We created some libraries that all our projects will use, this libraries will provide the basic functionality of all our systems (login, some manage, etc). But the application itself could use another database.
What we did was to create the Persistence.xml with two persist units. And package all the core library entities in a jar called "LN-model.jar" and all of the entities of out test app in "App-model.jar". But for some reason we still obtain the following message.
Could not resolve a persistence unit corresponding to the persistence-context-ref-name [x.x.x.x.listener.InicializadorListener/em] in the scope of the module called [gfdeploy#/Users/zkropotkine/WORK/SeguridadCore/dist/gfdeploy/SeguridadCore-war_war]. Please verify your application.
Here's our Persistence.xml
<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="x" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<jta-data-source>jdbc/x</jta-data-source>
<jar-file>App-model.jar</jar-file>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
</properties>
</persistence-unit>
<persistence-unit name="y" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<jta-data-source>jdbc/y</jta-data-source>
<jar-file>LN-model.jar</jar-file>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties/>
</persistence-unit>
By the way we put the Persistence.xml in a jar, that we add to our Enterprise Project (EAR).
The problem is that the JPA does not know which is the persistence unit to use. when you have only one persistence unit this problem does not occur. To fix do the following:
You need to specify a persistence unit : #PersistenceContext(unitName="...") in the Ejb that do not have
You can add the annotations:
#PersistenceUnit(name = "x")
EntityManagerFactory entityManagerFactory;
#PersistenceContext(unitName = "y")
EntityManager entityManager;
Or you can create it manually:
EntityManagerFactory emfA = Persistence.createEntityManagerFactory("x", properties);
EntityManagerFactory emfB = Persistence.createEntityManagerFactory("y", properties);
For more details, please see the following link: https://docs.oracle.com/html/E25034_01/usingmultipledbs.htm
is very useful, to me helped me!
Related
I am getting the following error when I am using Jboss 4.2.3 GA and configured my ms-sql.ds file. I created an Entity Bean EJB3 and I am trying to access that Entity bean from EJB 2.1 Session Bean. First of all, I wanted to check if it is possible. Because when I use EntityManager or EntityManagerFactory,
my EntityManager is comming as null. Also instead if I use EntityManagerFactory, it gives
an error saying:
javax.persistence.PersistenceException: No Persistence provider for
EntityManager named EjbComponentPU
Below is my class
public class TestBean implements SessionBean {
//pass persistence unit to entityManager.
#PersistenceContext(unitName="EjbComponentPU")
private EntityManager entitymanager;
My Project folder structure is:
src - has the all the packages.
Inside that I have META-INF folder which has the persistence.xml file
Thanks for any help.
this is my persistence.xml file.
<?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="EjbComponentPU" transaction-type="JTA">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<jta-data-source>java:/testDS</jta-data-source>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
</persistence-unit>
I need two or more than two connections in my web application using jpa
To use different data sources, add multiple persistence units (say, source-1 and source-2 in persistence.xml and create multiple EntityManagerFactoryes by name):
EntityManagerFactory emf1 = Persistence.createEntityManagerFactory("source-1");
EntityManagerFactory emf2 = Persistence.createEntityManagerFactory("source-2");
or, if you're working on Spring or Java EE application server, inject them by name also:
#PersistenceUnit(name = "source-1")
EntityManagerFactory emf1;
#PersistenceContext(unitName = "source-2") // as an option
EntityManager em2;
persistence.xml will thus look like the following:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="source-1" transaction-type="RESOURCE_LOCAL">
<properties>
<!-- source-1 properties here -->
</properties>
</persistence-unit>
<persistence-unit name="source-2" transaction-type="RESOURCE_LOCAL">
<properties>
<!-- source-2 properties here -->
</properties>
</persistence-unit>
</persistence>
Example of how to configure persistence unit, create EntityManager to manage entities and execute queries can be found here.
For single datasource jpa will use multiple connections internally.So you don't need to do anything.
I'm trying to use DRY in my persistence.xml file in different persistence units.
I have the following persistence.xml (it's just one file):
<persistence-unit name="siteAPU" transaction-type="JTA">
<jta-data-source>java:/siteADS</jta-data-source>
<class>package.name.Subs</class>
<class>package.name.SubsRef</class>
<class>package.name.SubsLoc</class>
...
<persistence-unit name="siteBPU" transaction-type="JTA">
<jta-data-source>java:/siteBDS</jta-data-source>
<class>package.name.Subs</class>
<class>package.name.SubsRef</class>
<class>package.name.SubsLoc</class>
...
You can see I have two different persistence units and I have the same classes being persisted.
Is there a way I can programmatically generate the persistence.xml file and don't repeat the content inside each persistence unit?
create a orm file:
<persistence-unit name="YOU_PU" ...>
<provider>YOU_PROVIDER</provider>
<mapping-file>orm.xml</mapping-file>
Inside the ORM file you will write the entities.
There is a sample here: https://github.com/uaihebert/uaicriteria/blob/master/src/test/resources/orm.xml
I have created a Hibernate / JPA project and I'd like to create entities from tables.
While the tool works like a charm selecting a pure Hibernate configuration, in the JPA mode it does not work, claiming the absence of the persistence unit
As shown in the following photo, the persistence unit is located in the folder /src/main/resources/META-INF
This is the code of persistence.xml file:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" 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_2_0.xsd">
<persistence-unit name="socialsports" transaction-type="JTA">
<provider>org.hibernate.ejb.HibernatePersistenceProvider</provider>
<jta-data-source>jdbc/LiveDataSource</jta-data-source>
</persistence-unit>
</persistence>
This is the result of my attempt to run Hibernate tools to generate entities:
Since it only doesn't work in JPA mode, the use of the deprecated org.hibernate.ejb.HibernatePersistenceProvider could be a problem. Try org.hibernate.jpa.HibernatePersistenceProvider instead.
I'm getting the error "Class "test2" is mapped, but is not included in any" in eclipse, however the class is included in persistence xml.
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0"
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_2_0.xsd">
<persistence-unit name="test1">
<class>com.test.domains.test1</class>
<properties>
<!-- properties for schema1 here -->
</properties>
</persistence-unit>
<persistence-unit name="test2">
<class>com.test.test2</class>
<properties>
<!-- properties for schema 2 here -->
</properties>
</persistence-unit>
</persistence>
Why does this error appear. Do I have to configure it different for 2 db schemas?
Eclipse (or more specifically Dali) do have limitation, it does not support two persistence units. That is also told in their pages:
Currently Dali only supports one Persistence Unit and one Persistence
XML file per project. Other configurations can exist in a JPA project,
but the validation and defaults processing may not be correct when
multiple persistence units are used.
What it comes to JPA itself, persistence.xml seems to becorrect. There is no need to add same class to two persistence units.