@RequestMapping("/{familyName}/{givenName}")
public @ResponseBody
Composer findComposerByFullName(@PathVariable String familyName, @PathVariable String givenName) {
   return composerService.findComposerByFullName(familyName,givenName));
}

@Entity
@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Composer implements Serializable, Comparable<Composer> {
   private static final long serialVersionUID = 1L;
 
   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   private Long id;
 
   @Basic(optional = true)
   @XmlElement(name = "givenName", required = false)
   @Column(name = "givenName", length = 128)
   private String givenName;
 
   @Basic(optional = true)
   @XmlElement(name = "middleName", required = false)
   @Column(name = "middleName", length = 128)
   private String middleName;
 
   @Basic(optional = false)
   @XmlElement(name = "familyName", required = true)
   @Column(name = "familyName", length = 255)
   private String familyName;
 
   @OneToMany(cascade = CascadeType.ALL, mappedBy = "composer", targetEntity = Work.class, fetch = FetchType.EAGER)
   @XmlElementWrapper(name = "works")
   @XmlElement(name = "work", required = true)
   private Set<Work> works = new HashSet<Work>();

@Entity
@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Work implements Serializable {
 
   private static final long serialVersionUID = 1L;
 
   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   @Basic(optional = false)
   @Column(name = "id", nullable = false)
   private Long id;
 
   @Basic(optional = false)
   @Column(name = "title")
   private String title;
 
   @Basic(optional = true)
   @Temporal(TemporalType.DATE)
   private Date completionDate;
 
   @Basic(optional = true)
   @Temporal(TemporalType.DATE)
   private Date premiereDate;
 
   @Basic(optional = true)
   @Column(name = "instrumentation")
   private String instrumentation;
 
   @ManyToOne(fetch = FetchType.EAGER, optional = false)
   @JoinColumn(name = "COMPOSER_ID")
   private Composer composer;

public class JAXBhelper {
   private Logger logger = LoggerFactory.getLogger(this.getClass());
   public static void main(String[] args) {
      Composer composer = new Composer("Ludwig", "Beethoven");
      composer.setId(123L);
      composer.setOtherName("van");
      composer.setBirthDate(new Date());
      composer.setDeathDate(new Date());
 
      Work work = new Work();
      work.setPremiereDate(new Date());
      work.setCompletionDate(new Date());
      work.setInstrumentation("kazoo, comb, wax paper");
      work.setTitle("Cacophony No. 2.718");
      composer.add(work);
      JAXBhelper helper = new JAXBhelper();
      helper.xmlToStdout(composer);
   }
 
   public void xmlToStdout(Composer composer) {
      try {
         JAXBContext jaxbc = JAXBContext.newInstance(Composer.class);
         Marshaller marshaller = jaxbc.createMarshaller();
         marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
         marshaller.marshal(composer, System.out);
      } catch (JAXBException e) {
         e.printStackTrace();
         this.logger.error(e.getMessage());
      }
   }
}

javax.xml.bind.MarshalException
 - with linked exception:
[com.sun.istack.SAXException2: A cycle is detected in the object graph. This will cause infinitely deep XML: Composer  id:'123' ln:'Beethoven' gn:'Ludwig' mn:'null'
	Cacophony No. 2.718
 -> com.rockhoppertech.marshal.domain.Work@e78ffa9d id=null title='Cacophony No. 2.718' cid=123 -> Composer  id:'123' ln:'Beethoven' gn:'Ludwig' mn:'null'
	Cacophony No. 2.718
]
	at com.sun.xml.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:318)
etc.

@ManyToOne(fetch = FetchType.EAGER, optional = false)
@JoinColumn(name = "COMPOSER_ID")
// prevent a cycle
@XmlTransient
private Composer composer;

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<composer>
    <id>123</id>
    <givenName>Ludwig</givenName>
    <familyName>Beethoven</familyName>
    <works>
        <work>
            <title>Cacophony No. 2.718</title>
            <completionDate>2011-10-26T17:28:04.994-04:00</completionDate>
            <premiereDate>2011-10-26T17:28:04.994-04:00</premiereDate>
            <instrumentation>kazoo, comb, wax paper</instrumentation>
        </work>
    </works>
</composer>

public void saveXML(Composer composer, String fileName) {
   try {
      JAXBContext jaxbc = JAXBContext.newInstance(Composer.class);
      Marshaller marshaller = jaxbc.createMarshaller();
      marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
      OutputStream out = null;
      try {
         out = new FileOutputStream(fileName);
         marshaller.marshal(composer, out);
      } catch (FileNotFoundException e) {
         e.printStackTrace();
      } finally {
         try {
            out.close();
         } catch (IOException e) {
         }
      }
   } catch (JAXBException e) {
      e.printStackTrace();
      this.logger.error(e.getMessage());
   }
}
 
public Composer readComposerXML(String fileName) {
   Composer composer = null;
   try {
      JAXBContext jaxbc = JAXBContext.newInstance(Composer.class);
      Unmarshaller marshaller = jaxbc.createUnmarshaller();
      InputStream file = null;
      try {
         file = new FileInputStream(fileName);
         composer = (Composer) marshaller.unmarshal(file);
      } catch (FileNotFoundException e) {
         e.printStackTrace();
         this.logger.error(e.getMessage());
      } finally {
         try {
            file.close();
         } catch (IOException e) {
         }
      }
 
   } catch (JAXBException e) {
      e.printStackTrace();
      this.logger.error(e.getMessage());
   }
   return composer;
}

...
helper.saveXML(composer, "composer.xml");
Composer read = helper.readComposerXML("composer.xml");
for(Work w: read.getWorks()) {
   System.out.println("Title: " + w.getTitle());
   System.out.println("Composer: " + w.getComposer());
}

Title: Cacophony No. 2.718
Composer: null

public void afterUnmarshal(Unmarshaller u, Object parent) {
   this.composer = (Composer) parent;
}

@XmlType(name = "ComposerType", propOrder = { "id", "familyName", "givenName",
		"middleName", "works" })
public class Composer implements Serializable, Comparable<Composer> {
...