Mandatory setter for primary key in Hibernate with hbm.xml

Question

Is it possible to avoid setter for primary key with Hibernate XML mapping configuration? When annotations are used you don't have to have setter method declared. See example. I'm using Hibernate version 4.1.2.

XML based configuration

public class Entity {
    private Integer id;

    public Integer getId() {
        return id;
    }
}

<class name="Language" table="language">
    <id name="id" column="id">
        <generator class="native" />
    </id>
</class>

While initializing Hibernate exception is thrown

Caused by: org.hibernate.PropertyNotFoundException: Could not find a setter for property id in class net.kreuzman.eshop.core.domain.l10n.Language
    at org.hibernate.property.BasicPropertyAccessor.createSetter(BasicPropertyAccessor.java:252)
    at org.hibernate.property.BasicPropertyAccessor.getSetter(BasicPropertyAccessor.java:245)
    at org.hibernate.mapping.Property.getSetter(Property.java:325)
    at org.hibernate.tuple.entity.PojoEntityTuplizer.buildPropertySetter(PojoEntityTuplizer.java:444)
    at org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:182)
    at org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:82)
... 49 more

Annotation based configuration

@Entity
@Table(name="entity")
public class Entity {
    @Id
    @Column(name="id")
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Integer id;

        public Integer getId() {
             return id;
        }
}

This works well.

@Woody I don't want to declare setter for member which should be never changed by application. Declaring it as `private` seems not nice to me. — michal.kreuzman, Apr 26 '12 at 13:31
I think you need setter, but can't you declare it non-public? (e.g. `protected`). This is just speculation. I am not expert. — Boris Strandjev, Apr 26 '12 at 13:32
@Boris Strandjev yes I can declare it non-public but for what? It will be never used. Seems awkward to me. — michal.kreuzman, Apr 26 '12 at 13:33
@krocan - you are wrong. It will be used, but through reflection. If this seems awkward to you, why declaring a private field without setter in the annotation case does not? — Boris Strandjev, Apr 26 '12 at 13:40

score 4 · Accepted Answer · answered Apr 26 '12 at 13:39

You can set the access type to field, which will achieve the same thing as putting the annotation on the field.

<class name="Language" table="language">
    <id name="id" column="id" access="field">
        <generator class="native" />
    </id>
</class>

score 0 · Answer 2 · answered Apr 26 '12 at 13:34

0

I think hibernate creates objects via reflection (Class.newInstance()) which is why it need the no args constructor. That way - i don't see how its possible to leave out a setter for a used property. U can mark unused fields as @Transient but thats it.

answered Apr 26 '12 at 13:34

hburde

1,441
11
6

Yes you right Hibernate creates objects via reflection and you can also setup private member via reflection so you don't need setter method. Anyway it works while using annotations see question. – michal.kreuzman Apr 26 '12 at 13:38
Opps - yep - i used this only once some time ago. – hburde Apr 26 '12 at 13:55

score 0 · Answer 3 · edited Jun 10 '13 at 03:56

0

@GeneratedValue(strategy = GenerationType.IDENTITY)

instead of auto

edited Jun 10 '13 at 03:56

Bohemian

412,405
93
575
722

answered Jun 10 '13 at 03:36

Ravi Sohal

1

Mandatory setter for primary key in Hibernate with hbm.xml

3 Answers3