NamedQuery resultList returning objects, but all values are null

Question

I have a table in database with these columns:

   id serial NOT NULL, 
   name character varying(255) NOT NULL, 
   url character varying(255)

The Entity:

    @Entity
    @Table(name = "Topmenu")
    @XmlRootElement
    @NamedQueries({
        @NamedQuery(name = "Topmenu.findAll", query = "SELECT t FROM Topmenu t"),
        @NamedQuery(name = "Topmenu.findById", query = "SELECT t FROM Topmenu t WHERE t.id = :id")})
    public class Topmenu 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)
        @Column(name = "name")
        private String name;
        @Column(name = "url")
        private String url;

        public Topmenu() {
        }

        public Topmenu(Integer id) {
            this.id = id;
        }

        public Topmenu(Integer id, String name) {
            this.id = id;
            this.name = name;
        }

        public Integer getId() {
            return id;
        }

        public void setId(Integer id) {
            this.id = id;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public String getUrl() {
            return url;
        }

        public void setUrl(String url) {
            this.url = url;
        }

        @Override
        public int hashCode() {
            int hash = 0;
            hash += (id != null ? id.hashCode() : 0);
            return hash;
        }

        @Override
        public boolean equals(Object object) {
            // TODO: Warning - this method won't work in the case the id fields are not set
            if(!(object instanceof Topmenu)) {
                return false;
            }
            Topmenu other = (Topmenu) object;
            return !((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id)));
        }

        @Override
        public String toString() {
            return "erates.entity.Topmenu[ id=" + id + " ]";
        }
}

Netbeans generated the JPA Entity for me. I have 5 records in the database. When I do em.createNamedQuery("Topmenu.findAll").getResultList(); I get a List<Topmenu> with 5 entries, but when I do the following, nothing is returned:

for(Topmenu t : em.createNamedQuery("Topmenu.findAll").getResultList()){
    logger.warn(t.getName());
}

The Named query:

@NamedQuery(name = "Topmenu.findAll", query = "Topmenu t FROM Topmenu t")

Output:

2015-06-01 11:23:27,024 WARN erates.beans.TopmenuBean (TopmenuBean.java:33) -
2015-06-01 11:23:27,034 WARN erates.beans.TopmenuBean (TopmenuBean.java:33) -
2015-06-01 11:23:27,045 WARN erates.beans.TopmenuBean (TopmenuBean.java:33) -
2015-06-01 11:23:27,055 WARN erates.beans.TopmenuBean (TopmenuBean.java:33) -
2015-06-01 11:23:27,066 WARN erates.beans.TopmenuBean (TopmenuBean.java:33) -

Are names in the database empty strings, or do they have some values? — Predrag Maric, Jun 01 '15 at 09:55
Can you post `MyEntity` code? Are you sure the data is commited in the database? — Predrag Maric, Jun 01 '15 at 10:24
@PredragMaric I've added the Entity. The data is in the database, when I run `SELECT * FROM myentity` via Postgres SQL tool, I get 5 records — Erates, Jun 01 '15 at 10:30
@JBNizet I've updated it so the error you see is gone and it will compile — Erates, Jun 01 '15 at 10:40
Your for loop is invalid. Show us the real code. Otherwise, we'll chase a bug that exists in the real code but doesn't in the posted code. — JB Nizet, Jun 01 '15 at 10:42
@JBNizet The for loop is just for logging, doesn't really contribute to business logic, but I've fixed that. Here is the real code. I'm a bit hasitant if it comes to showing real code, I prefer showing the code with values replaced. — Erates, Jun 01 '15 at 10:53

score 0 · Answer 1 · answered Jun 03 '15 at 16:05

In my experience, some problems occur when you don't used TypedQueries and need them to be.

Try your code with

for(Topmenu t : em.createNamedQuery("Topmenu.findAll", Topmenu.class).getResultList()){
    logger.warn(t.getName());
}

With the additional parameter, the createNamedQuery will return a TypedQuery instead of a Query.

Let me know if it helps :)

score 0 · Answer 2 · answered Jun 10 '15 at 10:53

This had nothing to do with entities or EntityManager, but with the fact that EclipseLink was weaving. I forgot one detail, being that the EJB getting the Entities was a Remote EJB. So there were errors while Serializing the objects, causing the TopmenuBean getting objects, but wasn't able to deserialize them.

Problem is solved now

NamedQuery resultList returning objects, but all values are null

2 Answers2