<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
........
        
        <property name="connection.datasource">SampleDS</property>

    </session-factory>
</hibernate-configuration>

@Getter
@Setter
@Entity
@Table(name="reader")
public class ReaderDomain implements Serializable
{
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="id")
    private Long id;

    @Column(name="lastName")
    private String lastName;

    @Column(name="firstName")
    private String firstName;

    @Column(name="phone")
    private String phone;

    @Column(name="address")
    private String address;
}

public class HibernateUtil {
    private static SessionFactory sessionFactory = null;
    private static ServiceRegistry serviceRegistry;

    public static SessionFactory getSessionFactory() {
        if (sessionFactory == null)
            createSessionFactory();
        return sessionFactory;
    }

    private static void createSessionFactory() {
        try {
            Configuration configuration = new Configuration();
            configuration.configure();
            serviceRegistry = new StandardServiceRegistryBuilder().applySettings(
                    configuration.getProperties()).build();
            sessionFactory = configuration.buildSessionFactory(serviceRegistry);
        } catch (Exception ex) {
            Logic.MyLogger.getMyLogger().write("HibernateUtil1" + ex.toString());
        }
    }
}

........  и везде, где мне нужна ЬД, делать вот такие штуки

class x {
    public void go () {
        ....
        try {
                Session session = HibernateUtil.getSessionFactory().openSession();
             //   работаем с БД 
        .....
        } catch (Exception e) {
            .......
        } finally {
            if (session != null && session.isOpen()) {
                session.close();
            }
        }
    }

}

    @PersistenceContext
    protected EntityManager entityManager;

    @PersistenceContext
    protected EntityManager entityManager;

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>

    <session-factory>
        <property name="hibernate.bytecode.use_reflection_optimizer">false</property>
        <property name="hibernate.connection.datasource">javax.sql.DataSource</property>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.password">123</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/Library</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="show_sql">false</property>
        <property name="connection.pool_size">10</property>
    </session-factory>
</hibernate-configuration>

<?xml version="1.0" encoding="UTF-8" ?>
<entity-mappings version="2.1"
                 xmlns="http://xmlns.jcp.org/xml/ns/persistence/orm"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                 xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence/orm
        http://www.oracle.com/webfolder/technetwork/jsc/xml/ns/persistence/orm_2_1.xsd">
    <description>JPA</description>
    <persistence-unit-metadata>
        <persistence-unit-defaults>
            <entity-listeners>
                <entity-listener class="javax.persistence.EntityListeners">
                </entity-listener>
            </entity-listeners>
        </persistence-unit-defaults>
    </persistence-unit-metadata>
</entity-mappings>