Why is the Bean validator throwing ConstraintViolationException on the not nullable but auto-generated id field?

ENTITY CLASS :

public class MyUser implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @NotNull
    @Column(name = "id")
    private Integer id;


    @B开发者_开发百科asic(optional = false)
    @NotNull
    @Size(min = 1, max = 100)
    @Column(name = "name")
    private String name;

    // other attrs and getter-setters


    public MyUser() {
    }

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

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

USAGE CODE :

MyUser myuser = new MyUser();
myuser.setName("abc");

try {
    em.persist(myuser);
} catch (ConstraintViolationException e) {
    System.out.println("size : " + e.getConstraintViolations().size());
    ConstraintViolation<?> violation = e.getConstraintViolations().iterator().next();
    System.out.println("field : " + violation.getPropertyPath().toString());
    System.out.println("type : " + violation.getConstraintDescriptor().getAnnotation().annotationType());
}

OUTPUT :

INFO: size : 1
INFO: field : id
INFO: type : interface javax.validation.constraints.NotNull

ENVIRONMENT :

JDK 6 u23

GlassFish Server Open Source Edition 3.1-b41 (has bean-validator.jar)

NetBeans IDE 7.0 Beta 2

QUESTION :

Does anyone has suggestion on why is the Bean validator throwing this exception on the not nullable but auto-generated id field? What is the right approuch?

With IDENTITY generation, the entity is first inserted in database with a null identifier, and a query is executed afterwards to get the value of the generated ID. So, at insert time, your ID is null and thus violates the NotNull constraint.