java.lang.ClassCastException using JPA Queries

Question

I'm trying to create Java EE web aplication but I have problem getting single result from database. Getting list of results isn't a problem.

    public UserCredentialsDTO findByUsernameAndPassword(String username, String password) {
        EntityManager em = getEntityManager();
        TypedQuery<UserCredentialsDTO> q = em.createNamedQuery("UserCredentialsDTO.findByUsernameAndPassword", UserCredentialsDTO.class);
        //Query q = em.createNamedQuery("UserCredentialsDTO.findByUsernameAndPassword", UserCredentialsDTO.class);
        q.setParameter("un", username);
        q.setParameter("pw", password);
        UserCredentialsDTO r = null;
        try{
            r = q.getSingleResult();                       //This line is a problem
            //r = (UserCredentialsDTO)q.getSingleResult(); 
        } catch(javax.persistence.NoResultException e) {

        }

        return r;
    }

Using both Query and TypedQuery throws java.lang.ClassCastException

java.lang.ClassCastException: wipb.jee.clientdemo.model.UserCredentialsDTO cannot be cast to wipb.jee.clientdemo.model.UserCredentialsDTO

EDIT

UserCredentialsDTO:

@NamedQueries(
        {@NamedQuery(name = "UserCredentialsDTO.findByUsernameAndPassword", query = "select uc from UserCredentialsDTO uc where uc.username=:un and uc.password=:pw")}
)
@Entity
@Table(name="USERCREDENTIALS", schema="APP")
public class UserCredentialsDTO implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String username;
    private String password;
    @OneToMany(mappedBy = "userCredentials", cascade = CascadeType.ALL, fetch = FetchType.EAGER, orphanRemoval = true)
    private List<UserGroupDTO> userGroups =  new LinkedList<>();

//getters and setters

    public void add(UserGroupDTO userGroup) {
        userGroup.setUserCredentials(this);
        this.userGroups.add(userGroup);
    }

    public List<UserGroupDTO> getUserGroups() {
        return userGroups;
    }


}

Can you post code for UserCredentialsDTO? Maybe could be useful to help you. — Lorelorelore, Jun 19 '18 at 14:04

score 0 · Answer 1 · answered Jun 19 '18 at 14:35

0

This looks like an environment issue, where different classloaders are being used for JPA and the rest of the application.

Refer to this thread

answered Jun 19 '18 at 14:35

bhattedon

1,045
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java.lang.ClassCastException using JPA Queries

1 Answers1