Using offline locking patterns - POJOs in Action: Developing Enterprise Applications with Lightweight Frameworks - page 506

Order attach(Order order);
}
In addition to detaching the order, the detach() method also detaches the order's
restaurant, its line items, and their menu items so that they can be displayed to
the user. There are Hibernate and JDO implementations of this interface.

Using JDO detached objects
Listing 13.2 shows the JDO version of the OrderAttachmentManager . It detaches
orders by using a JdoTemplate to execute a KodoJDODetachObjectCallback , which is
the class we first saw in chapter 7 that uses the Kodo JDO detachment API . Order-
AttachmentManager attaches orders by executing a KodoJDOAttachObjectCallback
that is similar to a KodoJDODetachObjectCallback . The list of fields to detach is
passed into the JDOOrderAttachmentManager using dependency injection.

Listing 13.2 JDOOrderAttachmentManager

public class JDOOrderAttachmentManager implements
OrderAttachmentManager {
private String[] fieldsOrFetchGroups;

private JdoTemplate jdoTemplate;

public JDOOrderAttachmentManager(
JdoTemplate jdoTemplate,
String[] fieldsOrFetchGroups) {
this.jdoTemplate = jdoTemplate;
this.fieldsOrFetchGroups = fieldsOrFetchGroups;
}

public Order detach(Order order) {
return (Order) jdoTemplate
.execute(new KodoJDODetachObjectCallback(
order, fieldsOrFetchGroups));
}

public Order attach(Order order) {
return (Order) jdoTemplate
.execute(new KodoJDOAttachObjectCallback(
order));
}

}

Both the detach() and attach() methods instantiate and execute a JdoCallback
that calls Kodo JDO .