Customizing Auditing Entities Columns

Hi,

I am impressed with Spring Data – JPA and I started to replace our application DAL to Spring Data. While migrating I am facing couple of issues and need an expert advice.
Query 1: Our operational entities have auditable columns and it is named as CREATED_BY_USER_ID, LAST_UPDATED_BY_USER_ID, CREATED_DTTM, LAST_UPDATED_DTTM. I tried the following annotation at entity level but it is not helped.

Code:

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@AttributeOverrides({
        @AttributeOverride(name="createdBy", column=@Column(name="CREATED_BY_USER_ID")),
        @AttributeOverride(name="lastModifiedBy", column=@Column(name="LAST_UPDATED_BY_USER_ID")),
        @AttributeOverride(name="createdDate", column=@Column(name="CREATED_DTTM")),
        @AttributeOverride(name="lastModifiedDate", column=@Column(name="LAST_UPDATED_DTTM"))
})
public class ExtendedAbstractAuditable<U, PK extends Serializable> extends AbstractAuditable<U, PK> {
…
}

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Query 2: How to change/override the primary key value generation strategy. I am looking to change the generate value strategy as UUID for my application.

I solved the issue :D Wrote a custom AbstractAuditable class.. thats all...

Code:

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@MappedSuperclass
@Access(AccessType.FIELD)
public class AbstractAuditable<U, PK extends Serializable> implements
                Auditable<U, PK> {

        private static final long serialVersionUID = -7110939966468361300L;

        @Id
        @GeneratedValue(generator = "system-uuid")
        @GenericGenerator(name = "system-uuid", strategy = "uuid")
        private PK id;

        @Basic
        @JoinColumn(name = "CREATED_BY_USER_ID", nullable = true, updatable = false)
        @ManyToOne
        private U createdBy;

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