I am experimenting with JPA and Glassfish 4.0.
I wrote such a user class (only the relevant parts, and I'm not sure if it compiles):
public class User implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "id")
private Integer id;
@Basic(optional = false)
@NotNull
@Size(min = 1, max = 50)
@Column(name = "first_name")
private String firstName;
@JoinColumn(name = "country_id", referencedColumnName = "id")
@ManyToOne(optional = false)
private Country country;
public void setCountry(Country countryId) {
this.country = countryId;
}
}
My TestController (only relevant parts):
@ManagedBean(name = "testController", eager = true)
@RequestScoped
public class TestController implements Serializable {
@EJB
private dk.iqtools.session.UserFacade userFacade;
public String Insert(){
factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
EntityManager em = factory.createEntityManager();
Query cq = em.createQuery("select c from Country c where c.id = 302");
List<Country> countryList = cq.getResultList();
User user = new User();
user.setFirstName("Hans123");
user.setLastName("Knudsen333");
user.setCountry((Country)countryList.get(0)); <- throws an ERROR
user.setPassword("secret");
user.setYearOfBirth(1966);
user.setGender(1);
user.setEmail("haps@hfhfh.dk2243");
userFacade.create(user);
return "";
}
And my country bean is just a simple bean with simple attributes located in:
dk.iqtools.entity
In general, it works, but if I encounter an error in my code, I persistently get the following error:
Caused by: java.lang.ClassCastException:
dk.iqtools.entity.Country cannot be cast to dk.iqtools.entity.Country
at dk.iqtools.controller.TestController.Insert(TestController.java:65)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
allegation of violation:
user.setCountry((Country)countryList.get(0));
Can someone tell me why this is happening? If everything works as expected, the user will be inserted into the database. But if for instanse I try to insert a user that already exists, I get a database error.
. , .
GF, .
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