Fetching revision number before record insertion

[richa.khurana]

Hi,

I have the following requirement-

I have an employee class, which is mapped to table EMPLOYEE, Also this is marked as audited and hence the corresponding audit records goto EMPLOYE_AUD table.

In certain scenarios where employee satisfies a few conditions, we need to tag the employee and store the following information-

Table name : TAG_EMPLOYEE which has following fields coming from tables-

Employee Id from EMPLOYEE

Employee name from EMPLOYEE

REV from EMPLOYEE_AUD

Now, we want to have all these 3 DB operations of inserting/updating an employee record, inserting records in employee_aud and tagging of employee in a single transaction. Also, rev is available to us (in AuditSync's API  beforeCompletion -> executeInSession -> getCurrentRevisionData) when we have persist flag true, i.e. we are about to flush the data.

My query is, can i somehow fetch the revision number which envers is about to create for employee_aud table, before the actual record insertion without losing any of the sequence values in the corresponding rev sequence. Also, would the corresponding solution work in a clustered JVM environment(assuming DB is the same).

Thanks,

Richa.

[hernanbolido]

Hi!

The revision number for all objects in the same transaction should be the revision number from the RevisionEntity.

Regards. Hernán.

[adamw]

Exactly, and the current rev entity is available from audit reader. And it's cluster-safe.

Adam

[richa.khurana]

Thanks a lot for your replies.

Can you elaborate more on the approach. During debugging of code I observed-

In AuditSync->getCurrentRevisionData

public Object getCurrentRevisionData(Session session, boolean persist) {
        // Generating the revision data if not yet generated
        if (revisionData == null) {
            revisionData = revisionInfoGenerator.generate();
        }

        // Saving the revision data, if not yet saved and persist is true
        if (!session.contains(revisionData) && persist) {
            revisionInfoGenerator.saveRevisionData(session, revisionData);
        }

        return revisionData;
    }

We have the revision number generated only when persist is set to true, which is when we are about to flush the data. In case of steps-

1. Create record for Employee and tag_Employee entities

2. Call flush

How can I set the value of column rev=revision no of Employee_aud table in step 1 itself.

Kindly forgive my ignorance in case I am missing out on something as I am a newbie to envers.

Thanks,

Richa.

[adamw]

Please take a look at the AuditReader# getCurrentRevision(Class<T> revisionEntityClass, boolean persist) method in http://docs.jboss.org/envers/api-new/index.html

If you call it with your revision entity's class (DefaultRevisionEnttiy.class if you don't have one) and "true", the returned object .getId() will be the current revision number.

Adam

[richa.khurana]

Thanks a lot Adam and Hernán Chanfreau. This is exactly what i was looking for.