Andrew Eells dot com

Hibernate’s @FilterJoinTable

Couldn’t find a completely articulate example or full documentation of how to add a filter to a Hibernate Many-to-Many collection association mapping, so thought I’d would post a complete example here.

It’s possible to apply the filter to the target entity table which is reasonably well documented, or at least you can have an educated guess, but also to the association table of the Many-to-Many relationship where the docs were a little less clear.

I have the following relational association table:

CREATE TABLE departure_point_resort_association (
  departure_point_id      VARCHAR(36) NOT NULL,
  resort_id               VARCHAR(36) NOT NULL,
  site_id                 ENUM('30', '31'...) NOT NULL,
  PRIMARY KEY (departure_point_id, resort_id),
  CONSTRAINT assoc_departure_point_fk FOREIGN KEY (departure_point_id)
    REFERENCES departure_point (id),
  CONSTRAINT assoc_resort_fk FOREIGN KEY (resort_id) REFERENCES resort (id)
);

which is mapping a ski resort to potential departure points or airports. There was no real requirement to persist an actual SITE table (which would be entirely static data) and to map to it’s foreign key value, so instead am using a simple MySQL ENUM column above, and wanted to apply a filter at the application level to the collection of Resorts based on this site_id.

@Entity @Table
@FilterDef(name = "siteFilter", parameters = {
    @ParamDef(name = "siteId", type = "string")
})
public final class Resort extends BasePersistentObject {
    @ManyToMany(fetch = FetchType.EAGER)
    @FilterJoinTable(name = "siteFilter", condition = "site_id = :siteId")
    @JoinTable(name = "DEPARTURE_POINT_RESORT_ASSOCIATION",
            joinColumns = {
                    @JoinColumn(name = "RESORT_ID")
            },
            inverseJoinColumns = {
                    @JoinColumn(name = "DEPARTURE_POINT_ID")
            }
    )
    private Set departurePoints;

Then it’s simply a case of enabling the filter in the client (DAO or whatever your framework dictates):

session.enableFilter("siteFilter").setParameter("siteId",  String.valueOf(siteId));

Tags: Hibernate

Programming for grown-ups

I sent an article by Ted Dziuba of The Register around to my development team earlier this morning. As well as some well-deserved shots at Microsoft, it contained a rather acidic commentary (not like him) on the merits of the PHP programming language. Or rather lack of.

One of my colleagues replied with the following:

http://www.codexon.com/posts/php-53-adds-goto

Hibernate StatelessSession with Transactional Annotation

I have a bi-directional collection mapping in Java which I thought was causing me problems when persisting using Hibernate’s StatelessSession API.

However, it looks as though the issue was being caused by the fact I was using the @Transactional annotation instead. The API states:

“Operations performed via a stateless session bypass Hibernate’s event model and interceptors.”

I didn’t pick up on the importance of the above statement as it’s not particularly clear at first glance, but it looks as though using Annotations via AOP just isn’t supported when streaming directly to the database using the StatelessSession.

Commenting out the annotation and using a programmatic Transaction instead corrected the problem:

//    @Transactional
public List<Package> insertAvailability(final List<Package> packages) {
    final StatelessSession session = sessionFactory.openStatelessSession();
    final Transaction tx = session.beginTransaction();

    session.insert(aPackage);
    // insert collections manually etc...

    tx.commit();
    session.close();

    return packages;
}

Tags: Hibernate