2. New Features

Clustering

JBPAPP-8574 - An external mechanism for determining the master status of a SingletonService is now exposed.

JBoss Enterprise Application Platform 5 provides an API to determine if a singleton service is active on a given cluster node. JBoss Enterprise Application Platform 6 includes a similar feature via the org.jboss.as.clustering.singleton.Singleton.isMaster method.

Hibernate / JPA

Obtain an Entity By A Natural Identifier

In the past, you have been able to obtain an entity by an identifier. One of the new features of Hibernate 4.x, which is included as a component of JBoss Enterprise Application Platform 6, is the ability for an application to obtain an entity by using a natural identifier. This feature is provided via the session.byId() and session.bySimpleNaturalId(AAA.class).load methods of the Resource class. The following is a simple example of this feature.

import java.lang.String;

@Entity
public class User {
    @Id
    @GeneratedValue
    Long id;

    @NaturalId
    String system;

    @NaturalId
    String userName;

    ...
}

// use getReference() to create associations...
Resource aResource = (Resource) session.byId( Resource.class ).getReference( 123 );
User aUser = (User) session.byNaturalId( User.class )
        .using( "system", "prod" )
        .using( "userName", "steve" )
        .getReference();
aResource.assignTo( user );


// use load() to pull initialzed data
return session.byNaturalId( User.class )
        .using( "system", "prod" )
        .using( "userName", "steve" )
        .load();