I'd like to know how can use a validation with a message for unique=true in my entity.
@Entity
@Table(name="employees")
public class Employee implements Serializable {
...
@NotEmpty(message = "it cannot be empty")
@Column(name="identification_number", nullable=false, unique=true)
// a message with (message = "the identification number already exist") but i'dont know how implement
private String numeroIdentificacion;
...