Package org.apache.qpid.jms.provider.discovery

Interface DiscoveryAgent

All Known Implementing Classes:

FileWatcherDiscoveryAgent, MulticastDiscoveryAgent

public interface DiscoveryAgent

Interface for all agents used to detect instances of remote peers on the network.

Method Summary

Modifier and Type	Method	Description
void	close()	Stops the agent after which no new remote peers will be found.
boolean	isSchedulerRequired()	Indicates if this DiscoveryAgent requires a ScheduledExecutorService in order to perform its discovery work.
void	resume()	Resumes discovery by this agent if it was previously suspended.
void	setDiscoveryListener(DiscoveryListener listener)	Sets the discovery listener
void	setScheduler(ScheduledExecutorService scheduler)	Provider a ScheduledExecutorService to the DiscoveryAgent that requires a scheduler to perform its discovery work.
void	start()	Starts the agent after which new remote peers can start to be found.
void	suspend()	Suspends the Agent which suppresses any new attempts to discover remote peers until the agent is resumed.

Method Detail

isSchedulerRequired

boolean isSchedulerRequired()

Indicates if this DiscoveryAgent requires a ScheduledExecutorService in order to perform its discovery work.

Returns:

true if the agent requires that its parent provide it with a scheduler.

setScheduler

void setScheduler(ScheduledExecutorService scheduler)

Provider a ScheduledExecutorService to the DiscoveryAgent that requires a scheduler to perform its discovery work. If the agent performs long polling style operations such as a socket read then it should not use the provided scheduler as that could block other agents from performing their own work.

Parameters:

scheduler - An initialized Scheduler service that this agent can use for its work.

setDiscoveryListener

void setDiscoveryListener(DiscoveryListener listener)

Sets the discovery listener

Parameters:

listener - the listener to notify on discovery events, or null to clear.

start

void start()
    throws ProviderException,
           IllegalStateException

Starts the agent after which new remote peers can start to be found.

Throws:

ProviderException - if an IO error occurs while starting the agent.

IllegalStateException - if the agent is not properly configured.

close

void close()

Stops the agent after which no new remote peers will be found. This method should attempt to close any agent resources and if an error occurs it should handle it and not re-throw to the calling entity.

suspend

void suspend()

Suspends the Agent which suppresses any new attempts to discover remote peers until the agent is resumed. If the service is not able to be suspended then this method should not throw an Exception, simply return as if successful.

resume

void resume()

Resumes discovery by this agent if it was previously suspended. If the agent does not support being suspended or is closed this method should simply return without throwing any exceptions.