hb_post3.java

import java.io.Serializable;
import java.util.Date;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.PrePersist;
import javax.persistence.PreUpdate;

@Entity
public class Product implements Serializable {

   @Id
   private Integer id;
   private String nome;
   private String desricao;
   private Date created; 
   private Date updated;

   @PrePersist 
   protected void onCreate() {
      created = new Date();
   }

   @PreUpdate
   protected void onUpdate() {
     updated = new Date();
   }
}