com.aquenos.epics.jackie.client.beacon

Interface BeaconDetector

All Known Implementing Classes:

DefaultBeaconDetector

public interface BeaconDetector

Detector for beacons sent by Channel Access servers. The beacon detector listens for beacons sent by Channel Access servers and tries to detect anomalies in the receive pattern. If it detects an anomaly, it notifies the corresponding listeners which have been registered with the beacon detector.

An implementation of this interface should ensure that the methods defined by this interface are thread safe and thus can be called by any thread.

An implementation of this interface may decide to process add and remove requests for listeners asynchronously. This means, that a listener that has just been added might not receive notifications immediately and that a listener that has just been removed might still receive notifications for a while.

The beacon detector may keep references to the listeners registered with it in the form of strong or weak references. This means that code registering a listener should always remove the listener explicitly if it is not needed any longer, but should still keep a strong reference to it as long as it wants to keep the listener alive.

Author:

Sebastian Marsching

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	BeaconDetector.BeaconAnomalyListener Listener for a beacon anomaly.
static interface	BeaconDetector.BeaconListener Listener that is notified of received beacons.

Method Summary

Methods

Modifier and Type	Method and Description
void	addBeaconAnomalyListener(BeaconDetector.BeaconAnomalyListener listener) Adds beacon anomaly listener.
void	addBeaconListener(InetSocketAddress serverAddress, BeaconDetector.BeaconListener listener) Adds a beacon listener.
void	removeBeaconAnomalyListener(BeaconDetector.BeaconAnomalyListener listener) Removes a beacon anomaly listener.
void	removeBeaconListener(InetSocketAddress serverAddress, BeaconDetector.BeaconListener listener) Removes a beacon listener.

Method Detail

addBeaconAnomalyListener

void addBeaconAnomalyListener(BeaconDetector.BeaconAnomalyListener listener)

Adds beacon anomaly listener. If the listener has already been added, this method does nothing. The beacon detector uses object identity, not equality when deciding whether a listener has been added before. The beacon detector might not keep a strong reference to the listener. This means that the calling code has to keep a strong reference in order to keep the listener from being garbage collected.

Parameters:

listener - beacon anomaly listener (never null).

removeBeaconAnomalyListener

void removeBeaconAnomalyListener(BeaconDetector.BeaconAnomalyListener listener)

Removes a beacon anomaly listener. If the listener has already been removed (or has not been added before), this method does nothing. The beacon detector uses object identity, not equality when deciding which listener should be removed.

Parameters:

listener - beacon anomaly listener that shall be removed (never null).

addBeaconListener

void addBeaconListener(InetSocketAddress serverAddress,
                     BeaconDetector.BeaconListener listener)

Adds a beacon listener. The listener is only added for the specified server address. If the listener has already been added for the same server address, this method does nothing. The beacon detector uses object identity, not equality when deciding whether a listener has been added before. The same listener can be registered for multiple server addresses. The beacon detector might not keep a strong reference to the listener. This means that the calling code has to keep a strong reference in order to keep the listener from being garbage collected.

Parameters:

serverAddress - IP address and port number of the server the listener is registered for (never null).

listener - beacon listener (never null).

removeBeaconListener

void removeBeaconListener(InetSocketAddress serverAddress,
                        BeaconDetector.BeaconListener listener)

Removes a beacon listener. The lister is only removed for the specified server address. If the listener has already been removed (or has not been added for this address before), this method does nothing. The beacon detector uses object identity, not equality when deciding which listener should be removed. If the same listener has been registered for multiple server addresses, it has to be individually removed for each server address.

Parameters:

serverAddress - IP address and port number of the server the listener was originally registered for (never null).

listener - beacon listener that shall be removed (never null ).