Question

So my problem is that I need to find all the recently deleted entities of a particular class, that is the entities which have been deleted since a particular timestamp. Specifically, I want to find entities deleted within the last hour.

All my entities have a created and updated timestamp which I maintain correctly with a listener:

@NotNull
@Column(name = "updated")
@Type(type="org.joda.time.contrib.hibernate.PersistentDateTime")
private DateTime updated;

I also use Envers and annotate my entities.

So to guess, my query should start like this:

// Query for deleted bookings
AuditReader reader = AuditReaderFactory.get(entityManager);
AuditQuery query = reader.createQuery()
.forRevisionsOfEntity(Booking.class, false, true)

but I don’t know what to put here to find the deleted Booking’s since a DateTime.

Answer 1

First, get a timestamp for one hour ago (in milliseconds):

long timestamp = (System.getCurrentTimeMillis()) - (60*60*1000);

Then you can query relative to the timestamp:

AuditReader reader = AuditReaderFactory.get(entityManager);
AuditQuery query = reader.createQuery()
.forRevisionsOfEntity(Booking.class, false, true)
.add(AuditEntity.revisionProperty("timestamp").gt(timestamp)
.add(AuditEntity.revisionType().eq(RevisionType.DEL));

List<Object[]> results = query.getResultList();

to get the revision data. Each Object[] has

1. revision meta data (DefaultRevisionEntity or your own class annotated with @RevisionEntity(CustomRevisionListener.class))
2. the entity instance (the Booking in this case)
3. the RevisionType, which we know will always be DEL in this case