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

Class FileWatcherDiscoveryAgent

java.lang.Object

org.apache.qpid.jms.provider.discovery.file.FileWatcherDiscoveryAgent

All Implemented Interfaces:

DiscoveryAgent

public class FileWatcherDiscoveryAgent
extends Object
implements DiscoveryAgent

Discovery agent that watches a file and periodically reads in remote URIs from that file.

Constructor Summary

Constructors

Constructor	Description
FileWatcherDiscoveryAgent(URI discoveryURI)

Method Summary

Modifier and Type	Method	Description
void	close()	Stops the agent after which no new remote peers will be found.
DiscoveryListener	getDiscoveryListener()
URI	getDiscvoeryURI()
int	getUpdateInterval()
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	setUpdateInterval(int updateInterval)
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.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

FileWatcherDiscoveryAgent

public FileWatcherDiscoveryAgent(URI discoveryURI)
                          throws URISyntaxException

Throws:

URISyntaxException

Method Detail

setDiscoveryListener

public void setDiscoveryListener(DiscoveryListener listener)

Description copied from interface: DiscoveryAgent

Sets the discovery listener

Specified by:

setDiscoveryListener in interface DiscoveryAgent

Parameters:

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

getDiscoveryListener

public DiscoveryListener getDiscoveryListener()

isSchedulerRequired

public boolean isSchedulerRequired()

Description copied from interface: DiscoveryAgent

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

Specified by:

isSchedulerRequired in interface DiscoveryAgent

Returns:

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

setScheduler

public void setScheduler(ScheduledExecutorService scheduler)

Description copied from interface: DiscoveryAgent

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.

Specified by:

setScheduler in interface DiscoveryAgent

Parameters:

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

start

public void start()
           throws ProviderException,
                  IllegalStateException

Description copied from interface: DiscoveryAgent

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

Specified by:

start in interface DiscoveryAgent

Throws:

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

IllegalStateException - if the agent is not properly configured.

close

public void close()

Description copied from interface: DiscoveryAgent

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.

Specified by:

close in interface DiscoveryAgent

suspend

public void suspend()

Description copied from interface: DiscoveryAgent

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.

Specified by:

suspend in interface DiscoveryAgent

resume

public void resume()

Description copied from interface: DiscoveryAgent

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.

Specified by:

resume in interface DiscoveryAgent

toString

public String toString()

Overrides:

toString in class Object

getDiscvoeryURI

public URI getDiscvoeryURI()

Returns:

the original URI used to create the Discovery Agent.

getUpdateInterval

public int getUpdateInterval()

Returns:

the configured resource update interval.

setUpdateInterval

public void setUpdateInterval(int updateInterval)

Parameters:

updateInterval - the update interval to use for watching resources for changes.