How to retrieve detached @ManyToOne entities with relationship

Question

Hi All,
I am having difficulty retrieving all the Zipcode, Zipname records which have successfully been deployed on Glassfish v2r2, JDK1.6.0_06, MySQL 5.0, Netbeans 6.1 on Windows XP platform.
Below are the relevant EJBs snippets:
package domain;
@Entity
@Table(name="ZIPCODE")
public class Zipcode implements Serializable {
    @Id
    @Column(name="ID")
    private int id;
    public int getId() {
        return id;
    @OneToMany(cascade={CascadeType.ALL}, mappedBy="zipcode", fetch=FetchType.EAGER, targetEntity=Zipname.class)
    private Collection<Zipname> zipnames = new ArrayList<Zipname>();
    public Collection<Zipname> getNames()
     return zipnames;
package domain;
@Entity
@Table(name="ZIPNAME")
public class Zipname implements Serializable {
    @Id
    @Column(name="ID")
    private int id;
    public void setId(int id) {
        this.id = id;
    @ManyToOne(fetch=FetchType.EAGER)
    @JoinColumn(name="ZIPCODE_ID")
    private Zipcode zipcode;
    public Zipcode getZipcode() {
        return zipcode;
package ejb;
@Stateless
public class ZipcodeBean implements ZipcodeRemote {
    @PersistenceContext(unitName="GeographicalDB") private EntityManager manager;
    public void createZipcode(Zipcode zipcode)
       manager.persist(zipcode);
    public Zipcode findZipcode(int pKey)
       Zipcode zipcode = manager.find(Zipcode.class, pKey);
        zipcode.getNames().size();
        return zipcode;
    public List fetchZipcodesWithRelationships()
      List list = manager.createQuery("FROM Zipcode zipcode").getResultList();
      for (Object obj : list)
         Zipcode zipcode = (Zipcode)obj;
         zipcode.getNames().size();
      return list;
@Stateless
public class ZipnameBean implements ZipnameRemote {
    @PersistenceContext(unitName="GeographicalDB") private EntityManager manager;
    public void createZipname(Zipname zipname)
     manager.persist(zipname);
    public Zipname findZipname(int pKey)
        Zipname zipname = manager.find(Zipname.class, pKey);
        zipname.getZipcode().getNames().size();
        return zipname;
    public List fetchZipnamesWithRelationships()
      List list = manager.createQuery("FROM Zipname zipname").getResultList();
      for (Object obj : list)
         Zipname zipname = (Zipname)obj;
         zipname.getZipcode().getNames().size();
      return list;
public class ZipcodeApplicationClient {
    @EJB
    private static ZipcodeRemote zipcodebean;
    private static ZipnameRemote zipnamebean;
    public ZipcodeApplicationClient() {
    public static void main(String[] args) {
        try {
            Zipcode zipcode_1 = new Zipcode();
            zipcode_1.setcode(9001);
            Zipname zipname_1 = new Zipname();
            zipname_1.setName("Harbour Cove");
            zipcode_1.getNames().add(zipname_1);
            zipname_1.setZipcode(zipcode_1);
//          zipnamebean.createZipname(zipname_1);
            zipcodebean.createZipcode(zipcode_1);
            //fetch detached entity without relationship
            Zipcode zipcode_2 = zipcodebean.findZipcode(0);
            System.out.println("zipcode_2.getId(): " + zipcode_2.getId());
            System.out.println("zipcode_2.getCode(): " + zipcode_2.getCode());
            Iterator iterator = zipcode_2.getNames().iterator();
            while (iterator.hasNext())
                System.out.println(iterator.next().toString());
            // output of fetching detached entity without relationship
            zipcode_2.getId(): 0
            zipcode_2.getCode(): 2010
            domain.ZipName@107e9a8
            zipcode_2.getLatitude: -33.883
            zipcode_2.getLongitude(): 151.216
            zipcode_2.getLocality(): Sydney
            //fetch detached entity with relationship
            List list =  zipcodebean.fetchZipcodesWithRelationships(); // line 76         
            // output of fetching detached entity with relationship
                       Caught an unexpected exception!
                       javax.ejb.EJBException: nested exception is: java.rmi.MarshalException: CORBA BAD_PARAM 1330446342 Maybe; nested exception is:
                       java.io.NotSerializableException: ----------BEGIN server-side stack
                       at client.ZipcodeApplicationClient.main(ZipcodeApplicationClient.java:76)
                       -------------------------------------------------------------------------------------------------------------------------------------------( i ) As a result, please advice on how to utilise both fetchZipcodesWithRelationships() & fetchZipnamesWithRelationships() in ZipcodeApplicationClient() to retrieve collections of Zipcodes & Zipnames without encountering this issue?
(ii) I also like to utilise the zipnamebean.createZipnamez(zipname_1) to properly create this entity.
The local firewall has been de-activated. All components reside on the same host.
I have tried various approaches and googled without success.
Your guidances would be very much appreciated.
Many thanks,
Jack

Answer 1

Hi All,
When trying to add multiple Zipnames with the following additional statements at the beginning of ZipcodeApplicationClient:
            Zipcode zipcode_1 = new Zipcode();
            zipcode_1.setcode(9001);
            Zipname zipname_1 = new Zipname();
            zipname_1.setName("Harbour Cove");
            zipcode_1.getNames().add(zipname_1);
            Zipname zipname_2 = new Zipname();
            zipname_2.setName("Fairyland");
            zipcode_1.getNames().add(zipname_2);
            Zipname zipname_3 = new Zipname();
            zipname_3.setName("Wonderland");
            zipcode_1.getNames().add(zipname_3);
            zipname_1.setZipcode(zipcode_1);
            zipname_2.setZipcode(zipcode_1);
            zipname_3.setZipcode(zipcode_1);
            zipcodebean.createZipcode(zipcode_1); // line 49
The whole persistence step (line 49) failed altogether with these output:
Caught an unexpected exception!
javax.ejb.EJBException: nested exception is: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
        java.rmi.RemoteException: null; nested exception is:
        javax.persistence.EntityExistsException:
Exception Description: Cannot persist detached object [domain.Zipname@1a6eaa4].
Class> domain.Zipname Primary Key> [0]
at client.ZipcodeApplicationClient.main(ZipcodeApplicationClient.java:49)Any ideas on why this occur?
Thanks,
Jack