Different cache concurrent strategies for root entity and its collection (Hibernate with EHCache)?
Given example from Hibernate docs and modifying it so that root level entity (Customer) is read-only 开发者_如何学Pythonwhile one of its collections (tickets) is read-write:
@Entity
@Cache(usage = CacheConcurrencyStrategy.READ_ONLY)
public class Customer {
...
@OneToMany(...)
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public SortedSet<Ticket> getTickets() {
return tickets;
}
...
}
Would collection of tickets get refreshed when accessing customer from cache?
If you modify one of the tickets
of a given Customer
somewhere else, yes. Why don't you test this? Let's assume Cutomer#1
has Ticket#1
and Ticket#2
in its tickets
collection. I ran this code:
// loading in first session
Session session1 = HibernateUtil.getSession();
Transaction tx1 = session1.beginTransaction();
Customer c1 = (Customer) session1.load(Customer.class, 1L); // loads from db and puts in cache
for (Ticket ticket : c1.getTickets()) { // caches q2742145.Customer.tickets#1
System.out.println(ticket);
}
Ticket ticket = (Ticket) session1.load(Ticket.class, 1L); // doesn't hit the db
ticket.setName("foo"); // do some change on Ticket#1
session1.save(ticket);
tx1.commit(); // Ticket#1 gets updated in the db and the cached association invalidated
// loading in second session
Session session2 = HibernateUtil.getSession();
Transaction tx2 = session2.beginTransaction();
Customer c2 = (Customer) session2.load(Customer.class, 1L); // hits the cache
Set<Ticket> tickets = c2.getTickets();
for (Ticket ticket2 : tickets) { // reloads tickets from db
System.out.println(ticket2);
}
tx2.commit();
Which shows the collection of tickets gets "refreshed".
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