title: @CreationTimestamp and @UpdateTimestamp not working with JPA 2.0.2
body: <p>Using JPA to interact with MySQL. Code<br>
  ImpsLogEntity class </p>
  
  <pre><code>@Entity
  @Table(name = "imps_log")
  @Getter
  @Setter
  public class ImpsLogEntity extends ImpsLog {}
  </code></pre>
  
  <p>ImpsLog Class </p>
  
  <pre><code>   @Setter
     @Getter
     @JsonIgnoreProperties(ignoreUnknown = true)
     @MappedSuperclass
     @ToString
     public class ImpsLog {
  
        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        @Column(name = "id")
        private Long id;
  
        @Column(name = "amount")
        private BigDecimal amount;
  
        @Column(name = "created_at")
        @CreationTimestamp
        private Date createdAt;
  
        @Column(name = "updated_at")
        @UpdateTimestamp
        private Date updatedAt;
  
      }
  </code></pre>
  
  <p>ImpsLogRepo </p>
  
  <pre><code>public interface ImpsLogRepo extends JpaRepository&lt;ImpsLogEntity, Long&gt; {
      }
  </code></pre>
  
  <p>ImpsLogBo</p>
  
  <pre><code>@Getter
  @Setter
  public class ImpsLogBo extends ImpsLog {
  
    private Error error;
  }
  </code></pre>
  
  <p>AccountMapper (using mapstruct)</p>
  
  <pre><code>@Mapper(componentModel = "spring")
  @DecoratedWith(AccountMapperDecorator.class)
  public interface AccountMapper {
  
  ImpsLogEntity impsLogBoToImpsLogEntity(final ImpsLogBo impsLogBo);
  }
  </code></pre>
  
  <p>To create and save the object : </p>
  
  <pre><code>ImpsLogBo impsLogBo = new ImpsLogBo() ;
  impsLogBo.setAmount(new Bigdecimal(200));
  ImpsLogEntity impsLogEntity = 
  this.accountMapper.impsLogBoToImpsLogEntity(impsLogBo);
  impsLogEntity = this.impsLogRepo.save(impsLogEntity);  
  </code></pre>
  
  <p>SQL create statement for imps_log </p>
  
  <pre><code>CREATE TABLE `imps_log` (
    `id` bigint(20) NOT NULL AUTO_INCREMENT,
    `amount` decimal(15,2) DEFAULT NULL,
    `created_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `updated_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    PRIMARY KEY (`id`),
    KEY `created_at` (`created_at`),
    KEY `updated_at` (`updated_at`)
  )
  </code></pre>
  
  <p>This code gives <strong>org.hibernate.engine.jdbc.spi.SqlExceptionHelper -
  Column 'created_at' cannot be null</strong> error while saving to DB.</p>
  
  <p>*</p>
  
  <blockquote>
    <p><strong>Strange part, as for other entities this annotation works. And for this entity also, this error is not consistent.</strong></p>
  </blockquote>
  
  <p>*</p>