>
>>> </persistence>
>>>
>>> The error which I'm having is the next one: Unable to resolve
>>> reference
>>> "JtaDataSourceWrapper" and Unable to resolve reference
>>> "NonJtaDataSourceWrapper", which are basically the same error.
>>>
>>> I think this is produced because I'm not mapping the Datasocurce to
>>> the
>>> DBPool. Geronimo returns to me examples to do it for web, but no
>>> example to
>>> do it for an EJB.
>>>
>>> Please could you help me?
>>>
>>> WATCH OUT! I'm talking about entities and EJB3.0, not entiti beans
>>> and
>>> EJB2.0
>>>
>>> Thanks in advance
>>>
>>> SERGIO
>>> --
>>> View this message in context:
>>> http://www.nabble.com/JPA%2C-entities-and-EJB3-tp17502079s134p17502079.html
>>> Sent from the Apache Geronimo - Users mailing list archive at
>>> Nabble.com.
>>>
>>
>>
>
Re: JPA, entities and EJB3
Posted by Phani Madgula <ph...@gmail.com>.
Here is what I observed.
1. If @PersistenceContext(unitName="Tutorial") is used, irrespective of
"transaction-type" (JTA or RESOURCE_LOCAL) the ContainerManaged EM is
returned. UserTransaction object should be used to perform transactions.
Because, if EntityTransaction object is used, the server throws exception.
The persistence context is carried over by JTA transaction during the life
of the transaction. In this case, if the value "RESOURCE_LOCAL" is used for
"transaction-type" the commits will not happen. I think the value "JTA" for
transaction-type attribute only makes sense??
2. if @PeristenceUnit(unitName="Tutorial") is used and the value of
transaction-type is RESOURCE_LOCAL, whenever EM is obtained from EMF, a new
persistence context is returned. EntityTransaction object should be used to
perform transactions. Using UserTransaction Object does not commit the
values.
3. if @PeristenceUnit(unitName="Tutorial") is used and the value of
transaction-type is JTA, whenever EM is obtained from EMF, a new persistence
context is returned. EntityTransaction object can not be used. The server
throws exception. Only UserTransaction object can be used. Even though, a
new PeristenceContext is obtained every time EM is got from the EMF, the
last update made to an entity (irrespective of which PersistenceContext made
the update) is committed to the database.
I am confused as to where the above scenarios come into play in real world
applications. But I do understand ContainerManaged EM + JTA and
ApplicationManaged EM + RESOURCE_LOCAL combinations. Request clarification
on other combinations??
Thanks
Phani
On Tue, Jun 10, 2008 at 9:23 AM, Phani Madgula <
phanibalaji.madgula@gmail.com> wrote:
> Thanks for the info. I looked into Spec and got a very vague idea of what's
> happening here. Let me test these scenarios with some samples and understand
> what's happening.
>
> Thanks
> Phani
>
>
> On Mon, Jun 9, 2008 at 11:35 PM, David Jencks <da...@yahoo.com>
> wrote:
>
>> I looked in the spec a bit and am not sure I understand how all the parts
>> are meshing, maybe david blevins can chime in... I think that you've
>> specified contradictory information and maybe we should be complaining
>> rather than supplying a container managed jta EntityManager.
>> I _think_ that your annotation-injected EntityManager has to be container
>> managed and hence jta.
>> I _think_ that if you want a resource-local EntityManager you have to
>> inject the EMF with a PersistenceUnit annotation and get the EntityManager
>> yourself.
>>
>> In the spec, section 5.6 starts:
>> Whenacontainer-managedentitymanager isused, thelifecycleof
>> thepersistencecontext isalways
>> managedautomatically, transparentlytotheapplication,
>> andthepersistencecontextispropagatedwith
>> the JTA transaction.
>>
>>
>> I think this means that with your @PersistenceContext annotation, you are
>> definitely going to get a tx-type=JTA EM. Since you specified
>> RESOURCE_LOCAL in the persistence.xml I think we should perhaps be
>> objecting.
>>
>> I also think this means that you need an application managed persistence
>> context to get RESOURCE_LOCAL. There are a bunch of examples in section 5.7
>> that all use @PersistenceUnit.
>>
>> Also hoping for clarification....
>> david jencks
>>
>> On Jun 9, 2008, at 1:43 AM, Phani Madgula wrote:
>>
>> Hi,
>> I have tried to play with <jta-datasource> and <non-jta-datasource> as
>> follows.
>>
>> I have the following peristence.xml in a web application.
>> ***********
>> <?xml version="1.0" encoding="UTF-8" ?>
>> <persistence xmlns="http://java.sun.com/xml/ns/persistence"
>> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
>> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
>> version="1.0">
>>
>> <!-- Tutorial "unit" -->
>> <persistence-unit name="Tutorial" transaction-type="RESOURCE_LOCAL">
>>
>> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
>> <non-jta-data-source>ProductDS-nonJTA</non-jta-data-source>
>> <mapping-file>orm.xml</mapping-file>
>> <class>samples.jpa.Product</class>
>> <class>samples.jpa.Book</class>
>>
>> </persistence-unit>
>>
>> </persistence>
>>
>> ***********
>>
>> In the servlet, I have the following code
>>
>> ***********
>> @PersistenceContext(unitName="Tutorial")
>> private EntityManager em;
>> .....
>> ....
>> UserTransaction ut;
>> try{
>> Context ctx = new InitialContext();
>>
>> //ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
>> //ut.begin();
>>
>> //EntityTransaction et = em.getTransaction();
>> //et.begin();
>>
>> Book book = new Book("DDDDD","John",1.0,"Joe","1934834-23823","Phani");
>> em.persist(book);
>>
>> //et.commit();
>> //ut.commit();
>>
>> }catch(Exception e){
>> e.printStackTrace();
>> throw new ServletException (e);
>> }
>> ***********************
>>
>> 1. When I hit the servlet, I get the following error.
>>
>> ***********************
>> javax.persistence.TransactionRequiredException : No Active transaction
>> ***********************
>>
>> 2. Suppose I have the following code in the servlet
>> **********************
>> ***********
>> @PersistenceContext(unitName="Tutorial")
>> private EntityManager em;
>> .....
>> ....
>> UserTransaction ut;
>> try{
>> Context ctx = new InitialContext();
>>
>> //ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
>> //ut.begin();
>>
>> //Uncomment EntityTransaction
>> EntityTransaction et = em.getTransaction();
>> et.begin();
>>
>> Book book = new Book("DDDDD","John",1.0,"Joe","1934834-23823","Phani");
>> em.persist(book);
>>
>> et.commit();
>> //ut.commit();
>>
>> }catch(Exception e){
>> e.printStackTrace();
>> throw new ServletException (e);
>> }
>> ***********************
>> I get the following error
>> ***********************
>>
>> java.lang.IllegalStateException : You can not call getTransaction on
>> a container managed EntityManager
>>
>> *************************
>>
>> 3. Only if I use JTA API, I am able to get the entity persisted
>> properly as below.
>> ***************************
>> @PersistenceContext(unitName="Tutorial")
>> private EntityManager em;
>> .....
>> ....
>> UserTransaction ut;
>> try{
>> Context ctx = new InitialContext();
>>
>> ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
>> ut.begin();
>>
>>
>> Book book = new Book("DDDDD","John",1.0,"Joe","1934834-23823","Phani");
>> em.persist(book);
>>
>>
>> ut.commit();
>>
>> }catch(Exception e){
>> e.printStackTrace();
>> throw new ServletException (e);
>> }
>> ****************************
>>
>> Please note that I am using "RESOURCE_LOCAL" persistence unit. I also
>> used <non-jta-datasource>. I deployed the database pool with
>> </no-transaction> tag in the connector deployment plan.
>>
>> My questions are
>>
>> 1. Should we always use UserTransaction object irrespective of
>> <jta-datasource> or <non-jta-datasource> in JEE environment??
>>
>> 2. How is the use of <non-jta-datsource> different from the use
>> <jta-datasource> in JEE environment??
>>
>> 3. In EJBs, when ContainerManaged Transactions are used, there is no
>> need to use JTA. Is that correct??
>>
>> 4. Only in J2SE environments, we can use EntityTransaction object. is
>> that correct??
>>
>> Thanks in advance.
>> Phani
>>
>> On 5/28/08, David Jencks <da...@yahoo.com> wrote:
>>
>> 1. I hope you named the file openejb-jar.xml
>>
>> 2. jta-datasource and non-jta-datasource have to contain the names of
>>
>> the datasources in the geronimo plan used for the pool, NOT some jndi
>>
>> name you might also map them to. The datasources don't need to be
>>
>> bound in jndi in order to be used for jpa
>>
>> 3. The non-jta-datasource must be a datasource that really has no
>>
>> transaction support, using the <no-transaction/> element instead of
>>
>> <local-transaction/> or <xa-transaction>... in the connector plan.
>>
>> With derby I find it necessary to have a non-jta-datasource if any ddl
>>
>> is needed or if openjpa is generating the primary keys. I don't know
>>
>> if you can get away without one for other databases. If you want to
>>
>> experiment, leave out the non-jta-datasource rather than duplicating
>>
>> the jta-datasource contents.
>>
>>
>> hope this helps
>>
>> david jencks
>>
>>
>> On May 27, 2008, at 4:09 PM, zeros wrote:
>>
>>
>>
>> Good evening:
>>
>>
>> I'm newbie with EJB3.0. I want to configure the persistence.xml
>>
>> to have
>>
>> entities managed with JPA. I have the next configuration files:
>>
>> OPENJPA-JAR.XML
>>
>>
>> <openejb-jar xmlns="http://www.openejb.org/xml/ns/openejb-jar-2.1"
>>
>> xmlns:nam="http://geronimo.apache.org/xml/ns/naming-1.1"
>>
>> xmlns:pkgen="http://www.openejb.org/xml/ns/pkgen-2.0"
>>
>> xmlns:sec="http://geronimo.apache.org/xml/ns/security-1.1"
>>
>> xmlns:sys="http://geronimo.apache.org/xml/ns/deployment-1.2">
>>
>> <sys:environment>
>>
>> <sys:moduleId>
>>
>> <sys:groupId>o2o.marketing</sys:groupId>
>>
>> <sys:artifactId>EJB</sys:artifactId>
>>
>> <sys:version>1.0.8</sys:version>
>>
>> <sys:type>jar</sys:type>
>>
>> </sys:moduleId>
>>
>> <sys:dependencies>
>>
>> <sys:dependency>
>>
>> <sys:groupId>console.dbpool</sys:groupId>
>>
>> <sys:artifactId>marketing</sys:artifactId>
>>
>> <sys:version>1.0</sys:version>
>>
>> <sys:type>rar</sys:type>
>>
>> </sys:dependency>
>>
>> </sys:dependencies>
>>
>> </sys:environment>
>>
>> </openejb-jar>
>>
>>
>> And I have also persistence.xml
>>
>>
>> <?xml version="1.0" encoding="UTF-8"?>
>>
>> <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence
>>
>> "
>>
>> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>>
>> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
>>
>> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
>>
>> <persistence-unit name="marketing">
>>
>> <description>Entity Beans for User</description>
>>
>>
>> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</
>>
>> provider>
>>
>> <jta-data-source>java:comp/env/marketing</jta-data-source>
>>
>> <non-jta-data-source>java:comp/env/marketing</non-jta-data-source>
>>
>> <mapping-file>META-INF/orm.xml</mapping-file>
>>
>> <properties />
>>
>> </persistence-unit>
>>
>> </persistence>
>>
>>
>> The error which I'm having is the next one: Unable to resolve
>>
>> reference
>>
>> "JtaDataSourceWrapper" and Unable to resolve reference
>>
>> "NonJtaDataSourceWrapper", which are basically the same error.
>>
>>
>> I think this is produced because I'm not mapping the Datasocurce to
>>
>> the
>>
>> DBPool. Geronimo returns to me examples to do it for web, but no
>>
>> example to
>>
>> do it for an EJB.
>>
>>
>> Please could you help me?
>>
>>
>> WATCH OUT! I'm talking about entities and EJB3.0, not entiti beans and
>>
>> EJB2.0
>>
>>
>> Thanks in advance
>>
>>
>> SERGIO
>>
>> --
>>
>> View this message in context:
>>
>>
>> http://www.nabble.com/JPA%2C-entities-and-EJB3-tp17502079s134p17502079.html
>>
>> Sent from the Apache Geronimo - Users mailing list archive at
>>
>> Nabble.com.
>>
>>
>>
>>
>>
>>
>
Re: JPA, entities and EJB3
Posted by Phani Madgula <ph...@gmail.com>.
Thanks for the info. I looked into Spec and got a very vague idea of what's
happening here. Let me test these scenarios with some samples and understand
what's happening.
Thanks
Phani
On Mon, Jun 9, 2008 at 11:35 PM, David Jencks <da...@yahoo.com>
wrote:
> I looked in the spec a bit and am not sure I understand how all the parts
> are meshing, maybe david blevins can chime in... I think that you've
> specified contradictory information and maybe we should be complaining
> rather than supplying a container managed jta EntityManager.
> I _think_ that your annotation-injected EntityManager has to be container
> managed and hence jta.
> I _think_ that if you want a resource-local EntityManager you have to
> inject the EMF with a PersistenceUnit annotation and get the EntityManager
> yourself.
>
> In the spec, section 5.6 starts:
> Whenacontainer-managedentitymanager isused, thelifecycleof
> thepersistencecontext isalways
> managedautomatically, transparentlytotheapplication,
> andthepersistencecontextispropagatedwith
> the JTA transaction.
>
>
> I think this means that with your @PersistenceContext annotation, you are
> definitely going to get a tx-type=JTA EM. Since you specified
> RESOURCE_LOCAL in the persistence.xml I think we should perhaps be
> objecting.
>
> I also think this means that you need an application managed persistence
> context to get RESOURCE_LOCAL. There are a bunch of examples in section 5.7
> that all use @PersistenceUnit.
>
> Also hoping for clarification....
> david jencks
>
> On Jun 9, 2008, at 1:43 AM, Phani Madgula wrote:
>
> Hi,
> I have tried to play with <jta-datasource> and <non-jta-datasource> as
> follows.
>
> I have the following peristence.xml in a web application.
> ***********
> <?xml version="1.0" encoding="UTF-8" ?>
> <persistence xmlns="http://java.sun.com/xml/ns/persistence"
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
> version="1.0">
>
> <!-- Tutorial "unit" -->
> <persistence-unit name="Tutorial" transaction-type="RESOURCE_LOCAL">
>
> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
> <non-jta-data-source>ProductDS-nonJTA</non-jta-data-source>
> <mapping-file>orm.xml</mapping-file>
> <class>samples.jpa.Product</class>
> <class>samples.jpa.Book</class>
>
> </persistence-unit>
>
> </persistence>
>
> ***********
>
> In the servlet, I have the following code
>
> ***********
> @PersistenceContext(unitName="Tutorial")
> private EntityManager em;
> .....
> ....
> UserTransaction ut;
> try{
> Context ctx = new InitialContext();
>
> //ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
> //ut.begin();
>
> //EntityTransaction et = em.getTransaction();
> //et.begin();
>
> Book book = new Book("DDDDD","John",1.0,"Joe","1934834-23823","Phani");
> em.persist(book);
>
> //et.commit();
> //ut.commit();
>
> }catch(Exception e){
> e.printStackTrace();
> throw new ServletException (e);
> }
> ***********************
>
> 1. When I hit the servlet, I get the following error.
>
> ***********************
> javax.persistence.TransactionRequiredException : No Active transaction
> ***********************
>
> 2. Suppose I have the following code in the servlet
> **********************
> ***********
> @PersistenceContext(unitName="Tutorial")
> private EntityManager em;
> .....
> ....
> UserTransaction ut;
> try{
> Context ctx = new InitialContext();
>
> //ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
> //ut.begin();
>
> //Uncomment EntityTransaction
> EntityTransaction et = em.getTransaction();
> et.begin();
>
> Book book = new Book("DDDDD","John",1.0,"Joe","1934834-23823","Phani");
> em.persist(book);
>
> et.commit();
> //ut.commit();
>
> }catch(Exception e){
> e.printStackTrace();
> throw new ServletException (e);
> }
> ***********************
> I get the following error
> ***********************
>
> java.lang.IllegalStateException : You can not call getTransaction on
> a container managed EntityManager
>
> *************************
>
> 3. Only if I use JTA API, I am able to get the entity persisted
> properly as below.
> ***************************
> @PersistenceContext(unitName="Tutorial")
> private EntityManager em;
> .....
> ....
> UserTransaction ut;
> try{
> Context ctx = new InitialContext();
>
> ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
> ut.begin();
>
>
> Book book = new Book("DDDDD","John",1.0,"Joe","1934834-23823","Phani");
> em.persist(book);
>
>
> ut.commit();
>
> }catch(Exception e){
> e.printStackTrace();
> throw new ServletException (e);
> }
> ****************************
>
> Please note that I am using "RESOURCE_LOCAL" persistence unit. I also
> used <non-jta-datasource>. I deployed the database pool with
> </no-transaction> tag in the connector deployment plan.
>
> My questions are
>
> 1. Should we always use UserTransaction object irrespective of
> <jta-datasource> or <non-jta-datasource> in JEE environment??
>
> 2. How is the use of <non-jta-datsource> different from the use
> <jta-datasource> in JEE environment??
>
> 3. In EJBs, when ContainerManaged Transactions are used, there is no
> need to use JTA. Is that correct??
>
> 4. Only in J2SE environments, we can use EntityTransaction object. is
> that correct??
>
> Thanks in advance.
> Phani
>
> On 5/28/08, David Jencks <da...@yahoo.com> wrote:
>
> 1. I hope you named the file openejb-jar.xml
>
> 2. jta-datasource and non-jta-datasource have to contain the names of
>
> the datasources in the geronimo plan used for the pool, NOT some jndi
>
> name you might also map them to. The datasources don't need to be
>
> bound in jndi in order to be used for jpa
>
> 3. The non-jta-datasource must be a datasource that really has no
>
> transaction support, using the <no-transaction/> element instead of
>
> <local-transaction/> or <xa-transaction>... in the connector plan.
>
> With derby I find it necessary to have a non-jta-datasource if any ddl
>
> is needed or if openjpa is generating the primary keys. I don't know
>
> if you can get away without one for other databases. If you want to
>
> experiment, leave out the non-jta-datasource rather than duplicating
>
> the jta-datasource contents.
>
>
> hope this helps
>
> david jencks
>
>
> On May 27, 2008, at 4:09 PM, zeros wrote:
>
>
>
> Good evening:
>
>
> I'm newbie with EJB3.0. I want to configure the persistence.xml
>
> to have
>
> entities managed with JPA. I have the next configuration files:
>
> OPENJPA-JAR.XML
>
>
> <openejb-jar xmlns="http://www.openejb.org/xml/ns/openejb-jar-2.1"
>
> xmlns:nam="http://geronimo.apache.org/xml/ns/naming-1.1"
>
> xmlns:pkgen="http://www.openejb.org/xml/ns/pkgen-2.0"
>
> xmlns:sec="http://geronimo.apache.org/xml/ns/security-1.1"
>
> xmlns:sys="http://geronimo.apache.org/xml/ns/deployment-1.2">
>
> <sys:environment>
>
> <sys:moduleId>
>
> <sys:groupId>o2o.marketing</sys:groupId>
>
> <sys:artifactId>EJB</sys:artifactId>
>
> <sys:version>1.0.8</sys:version>
>
> <sys:type>jar</sys:type>
>
> </sys:moduleId>
>
> <sys:dependencies>
>
> <sys:dependency>
>
> <sys:groupId>console.dbpool</sys:groupId>
>
> <sys:artifactId>marketing</sys:artifactId>
>
> <sys:version>1.0</sys:version>
>
> <sys:type>rar</sys:type>
>
> </sys:dependency>
>
> </sys:dependencies>
>
> </sys:environment>
>
> </openejb-jar>
>
>
> And I have also persistence.xml
>
>
> <?xml version="1.0" encoding="UTF-8"?>
>
> <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence
>
> "
>
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>
> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
>
> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
>
> <persistence-unit name="marketing">
>
> <description>Entity Beans for User</description>
>
>
> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</
>
> provider>
>
> <jta-data-source>java:comp/env/marketing</jta-data-source>
>
> <non-jta-data-source>java:comp/env/marketing</non-jta-data-source>
>
> <mapping-file>META-INF/orm.xml</mapping-file>
>
> <properties />
>
> </persistence-unit>
>
> </persistence>
>
>
> The error which I'm having is the next one: Unable to resolve
>
> reference
>
> "JtaDataSourceWrapper" and Unable to resolve reference
>
> "NonJtaDataSourceWrapper", which are basically the same error.
>
>
> I think this is produced because I'm not mapping the Datasocurce to
>
> the
>
> DBPool. Geronimo returns to me examples to do it for web, but no
>
> example to
>
> do it for an EJB.
>
>
> Please could you help me?
>
>
> WATCH OUT! I'm talking about entities and EJB3.0, not entiti beans and
>
> EJB2.0
>
>
> Thanks in advance
>
>
> SERGIO
>
> --
>
> View this message in context:
>
> http://www.nabble.com/JPA%2C-entities-and-EJB3-tp17502079s134p17502079.html
>
> Sent from the Apache Geronimo - Users mailing list archive at
>
> Nabble.com.
>
>
>
>
>
>
Re: JPA, entities and EJB3
Posted by David Jencks <da...@yahoo.com>.
I looked in the spec a bit and am not sure I understand how all the
parts are meshing, maybe david blevins can chime in... I think that
you've specified contradictory information and maybe we should be
complaining rather than supplying a container managed jta EntityManager.
I _think_ that your annotation-injected EntityManager has to be
container managed and hence jta.
I _think_ that if you want a resource-local EntityManager you have to
inject the EMF with a PersistenceUnit annotation and get the
EntityManager yourself.
In the spec, section 5.6 starts:
Whenacontainer-managedentitymanager isused, thelifecycleof
thepersistencecontext isalways
managedautomatically, transparentlytotheapplication,
andthepersistencecontextispropagatedwith
the JTA transaction.
I think this means that with your @PersistenceContext annotation, you
are definitely going to get a tx-type=JTA EM. Since you specified
RESOURCE_LOCAL in the persistence.xml I think we should perhaps be
objecting.
I also think this means that you need an application managed
persistence context to get RESOURCE_LOCAL. There are a bunch of
examples in section 5.7 that all use @PersistenceUnit.
Also hoping for clarification....
david jencks
On Jun 9, 2008, at 1:43 AM, Phani Madgula wrote:
> Hi,
> I have tried to play with <jta-datasource> and <non-jta-datasource>
> as follows.
>
> I have the following peristence.xml in a web application.
> ***********
> <?xml version="1.0" encoding="UTF-8" ?>
> <persistence xmlns="http://java.sun.com/xml/ns/persistence"
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
> version="1.0">
>
> <!-- Tutorial "unit" -->
> <persistence-unit name="Tutorial" transaction-
> type="RESOURCE_LOCAL">
> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</
> provider>
> <non-jta-data-source>ProductDS-nonJTA</non-jta-data-source>
> <mapping-file>orm.xml</mapping-file>
> <class>samples.jpa.Product</class>
> <class>samples.jpa.Book</class>
>
> </persistence-unit>
>
> </persistence>
>
> ***********
>
> In the servlet, I have the following code
>
> ***********
> @PersistenceContext(unitName="Tutorial")
> private EntityManager em;
> .....
> ....
> UserTransaction ut;
> try{
> Context ctx = new InitialContext();
>
> //ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
> //ut.begin();
>
> //EntityTransaction et = em.getTransaction();
> //et.begin();
>
> Book book = new Book("DDDDD","John",
> 1.0,"Joe","1934834-23823","Phani");
> em.persist(book);
>
> //et.commit();
> //ut.commit();
>
> }catch(Exception e){
> e.printStackTrace();
> throw new ServletException (e);
> }
> ***********************
>
> 1. When I hit the servlet, I get the following error.
>
> ***********************
> javax.persistence.TransactionRequiredException : No Active
> transaction
> ***********************
>
> 2. Suppose I have the following code in the servlet
> **********************
> ***********
> @PersistenceContext(unitName="Tutorial")
> private EntityManager em;
> .....
> ....
> UserTransaction ut;
> try{
> Context ctx = new InitialContext();
>
> //ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
> //ut.begin();
>
> //Uncomment EntityTransaction
> EntityTransaction et = em.getTransaction();
> et.begin();
>
> Book book = new Book("DDDDD","John",
> 1.0,"Joe","1934834-23823","Phani");
> em.persist(book);
>
> et.commit();
> //ut.commit();
>
> }catch(Exception e){
> e.printStackTrace();
> throw new ServletException (e);
> }
> ***********************
> I get the following error
> ***********************
>
> java.lang.IllegalStateException : You can not call getTransaction on
> a container managed EntityManager
>
> *************************
>
> 3. Only if I use JTA API, I am able to get the entity persisted
> properly as below.
> ***************************
> @PersistenceContext(unitName="Tutorial")
> private EntityManager em;
> .....
> ....
> UserTransaction ut;
> try{
> Context ctx = new InitialContext();
>
> ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
> ut.begin();
>
>
> Book book = new Book("DDDDD","John",
> 1.0,"Joe","1934834-23823","Phani");
> em.persist(book);
>
>
> ut.commit();
>
> }catch(Exception e){
> e.printStackTrace();
> throw new ServletException (e);
> }
> ****************************
>
> Please note that I am using "RESOURCE_LOCAL" persistence unit. I also
> used <non-jta-datasource>. I deployed the database pool with
> </no-transaction> tag in the connector deployment plan.
>
> My questions are
>
> 1. Should we always use UserTransaction object irrespective of
> <jta-datasource> or <non-jta-datasource> in JEE environment??
>
> 2. How is the use of <non-jta-datsource> different from the use
> <jta-datasource> in JEE environment??
>
> 3. In EJBs, when ContainerManaged Transactions are used, there is no
> need to use JTA. Is that correct??
>
> 4. Only in J2SE environments, we can use EntityTransaction object. is
> that correct??
>
> Thanks in advance.
> Phani
>
> On 5/28/08, David Jencks <da...@yahoo.com> wrote:
>> 1. I hope you named the file openejb-jar.xml
>> 2. jta-datasource and non-jta-datasource have to contain the names of
>> the datasources in the geronimo plan used for the pool, NOT some jndi
>> name you might also map them to. The datasources don't need to be
>> bound in jndi in order to be used for jpa
>> 3. The non-jta-datasource must be a datasource that really has no
>> transaction support, using the <no-transaction/> element instead of
>> <local-transaction/> or <xa-transaction>... in the connector plan.
>> With derby I find it necessary to have a non-jta-datasource if any
>> ddl
>> is needed or if openjpa is generating the primary keys. I don't know
>> if you can get away without one for other databases. If you want to
>> experiment, leave out the non-jta-datasource rather than duplicating
>> the jta-datasource contents.
>>
>> hope this helps
>> david jencks
>>
>> On May 27, 2008, at 4:09 PM, zeros wrote:
>>
>>>
>>> Good evening:
>>>
>>> I'm newbie with EJB3.0. I want to configure the persistence.xml
>>> to have
>>> entities managed with JPA. I have the next configuration files:
>>> OPENJPA-JAR.XML
>>>
>>> <openejb-jar xmlns="http://www.openejb.org/xml/ns/openejb-jar-2.1"
>>> xmlns:nam="http://geronimo.apache.org/xml/ns/naming-1.1"
>>> xmlns:pkgen="http://www.openejb.org/xml/ns/pkgen-2.0"
>>> xmlns:sec="http://geronimo.apache.org/xml/ns/security-1.1"
>>> xmlns:sys="http://geronimo.apache.org/xml/ns/deployment-1.2">
>>> <sys:environment>
>>> <sys:moduleId>
>>> <sys:groupId>o2o.marketing</sys:groupId>
>>> <sys:artifactId>EJB</sys:artifactId>
>>> <sys:version>1.0.8</sys:version>
>>> <sys:type>jar</sys:type>
>>> </sys:moduleId>
>>> <sys:dependencies>
>>> <sys:dependency>
>>> <sys:groupId>console.dbpool</sys:groupId>
>>> <sys:artifactId>marketing</sys:artifactId>
>>> <sys:version>1.0</sys:version>
>>> <sys:type>rar</sys:type>
>>> </sys:dependency>
>>> </sys:dependencies>
>>> </sys:environment>
>>> </openejb-jar>
>>>
>>> And I have also persistence.xml
>>>
>>> <?xml version="1.0" encoding="UTF-8"?>
>>> <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence
>>> "
>>> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>>> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
>>> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
>>> <persistence-unit name="marketing">
>>> <description>Entity Beans for User</description>
>>>
>>> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</
>>> provider>
>>> <jta-data-source>java:comp/env/marketing</jta-data-source>
>>> <non-jta-data-source>java:comp/env/marketing</non-jta-data-
>>> source>
>>> <mapping-file>META-INF/orm.xml</mapping-file>
>>> <properties />
>>> </persistence-unit>
>>> </persistence>
>>>
>>> The error which I'm having is the next one: Unable to resolve
>>> reference
>>> "JtaDataSourceWrapper" and Unable to resolve reference
>>> "NonJtaDataSourceWrapper", which are basically the same error.
>>>
>>> I think this is produced because I'm not mapping the Datasocurce to
>>> the
>>> DBPool. Geronimo returns to me examples to do it for web, but no
>>> example to
>>> do it for an EJB.
>>>
>>> Please could you help me?
>>>
>>> WATCH OUT! I'm talking about entities and EJB3.0, not entiti beans
>>> and
>>> EJB2.0
>>>
>>> Thanks in advance
>>>
>>> SERGIO
>>> --
>>> View this message in context:
>>> http://www.nabble.com/JPA%2C-entities-and-EJB3-tp17502079s134p17502079.html
>>> Sent from the Apache Geronimo - Users mailing list archive at
>>> Nabble.com.
>>>
>>
>>
Re: JPA, entities and EJB3
Posted by Phani Madgula <ph...@gmail.com>.
Hi,
I have tried to play with <jta-datasource> and <non-jta-datasource> as follows.
I have the following peristence.xml in a web application.
***********
<?xml version="1.0" encoding="UTF-8" ?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
version="1.0">
<!-- Tutorial "unit" -->
<persistence-unit name="Tutorial" transaction-type="RESOURCE_LOCAL">
<provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
<non-jta-data-source>ProductDS-nonJTA</non-jta-data-source>
<mapping-file>orm.xml</mapping-file>
<class>samples.jpa.Product</class>
<class>samples.jpa.Book</class>
</persistence-unit>
</persistence>
***********
In the servlet, I have the following code
***********
@PersistenceContext(unitName="Tutorial")
private EntityManager em;
.....
....
UserTransaction ut;
try{
Context ctx = new InitialContext();
//ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
//ut.begin();
//EntityTransaction et = em.getTransaction();
//et.begin();
Book book = new Book("DDDDD","John",1.0,"Joe","1934834-23823","Phani");
em.persist(book);
//et.commit();
//ut.commit();
}catch(Exception e){
e.printStackTrace();
throw new ServletException (e);
}
***********************
1. When I hit the servlet, I get the following error.
***********************
javax.persistence.TransactionRequiredException : No Active transaction
***********************
2. Suppose I have the following code in the servlet
**********************
***********
@PersistenceContext(unitName="Tutorial")
private EntityManager em;
.....
....
UserTransaction ut;
try{
Context ctx = new InitialContext();
//ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
//ut.begin();
//Uncomment EntityTransaction
EntityTransaction et = em.getTransaction();
et.begin();
Book book = new Book("DDDDD","John",1.0,"Joe","1934834-23823","Phani");
em.persist(book);
et.commit();
//ut.commit();
}catch(Exception e){
e.printStackTrace();
throw new ServletException (e);
}
***********************
I get the following error
***********************
java.lang.IllegalStateException : You can not call getTransaction on
a container managed EntityManager
*************************
3. Only if I use JTA API, I am able to get the entity persisted
properly as below.
***************************
@PersistenceContext(unitName="Tutorial")
private EntityManager em;
.....
....
UserTransaction ut;
try{
Context ctx = new InitialContext();
ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
ut.begin();
Book book = new Book("DDDDD","John",1.0,"Joe","1934834-23823","Phani");
em.persist(book);
ut.commit();
}catch(Exception e){
e.printStackTrace();
throw new ServletException (e);
}
****************************
Please note that I am using "RESOURCE_LOCAL" persistence unit. I also
used <non-jta-datasource>. I deployed the database pool with
</no-transaction> tag in the connector deployment plan.
My questions are
1. Should we always use UserTransaction object irrespective of
<jta-datasource> or <non-jta-datasource> in JEE environment??
2. How is the use of <non-jta-datsource> different from the use
<jta-datasource> in JEE environment??
3. In EJBs, when ContainerManaged Transactions are used, there is no
need to use JTA. Is that correct??
4. Only in J2SE environments, we can use EntityTransaction object. is
that correct??
Thanks in advance.
Phani
On 5/28/08, David Jencks <da...@yahoo.com> wrote:
> 1. I hope you named the file openejb-jar.xml
> 2. jta-datasource and non-jta-datasource have to contain the names of
> the datasources in the geronimo plan used for the pool, NOT some jndi
> name you might also map them to. The datasources don't need to be
> bound in jndi in order to be used for jpa
> 3. The non-jta-datasource must be a datasource that really has no
> transaction support, using the <no-transaction/> element instead of
> <local-transaction/> or <xa-transaction>... in the connector plan.
> With derby I find it necessary to have a non-jta-datasource if any ddl
> is needed or if openjpa is generating the primary keys. I don't know
> if you can get away without one for other databases. If you want to
> experiment, leave out the non-jta-datasource rather than duplicating
> the jta-datasource contents.
>
> hope this helps
> david jencks
>
> On May 27, 2008, at 4:09 PM, zeros wrote:
>
>>
>> Good evening:
>>
>> I'm newbie with EJB3.0. I want to configure the persistence.xml
>> to have
>> entities managed with JPA. I have the next configuration files:
>> OPENJPA-JAR.XML
>>
>> <openejb-jar xmlns="http://www.openejb.org/xml/ns/openejb-jar-2.1"
>> xmlns:nam="http://geronimo.apache.org/xml/ns/naming-1.1"
>> xmlns:pkgen="http://www.openejb.org/xml/ns/pkgen-2.0"
>> xmlns:sec="http://geronimo.apache.org/xml/ns/security-1.1"
>> xmlns:sys="http://geronimo.apache.org/xml/ns/deployment-1.2">
>> <sys:environment>
>> <sys:moduleId>
>> <sys:groupId>o2o.marketing</sys:groupId>
>> <sys:artifactId>EJB</sys:artifactId>
>> <sys:version>1.0.8</sys:version>
>> <sys:type>jar</sys:type>
>> </sys:moduleId>
>> <sys:dependencies>
>> <sys:dependency>
>> <sys:groupId>console.dbpool</sys:groupId>
>> <sys:artifactId>marketing</sys:artifactId>
>> <sys:version>1.0</sys:version>
>> <sys:type>rar</sys:type>
>> </sys:dependency>
>> </sys:dependencies>
>> </sys:environment>
>> </openejb-jar>
>>
>> And I have also persistence.xml
>>
>> <?xml version="1.0" encoding="UTF-8"?>
>> <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence
>> "
>> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
>> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
>> <persistence-unit name="marketing">
>> <description>Entity Beans for User</description>
>>
>> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</
>> provider>
>> <jta-data-source>java:comp/env/marketing</jta-data-source>
>> <non-jta-data-source>java:comp/env/marketing</non-jta-data-source>
>> <mapping-file>META-INF/orm.xml</mapping-file>
>> <properties />
>> </persistence-unit>
>> </persistence>
>>
>> The error which I'm having is the next one: Unable to resolve
>> reference
>> "JtaDataSourceWrapper" and Unable to resolve reference
>> "NonJtaDataSourceWrapper", which are basically the same error.
>>
>> I think this is produced because I'm not mapping the Datasocurce to
>> the
>> DBPool. Geronimo returns to me examples to do it for web, but no
>> example to
>> do it for an EJB.
>>
>> Please could you help me?
>>
>> WATCH OUT! I'm talking about entities and EJB3.0, not entiti beans and
>> EJB2.0
>>
>> Thanks in advance
>>
>> SERGIO
>> --
>> View this message in context:
>> http://www.nabble.com/JPA%2C-entities-and-EJB3-tp17502079s134p17502079.html
>> Sent from the Apache Geronimo - Users mailing list archive at
>> Nabble.com.
>>
>
>
Re: JPA, entities and EJB3
Posted by David Jencks <da...@yahoo.com>.
1. I hope you named the file openejb-jar.xml
2. jta-datasource and non-jta-datasource have to contain the names of
the datasources in the geronimo plan used for the pool, NOT some jndi
name you might also map them to. The datasources don't need to be
bound in jndi in order to be used for jpa
3. The non-jta-datasource must be a datasource that really has no
transaction support, using the <no-transaction/> element instead of
<local-transaction/> or <xa-transaction>... in the connector plan.
With derby I find it necessary to have a non-jta-datasource if any ddl
is needed or if openjpa is generating the primary keys. I don't know
if you can get away without one for other databases. If you want to
experiment, leave out the non-jta-datasource rather than duplicating
the jta-datasource contents.
hope this helps
david jencks
On May 27, 2008, at 4:09 PM, zeros wrote:
>
> Good evening:
>
> I'm newbie with EJB3.0. I want to configure the persistence.xml
> to have
> entities managed with JPA. I have the next configuration files:
> OPENJPA-JAR.XML
>
> <openejb-jar xmlns="http://www.openejb.org/xml/ns/openejb-jar-2.1"
> xmlns:nam="http://geronimo.apache.org/xml/ns/naming-1.1"
> xmlns:pkgen="http://www.openejb.org/xml/ns/pkgen-2.0"
> xmlns:sec="http://geronimo.apache.org/xml/ns/security-1.1"
> xmlns:sys="http://geronimo.apache.org/xml/ns/deployment-1.2">
> <sys:environment>
> <sys:moduleId>
> <sys:groupId>o2o.marketing</sys:groupId>
> <sys:artifactId>EJB</sys:artifactId>
> <sys:version>1.0.8</sys:version>
> <sys:type>jar</sys:type>
> </sys:moduleId>
> <sys:dependencies>
> <sys:dependency>
> <sys:groupId>console.dbpool</sys:groupId>
> <sys:artifactId>marketing</sys:artifactId>
> <sys:version>1.0</sys:version>
> <sys:type>rar</sys:type>
> </sys:dependency>
> </sys:dependencies>
> </sys:environment>
> </openejb-jar>
>
> And I have also persistence.xml
>
> <?xml version="1.0" encoding="UTF-8"?>
> <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence
> "
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
> xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
> http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
> <persistence-unit name="marketing">
> <description>Entity Beans for User</description>
>
> <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</
> provider>
> <jta-data-source>java:comp/env/marketing</jta-data-source>
> <non-jta-data-source>java:comp/env/marketing</non-jta-data-source>
> <mapping-file>META-INF/orm.xml</mapping-file>
> <properties />
> </persistence-unit>
> </persistence>
>
> The error which I'm having is the next one: Unable to resolve
> reference
> "JtaDataSourceWrapper" and Unable to resolve reference
> "NonJtaDataSourceWrapper", which are basically the same error.
>
> I think this is produced because I'm not mapping the Datasocurce to
> the
> DBPool. Geronimo returns to me examples to do it for web, but no
> example to
> do it for an EJB.
>
> Please could you help me?
>
> WATCH OUT! I'm talking about entities and EJB3.0, not entiti beans and
> EJB2.0
>
> Thanks in advance
>
> SERGIO
> --
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> Nabble.com.
>