此持久性单元配置有什么问题？

Question

I am trying to set up a persistence unit in JEE 6 on JBoss AS 6.

The injected EntityManager is always null. I've fiddled around with the configuration quite a bit but can't get anything to work. I've tried JTA/LOCAL_RESOURCE, I've tried using a unit name in my code the same as in my persistence.xml, but also with the war name prepended, as the log suggests the JNDI name might be that.

I have a mysql-ds.xml file as follows:

<?xml version="1.0" encoding="UTF-8"?>
<datasources>
  <local-tx-datasource>

    <jndi-name>myconnection</jndi-name>
    <connection-url>jdbc:mysql://localhost:3306/cog1</connection-url>
    <driver-class>org.gjt.mm.mysql.Driver</driver-class>
    <user-name>bw</user-name>
    <password></password>

    <min-pool-size>2</min-pool-size>
    <max-pool-size>20</max-pool-size>
    <idle-timeout-minutes>5</idle-timeout-minutes>

    <exception-sorter-class-name>com.mysql.jdbc.integration.jboss.ExtendedMysqlExceptionSorter</exception-sorter-class-name>
    <valid-connection-checker-class-name>com.mysql.jdbc.integration.jboss.MysqlValidConnectionChecker</valid-connection-checker-class-name>

  </local-tx-datasource>
</datasources>

I have a persistence.xml as follows:

<?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_2_0.xsd"
    version="2.0">
    <persistence-unit name="myunit" transaction-type="RESOURCE_LOCAL">
            <jta-data-source>java:/myconnection</jta-data-source>
            <non-jta-data-source>java:/myconnection</non-jta-data-source>
            <class>com.cognitura.simulation.dao.model.History</class>
            <properties>
                    <property name="eclipselink.ddl-generation" value="drop-and-create-tables" />
                    <property name="eclipselink.logging.level" value="INFO" />
            </properties>
    </persistence-unit>
</persistence>

And I have a bean with the following code in it:

@Stateful
@LocalBean
public class HistoryEJB {

    @PersistenceContext(unitName = "myunit")
    private EntityManager em;

    @EJB
    private RealityElement el;

I can see that the RealityElement el is getting injected fine, so I think it's definitely being container-managed?

Grateful for any ideas!

EDIT: The logs seem to be fine for setting up the 'myunit' unit. There is a warning, but I read that it's not important?

01:28:06,276 INFO  [org.jboss.jpa.deployment.PersistenceUnitDeployment] Starting persistence unit persistence.unit:unitN
ame=cog1.war#myunit
01:28:06,278 INFO  [org.hibernate.ejb.Ejb3Configuration] Processing PersistenceUnitInfo [
    name: myunit
    ...]
01:28:06,305 WARN  [org.hibernate.ejb.Ejb3Configuration] Persistence provider caller does not implement the EJB3 spec co
rrectly.PersistenceUnitInfo.getNewTempClassLoader() is null.

Seems happy here:

01:28:06,965 INFO  [org.hibernate.impl.SessionFactoryObjectFactory] Bound factory to JNDI name: persistence.unit:unitNam
e=cog1.war#myunit

Answer 1

Could it be the jndi name? Try making the following changes in datasource and persistence files

<jndi-name>java:jboss/datasources/employeedb</jndi-name>

<jta-data-source>java:jboss/datasources/employeedb</jta-data-source>