The Record<T> notifier provides
notification for object creation, modification, and deletion.
Specifically, these methods:
created - called when an object is
created.
modified - called when an object is
modified.
deleted - called when an object is
deleted.
The methods in this notifier are always called on the master node for an object.
The created and deleted
methods are not called if an object is created and deleted in the same
transaction.
The modified method is only called once per
transaction, even if an object is modified multiple times. The
modified method is not called for objects that are
created or deleted in a transaction.
The deleted method is called before an object is
deleted.
Record<T>Record<T> notifier is explicitly installed on
one of the child types.
Example 10.4. Record notifier
// $Revision: 1.1.2.3 $
package com.kabira.snippets.store;
import com.kabira.platform.ManagedObject;
import com.kabira.platform.Transaction;
import com.kabira.platform.annotation.Managed;
import com.kabira.store.Record;
/**
* Secondary store record notifier
* <p>
* <h2> Target Nodes</h2>
* <ul>
* <li> <b>domainnode</b> = A
* </ul>
*/
public class RecordNotifier
{
@Managed
private static class Parent
{
void increment()
{
m_count++;
}
private long m_count = 0;
};
private static class Child extends Parent { };
private static class Notifier extends Record<Parent>
{
public Notifier()
{
super(Parent.class);
}
@Override
public void deleted(Parent parent)
{
System.out.println("INFO: Deleted " + parent);
}
@Override
public void modified(Parent parent)
{
System.out.println("INFO: Modified " + parent);
}
@Override
public void created(Parent parent)
{
System.out.println("INFO: Created " + parent);
}
}
/**
* Main entry point
* @param args Not used
*/
public static void main (final String [ ] args)
{
new Transaction("Create Child")
{
@Override
protected void run()
{
new Notifier();
m_child = new Child();
}
}.execute();
new Transaction("Modify Child")
{
@Override
protected void run()
{
m_child.increment();
}
}.execute();
new Transaction("Delete Child")
{
@Override
protected void run()
{
ManagedObject.delete(m_child);
m_child = null;
}
}.execute();
}
private static Child m_child;
}
When the Example 10.4, “Record notifier” is run it outputs these messages:
INFO: Created com.kabira.snippets.store.RecordNotifier$Child@106c202d INFO: Modified com.kabira.snippets.store.RecordNotifier$Child@106c202d INFO: Deleted com.kabira.snippets.store.RecordNotifier$Child@106c202d