import org.onosproject.ovsdb.controller.OvsdbEventListener; //导入依赖的package包/类
/**
 * Dispatches event to the north.
 *
 * @param clientService OvsdbClientService instance
 * @param newRow        a new row
 * @param oldRow        an old row
 * @param eventType     type of event
 * @param dbSchema      ovsdb database schema
 */
private void dispatchInterfaceEvent(OvsdbClientService clientService,
                                    Row row,
                                    Type eventType,
                                    DatabaseSchema dbSchema) {

    long dpid = getDataPathid(clientService, dbSchema);
    Interface intf = (Interface) TableGenerator
            .getTable(dbSchema, row, OvsdbTable.INTERFACE);
    if (intf == null) {
        return;
    }

    String portType = (String) intf.getTypeColumn().data();
    long localPort = getOfPort(intf);
    if (localPort < 0) {
        return;
    }
    String[] macAndIfaceId = getMacAndIfaceid(intf);
    if (macAndIfaceId == null) {
        return;
    }

    EventSubject eventSubject = new DefaultEventSubject(MacAddress.valueOf(
            macAndIfaceId[0]),
                                                        new HashSet<IpAddress>(),
                                                        new OvsdbPortName(intf
                                                                                  .getName()),
                                                        new OvsdbPortNumber(localPort),
                                                        new OvsdbDatapathId(Long
                                                                                    .toString(dpid)),
                                                        new OvsdbPortType(portType),
                                                        new OvsdbIfaceId(macAndIfaceId[1]));
    for (OvsdbEventListener listener : ovsdbEventListener) {
        listener.handle(new OvsdbEvent<EventSubject>(eventType,
                                                     eventSubject));
    }
}
 

import org.onosproject.ovsdb.controller.OvsdbEventListener; //导入依赖的package包/类
@Override
public void addOvsdbEventListener(OvsdbEventListener listener) {
    if (!ovsdbEventListener.contains(listener)) {
        this.ovsdbEventListener.add(listener);
    }
}
 

import org.onosproject.ovsdb.controller.OvsdbEventListener; //导入依赖的package包/类
@Override
public void removeOvsdbEventListener(OvsdbEventListener listener) {
    this.ovsdbEventListener.remove(listener);
}
 

import org.onosproject.ovsdb.controller.OvsdbEventListener; //导入依赖的package包/类
@Override
public void addOvsdbEventListener(OvsdbEventListener listener) {
    ovsdbEventListener = listener;

}
 

import org.onosproject.ovsdb.controller.OvsdbEventListener; //导入依赖的package包/类
@Override
public void removeOvsdbEventListener(OvsdbEventListener listener) {
    ovsdbEventListener = null;

}
 

import org.onosproject.ovsdb.controller.OvsdbEventListener; //导入依赖的package包/类
@Override
public void addOvsdbEventListener(OvsdbEventListener listener) {

}
 

import org.onosproject.ovsdb.controller.OvsdbEventListener; //导入依赖的package包/类
@Override
public void removeOvsdbEventListener(OvsdbEventListener listener) {

}