Reference Guide

// to any region.
break;
}
}
Notification on Region and Role changes
Applications can express interest in region change notifications using the addListener(...) API in
RegionService and providing an implementation of the RegionListener. A sample listener
implementation is illustrated in the following listing:
Region Listener Example:
import com.hp.sdn.adm.region.RegionListener;
import com.hp.sdn.region.Region;
...
public class RegionListenerImpl implements RegionListener {
...
@Override
public void added(Region region) {
log.debug(“Master of new region: {}”, region.master());
}
@Override
public void removed(Region region) {
log.debug(“Master of removed region: {}”, region.master());
}
}
Similarly applications can express interest in role change notifications using the addListener(...) API
in RoleService and providing an implementation of the RoleListener. A sample listener
implementation is illustrated in the following listing:
Role Listener Example:
import com.hp.sdn.adm.role.RoleEvent;
import com.hp.sdn.adm.role.RoleListener;
...
public class RoleListenerImpl implements RoleListener {
...
@Override
public void rolesAsserted(RoleEvent roleEvent) {
log.debug(“Previous master: {}”, roleEvent.oldMaster());
log.debug(“New master: {}”, roleEvent.newMaster());
log.debug(“Affected datapaths: {}”, roleEvent.datapaths());
}
}
OpenFlow on page 23 for more details. The ControllerService API provides a common facade for
consumers to interact with the OpenFlow Controller. Applications and Services register with the
controller as specific types of listener:
•
DataPathListener—To receive events about datapath connection.
221