org.opensaml.util.resource

Class ResourceChangeWatcher

java.lang.Object

java.util.TimerTask

org.opensaml.util.resource.ResourceChangeWatcher

All Implemented Interfaces:

Runnable

public class ResourceChangeWatcher
extends TimerTask

A watcher that invokes a callback when a resource update/deletion has been detected.

Field Summary

Fields

Modifier and Type	Field and Description
private int	currentRetryAttempts Number of times the resource has been polled but generated an error.
static int	DEFAULT_MAX_RETRY_ATTEMPTS Default maximum retry attempts, 0.
static long	DEFAULT_POLL_FREQUENCY Default polling frequency, 12 hours.
private org.joda.time.DateTime	lastModification Last time the resource was modified.
private org.slf4j.Logger	log Class logger.
private int	maxRetryAttempts Max number of polls to try before considering the resource inaccessible.
private long	pollFrequency Frequency, in milliseconds, the resource is polled for changes.
private boolean	resourceExist Whether the resource currently exists.
private List<ResourceChangeListener>	resourceListeners Registered listeners of resource change notifications.
private Resource	watchedResource Resource being watched.

Constructor Summary

Constructors

Constructor and Description
ResourceChangeWatcher(Resource resource) Constructor.
ResourceChangeWatcher(Resource resource, long pollingFrequency) Constructor.
ResourceChangeWatcher(Resource resource, long pollingFrequency, int retryAttempts) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
long	getPollingFrequency() Gets the frequency, in milliseconds, the watched resource should be polled.
List<ResourceChangeListener>	getResourceListeners() Gets the list of registered resource listeners.
void	run()
protected void	signalListeners(ResourceChangeListener.ResourceChange changeType) Signals all registered listeners of a resource change.

Methods inherited from class java.util.TimerTask

cancel, scheduledExecutionTime

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_POLL_FREQUENCY

public static final long DEFAULT_POLL_FREQUENCY

Default polling frequency, 12 hours.

See Also:

Constant Field Values

DEFAULT_MAX_RETRY_ATTEMPTS

public static final int DEFAULT_MAX_RETRY_ATTEMPTS

Default maximum retry attempts, 0.

See Also:

Constant Field Values

log

private final org.slf4j.Logger log

Class logger.

watchedResource

private Resource watchedResource

Resource being watched.

pollFrequency

private long pollFrequency

Frequency, in milliseconds, the resource is polled for changes.

maxRetryAttempts

private int maxRetryAttempts

Max number of polls to try before considering the resource inaccessible.

currentRetryAttempts

private int currentRetryAttempts

Number of times the resource has been polled but generated an error.

resourceExist

private boolean resourceExist

Whether the resource currently exists.

lastModification

private org.joda.time.DateTime lastModification

Last time the resource was modified.

resourceListeners

private List<ResourceChangeListener> resourceListeners

Registered listeners of resource change notifications.

Constructor Detail

ResourceChangeWatcher

public ResourceChangeWatcher(Resource resource)
                      throws ResourceException

Constructor.

Parameters:

resource - the resource to be watched

Throws:

ResourceException - thrown if resource existence or last modification time can not be determined

ResourceChangeWatcher

public ResourceChangeWatcher(Resource resource,
                     long pollingFrequency)
                      throws ResourceException

Constructor.

Parameters:

resource - the resource to be watched

pollingFrequency - the frequency, in milliseconds, to poll the resource for changes

Throws:

ResourceException - thrown if resource existence or last modification time can not be determined

ResourceChangeWatcher

public ResourceChangeWatcher(Resource resource,
                     long pollingFrequency,
                     int retryAttempts)
                      throws ResourceException

Constructor.

Parameters:

resource - the resource to be watched

pollingFrequency - the frequency, in milliseconds, to poll the resource for changes

retryAttempts - maximum number of poll attempts before the resource is considered inaccessible

Throws:

ResourceException - thrown if resource existence or last modification time can not be determined

Method Detail

getPollingFrequency

public long getPollingFrequency()

Gets the frequency, in milliseconds, the watched resource should be polled.

Returns:

frequency the watched resource should be polled

getResourceListeners

public List<ResourceChangeListener> getResourceListeners()

Gets the list of registered resource listeners. New listeners may be registered with the list or old ones removed.

Returns:

list of registered resource listeners

run

public void run()

Specified by:

run in interface Runnable

Specified by:

run in class TimerTask

signalListeners

protected void signalListeners(ResourceChangeListener.ResourceChange changeType)

Signals all registered listeners of a resource change.

Parameters:

changeType - the resource change type