transactions and distributed transactions in ejb3

[grdzeli_kaci]

fierst of all sorry for my english :)
1.I've jboss-4.0.4.GA configured with EJB3 and it was working fine before i deside working with transaction. :)
i have one entity bean (for example Student) and one stateless session bean like this :

TransactionManagement(value = TransactionManagementType.BEAN)
@Remote(StudentFasade.class)
public @Stateless
class StudentFasadeBean implements StudentFasade {
 @PersistenceContext
 private EntityManager manager;
 @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
 public Long addStudent(Student stbean)
 throws MagtiException {
 try {
 manager.getTransaction().begin();
 manager.persist(_student);
 manager.getTransaction().commit();
 return _student.getId();
 } catch (Exception e) {
 manager.getTransaction().rollback();
 }
 }
}

and this is my persistance.xml file :

<?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">
 <persistence-unit name="Students Registration" transaction-type="JTA">
 <jta-data-source>java:/XAOracleDS</jta-data-source>
 <class>com.magti.businesslayer.ejb3entity.Student</class>
 <properties>
 <property name="hibernate.dialect" value="org.hibernate.dialect.OracleDialect"/>
 <property name="hibernate.connection.driver_class" value="oracle.jdbc.driver.OracleDriver"/>
 <property name="hibernate.connection.url" value="jdbc:oracle:thin:@192.9.200.177:1521:devnbtwo"/>
 <property name="hibernate.connection.username" value="paata"/>
 <property name="hibernate.connection.password" value="1982226"/>
 <property name="hibernate.default_schema" value="PAATA"/>
 </properties>
 </persistence-unit>
</persistence>

and in client side i get error like this:

Exception in thread "main" java.lang.IllegalStateException: Illegal to call this method from injected, managed EntityManager
 at org.jboss.ejb3.entity.TransactionScopedEntityManager.getTransaction(TransactionScopedEntityManager.java:219)

and one other question :) how i can workig with distributed transactions in ejb3 (i mean that bean insert two different database and i want manage both transaction of them)

thanks .....

[weston.price]

Hi, your English is just fine!

The issue is you are trying to acquire a transaction in a component that manages transactions for you.

Remove the

manager.getTransaction().begin();
manager.getTransaction().commit();

and the associated rollback.

For the distributed (multi DB) transaction you just need two XA datasources. Please see

http://wiki.jboss.org/wiki/Wiki.jsp?page=JBossJCA

to learn how to set up XA datasources.

[grdzeli_kaci]

thanks ...
i will try it .

[grdzeli_kaci]

[e-mail]

did u mean "JBoss Transactions API" named ArjunaTA ?


i removed this code from my program

manager.getTransaction().begin();
manager.getTransaction().commit();
manager.getTransaction().rollback();

but i get en error again :(
error

javax.persistence.TransactionRequiredException: EntityManager must be access within a transaction
23:19:47,281 ERROR [STDERR] at org.jboss.ejb3.entity.ManagedEntityManagerFactory.verifyInTx(ManagedEntityManagerFactory.java:149)
23:19:47,281 ERROR [STDERR] at org.jboss.ejb3.entity.TransactionScopedEntityManager.persist(TransactionScopedEntityManager.java:174)

my bean looks like :

import [...]
@TransactionManagement(value = TransactionManagementType.BEAN)
@Remote(StudentFasade.class)
public @Stateless
class StudentFasadeBean implements StudentFasade {

 @PersistenceContext
 private EntityManager manager;

 @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
 public Long addStudent(Student stbean)
 throws MagtiException {
 try {
 System.out.println("================= Adding Student =====================");
 manager.persist(stbean);
 return _student.getId();

 } catch (Exception e) {
 e.printStackTrace();
 return 0L;
 }
 }
}

[epbernard]

remove @TransactionManagement(value = TransactionManagementType.BEAN)

in most case you don't want to handle tx management yourself

[grdzeli_kaci]

ok thanks u're rigth .... it works.... but
what can i do when i wont work with multiple database ?
i think that i need to xml datasourse file (for example : oracle-xa-ds.xml and postgres-ds.xml) both of them configured corectly :
oracle ds file :

<datasources>
 <xa-datasource>
 <jndi-name>XAOracleDS</jndi-name>
 <track-connection-by-tx/>
 <isSameRM-override-value>false</isSameRM-override-value> <xa-datasource-class>oracle.jdbc.xa.client.OracleXADataSource</xa-datasource-class>
 <xa-datasource-property name="URL">jdbc:oracle:thin:@192.9.200.177:1521:devnbtwo</xa-datasource-property>
 <xa-datasource-property name="User">paata</xa-datasource-property>
 <xa-datasource-property name="Password">1982226</xa-datasource-property> <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.OracleExceptionSorter</exception-sorter-class-name>
 <no-tx-separate-pools/>
 <metadata>
 <type-mapping>Oracle9i</type-mapping>
 </metadata>
 </xa-datasource>
 <mbean code="org.jboss.resource.adapter.jdbc.vendor.OracleXAExceptionFormatter"
 name="jboss.jca:service=OracleXAExceptionFormatter">
 <depends optional-attribute-name="TransactionManagerService">jboss:service=TransactionManager</depends>
 </mbean>
</datasources>

and postgres ds file:

<datasources>
 <local-tx-datasource>
 <jndi-name>PostgresDS</jndi-name>
 <connection-url>jdbc:postgresql://localhost:5432/Test</connection-url>
 <driver-class>org.postgresql.Driver</driver-class>
 <user-name>postgres</user-name>
 <password>1982226</password>
 <new-connection-sql>select 1</new-connection-sql>
 <metadata>
 <type-mapping>PostgreSQL 7.2</type-mapping>
 </metadata>
 </local-tx-datasource>
</datasources>

and i want do operation wich inserts into one db and then into second db in one transaction ....
how i can do it ? :( plz F1 :)

[e-mail] told me about JBossJCA
but i didn't find any sample about it ...
is there any simple example about distributed transactions ...

[grdzeli_kaci]

i can't resolve this problem again ...
could anybody help me ?