Listener

public class Listener extends Participant

This class implements the receiving part of the Inform-Listen (n:m) communication pattern offered by RSB. Upon creation the Listener instance has to be provided with the scope of the channel to listen to. The Listener uses the common event handling mechanisms to process incoming events - in particular filtering of incoming events. Each time a event is received from an Informer, an Event object is dispatched to all Handlers associated to the Listener.

Author

swrede, jschaefe, jwienke

Constructors

Listener

Listener(ListenerCreateArgs args)

Creates a listener for a given scope and participant config.

Parameters

args – arguments used to create this instance.

Throws

InitializeException – error initializing the listener

Methods

activate

public void activate()

addFilter

public void addFilter(Filter filter)

Activates the specified filter for this informer.

Parameters

filter – the filter to activate

addHandler

public void addHandler(Handler handler, boolean wait)

Register an event handler on this Listener to be notified about incoming events. All received events will be send to the registered listeners.

Parameters

• handler – the handler instance to be registered

• wait – if set to @c true, this method will return only after the handler has completely been installed and will receive the next available message. Otherwise it may return earlier.

Throws

InterruptedException – if waiting for installation is wanted but interrupted

deactivate

public void deactivate()

getDataType

public Class<?> getDataType()

getFilterIterator

public Iterator<Filter> getFilterIterator()

Returns an iterator overall active filters on this listener.

Returns

filter iterator

getFilters

public List<Filter> getFilters()

Returns the filters currently being active on the listener.

Returns

list of active filters

getHandlerIterator

public Iterator<Handler> getHandlerIterator()

Returns an iterator over all handlers attached to this listener.

Returns

handler iterator

getHandlers

public List<Handler> getHandlers()

Returns a list of handlers attached to this listener.

Returns

list of handlers

getKind

public String getKind()

getTransportUris

public Set<URI> getTransportUris()

isActive

public boolean isActive()

removeHandler

public void removeHandler(Handler handler, boolean wait)

Remove an event listener from this Listener.

Parameters

• handler – the listener instance to be removed.

• wait – if set to @c true, this method will return only after the handler has been completely removed from the event processing and will not be called anymore from this listener.

Throws

InterruptedException – thrown if the method is interrupted while waiting for the handler to be removed