In the previous example i tried to set the list in the ejb, but if removed
and then put the list in the managed bean i get the same behavior
@Named
public class MyBean implements Serializable{
@EJB
private MyEJB ejb;
public void anyMethod(){
User user = ejb.getUserWithRoles();
//i will create a list of role just for try to set any role the userJohn
List<Role> roleList = new ArrayList<Role>(2);
roleList.add(new Role(1,'ADMIN'); //creating and adding role 1
roleList.add(new Role(2,'DEVELOPER');//creating and adding role 2
user.setRoles(roleList);
user.getRoles(); //<---- HERE THE LIST IS ALWAYS NULL
}
}
2013/10/18 José Luis Cetina <maxtorz...@gmail.com>
>
> I have a "strange" behavior, with list properties of any kind of entity.
>
> When i try to set a non empty list to a retrieved entity that has a list
> value with null (because is not fetched) the entity doesnt "reflect" the
> new non-empty values that i set.
>
> Steps
> 1. Retrieve any entity (ex. user) from database in an ejb with criterias.
> 2. The retrieved entity has a OneToMany attribute (roles) by default is
> lazy thats why if i dont do a fetch (i dont) the list is null
> 3. Then try to fill the role list with a NON-EMPTY list
> 4. Here the list that i set has values but the user list has a null in the
> roles list attribute even though i set it in the step 3
>
>
> I dont know why this is happening, the only way i could fix this is
> cloning (using SerializationUtils from Apache commons.lang3) the user
> entity (see the steps) and with this work, but i dont know why.
>
> 1. Retrieve any entity (ex. user) from database in an ejb with criterias.
> 2. Clone retrieved entity and asig to new one User clonedUser =
> SerializationUtils.clone(originalRetrivedUser);
> 3. Then try to fill the role list with a NON-EMPTY list to the clonedUser
> 4. The list of clonedUser has the correct values
>
>
> Why i need to clone? why i cannot set a list to the entity if is not
> cloned?
>
>
> Im using Apache TomEE 1.6.0-SNAPSHOT (with the openjpa version embedded)
>
>
> Scenario:
>
> ***** ENTITIES *****
> @Entity
> public class User implements Serializable{
>
> @Id
> private int id;
> private String userName;
> private String password;
> @OneToMany(mappedBy = "user")
> private List<Role> roles;
>
> //getters and setters..
>
> }
>
>
> @Entity
> public class Role implements Serializable{
>
> @Id
> private int id;
> private String roleName;
> @ManyToOne
> @JoinColumn(name = "user_id")
> private User user;
>
> //getters and setters..
> }
>
>
> **** EJB CLASS ****
> @Stateless
> public class MyEJB{
>
> @PersistenceContext(unitName ="ANY_NAME")
> private EntityManager em;
>
> public User getUserWithRoles(){
>
> CriteriaBuilder cb = em.getCriteriaBuilder();
> CriteriaQuery<User> cq = cb.createQuery(User.class);
> Root<User> root = cq.from(User.class);
>
> cq.where(cb.equal(root.get(User_.userName),"john"));
>
> User userJohn = em.createQuery(cq).getSingleResult(); // if i want
> this work i have to do User userJohn =
> SerializationUtils.clone(em.createQuery(cq).getSingleResult()); [1*]
>
>
> //i will create a list of role just for try to set any role the
> userJohn
> List<Role> roleList = new ArrayList<Role>(2);
> roleList.add(new Role(1,'ADMIN'); //creating and adding role 1
> roleList.add(new Role(2,'DEVELOPER');//creating and adding role 2
>
> //setting the list of roles created to the user, as you can see the
> list has 2 values but the value roles of userJohn always is set to null, my
> setters and getters are correct
> userJohn.setRoles(roleList);
>
> return userJohn;
> }
>
> }
>
> *** MANAGED BEAN ****
>
> @Named
> public class MyBean implements Serializable{
>
> @EJB
> private MyEJB ejb;
>
> public void anyMethod(){
> User user = ejb.getUserWithRoles();
> user.getRoles(); //<---- HERE THE LIST IS ALWAYS NULL but if i use
> clone in the ejb method (see 1*) i can get the corrected values.
>
> }
>
>
> }
>
> I know i can get the values fetching but im trying to not do it
>
--
-------------------------------------------------------------------
*SCJA. José Luis Cetina*
-------------------------------------------------------------------
