http://oncodesign.io/2012/11/14/a-practical-solution-for-xml-to-relational-mapping

Hyperjaxb3ExampleTestCase.java

    ...
    @Test
    public void testMapping() throws Exception {

        // Hibernate configuration
        Map<String, String> hibernateProperties = new HashMap<String, String>();
        hibernateProperties.put("hibernate.dialect", "org.hibernate.dialect.DerbyTenSevenDialect");
        hibernateProperties.put("hibernate.connection.driver_class", "org.apache.derby.jdbc.EmbeddedDriver");
        hibernateProperties.put("hibernate.connection.url", "jdbc:derby:target/test-database/database;create=true");
        hibernateProperties.put("hibernate.hbm2ddl.auto", "create");

        // initialise Hibernate
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("org.opensourcesoftwareandme", hibernateProperties);
        EntityManager em = emf.createEntityManager();

        // deserialize test XML document
        JAXBElement jaxbElement = (JAXBElement) JAXBContextUtils.unmarshal("org.opensourcesoftwareandme", readFileAsString("src/test/resources/mails.xml"));
        MailsType mails = (MailsType) JAXBElementUtils.getValue(jaxbElement);

        // persist object
        em.getTransaction().begin();
        em.persist(mails);
        em.getTransaction().commit();

        // retrieve persisted object
        MailsType persistedMails = (MailsType) em.createQuery("from MailsType where hjid = 1").getSingleResult();

        assertEquals("[email protected]", persistedMails.getMail().get(0).getEnvelope().getFromEnvelope());
        assertEquals("[email protected]", persistedMails.getMail().get(0).getEnvelope().getTo());

        em.close();
        emf.close();
    }
    ...

mails.xjb

<bindings xmlns="http://java.sun.com/xml/ns/jaxb"
          xmlns:xsi="http://www.w3.org/2000/10/XMLSchema-instance"
          xmlns:xs="http://www.w3.org/2001/XMLSchema"
          version="2.1">
    <bindings schemaLocation="mails.xsd" version="1.0">

        <!-- Generate POJOs that comply with JPA spec -->
        <globalBindings localScoping="toplevel">
            <serializable/>
        </globalBindings>

        <!-- Customise the package name -->
        <schemaBindings>
            <package name="org.opensourcesoftwareandme"/>
        </schemaBindings>

        <!-- rename the From getter & setter to avoid a came conflict -->
        <bindings node="//xs:complexType[@name='envelopeType']">
            <bindings node=".//xs:attribute[@name='From']">
                <property name="FromEnvelope"/>
            </bindings>
        </bindings>

    </bindings>
</bindings>

mails.xsd

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">

    <xsd:element name="mails" type="mailsType"/>

    <xsd:complexType name="mailsType">
        <xsd:sequence minOccurs="0" maxOccurs="unbounded">
            <xsd:element name="mail" type="mailType"/>
        </xsd:sequence>
    </xsd:complexType>

    <xsd:complexType name="mailType">
        <xsd:sequence>
            <xsd:element name="envelope" type="envelopeType"/>
            <xsd:element name="body" type="bodyType"/>
            <xsd:element name="attachment" type="attachmentType"
                         minOccurs="0" maxOccurs="unbounded"/>
        </xsd:sequence>
        <xsd:attribute use="required" name="id" type="xsd:integer"/>
    </xsd:complexType>

    <xsd:element name="header">
        <xsd:complexType>
            <xsd:simpleContent>
                <xsd:extension base="xsd:string">
                    <xsd:attribute ref="name" use="required"/>
                </xsd:extension>
            </xsd:simpleContent>
        </xsd:complexType>
    </xsd:element>

    <xsd:element name="Date" type="xsd:dateTime"/>

    <xsd:complexType name="envelopeType">
        <xsd:sequence>
            <xsd:element name="From" type="xsd:string"/>
            <xsd:element name="To" type="xsd:string"/>
            <xsd:element ref="Date"/>
            <xsd:element name="Subject" type="xsd:string"/>
            <xsd:element ref="header" minOccurs="0" maxOccurs="unbounded"/>
        </xsd:sequence>
        <xsd:attribute name="From" type="xsd:string" use="required"/>
    </xsd:complexType>

    <xsd:simpleType name="bodyType">
        <xsd:restriction base="xsd:string"/>
    </xsd:simpleType>

    <xsd:complexType name="attachmentType">
        <xsd:group ref="attachmentContent"/>
        <xsd:attribute ref="name" use="required"/>
    </xsd:complexType>

    <xsd:group name="attachmentContent">
        <xsd:sequence>
            <xsd:element name="mimetype">
                <xsd:complexType>
                    <xsd:attributeGroup ref="mimeTypeAttributes"/>
                </xsd:complexType>
            </xsd:element>
            <xsd:element name="content" type="xsd:string" minOccurs="0"/>
        </xsd:sequence>
    </xsd:group>

    <xsd:attribute name="name" type="xsd:string"/>

    <xsd:attributeGroup name="mimeTypeAttributes">
        <xsd:attribute name="type" type="mimeTopLevelType" use="required"/>
        <xsd:attribute name="subtype" type="xsd:string" use="required"/>
    </xsd:attributeGroup>

    <xsd:simpleType name="mimeTopLevelType">
        <xsd:restriction base="xsd:string">
            <xsd:enumeration value="text"/>
            <xsd:enumeration value="multipart"/>
            <xsd:enumeration value="application"/>
            <xsd:enumeration value="message"/>
            <xsd:enumeration value="image"/>
            <xsd:enumeration value="audio"/>
            <xsd:enumeration value="video"/>
        </xsd:restriction>
    </xsd:simpleType>

</xsd:schema>

pom-1.xml

   ...
   <build>
        <plugins>
            <plugin>
                <groupId>org.jvnet.hyperjaxb3</groupId>
                <artifactId>maven-hyperjaxb3-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>generate</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
    ...

pom-2.xml

    ...
    <dependencies>
        <dependency>
            <groupId>org.jvnet.hyperjaxb3</groupId>
            <artifactId>hyperjaxb3-ejb-runtime</artifactId>
            <version>0.5.6</version>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>4.1.7.Final</version>
        </dependency>
        <dependency>
            <groupId>org.apache.derby</groupId>
            <artifactId>derby</artifactId>
            <version>10.9.1.0</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.9</version>
        </dependency>
    </dependencies>
    ...