Consegui resolver o problema.
Eu estava criando o Persistence.xml pelo netbeans usando o EclipseLink e não estava funcionando.Depois gerei o Persistence.xml de novo pelo netbeans só que dessa vez usando o TopLink e funcionou.
O netbeans para o Eclipeplink criou o arquivo começando com “<persistence version=“2.0”…” e para o TopLink criou “<persistence version=“1.0”…”.
Com TopLink funciona e com o EclipseLink não.O que eu não entendi agora é que se eu chegar no arquivo persistence.xml do EclipseLink e alterar “<persistence version=“2.0”…” para “<persistence version=“1.0”…” ele funciona.
Alguém sabe me explicar porque isso acontece?
Persistence.xml gerado pelo Netbeans para o TopLink:
<?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="SePlagPU" transaction-type="RESOURCE_LOCAL">
<provider>oracle.toplink.essentials.PersistenceProvider</provider>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="toplink.jdbc.user" value="system"/>
<property name="toplink.jdbc.password" value="oracle"/>
<property name="toplink.jdbc.url" value="jdbc:oracle:thin:@127.0.0.1:1521:orcl"/>
<property name="toplink.jdbc.driver" value="oracle.jdbc.OracleDriver"/>
<property name="toplink.ddl-generation" value="create-tables"/>
</properties>
</persistence-unit>
</persistence>
Persistence.xml gerado pelo Netbeans para o Eclipselink:
<?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="SePlagPU" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="javax.persistence.jdbc.url" value="jdbc:oracle:thin:@127.0.0.1:1521:orcl"/>
<property name="javax.persistence.jdbc.password" value="oracle"/>
<property name="javax.persistence.jdbc.driver" value="oracle.jdbc.OracleDriver"/>
<property name="javax.persistence.jdbc.user" value="system"/>
<property name="eclipselink.ddl-generation" value="create-tables"/>
</properties>
</persistence-unit>
</persistence>