com.entrust.toolkit.resourcemonitor

Class Resource

java.lang.Object

com.entrust.toolkit.resourcemonitor.Resource

public class Resource
extends java.lang.Object

The Resource class is a representation of a resource that is periodically polled to determine the status of the resource. A resource can encapsulate any type of Java object as long as that Java object implements the PollableResource interface.

For example, the Entrust toolkit for Java defines an object called ManagerTransport which implements the PollableResource interface. The PollableResource interface implements a method called checkstatus() which is used to implement the logic of checking the status of the resource.

The processing of polling the resource happens as follows:

• A Timer object is used to schedule a PollTask based on the number of seconds defined in this constructor. The minimum period is 1 second and the maximum is 604800.
• Polling can be started by using the start() method. When started, the PollableResource's checkStatus() method is called and a ResourceEvent is returned
• If the event type of the ResourceEvent is greater or equal to the value of the notification trigger for this resource the sendNotification() method is called to notify all registered ResourceListeners.
• Each registered ResourceListener's Notification() method is called containing the ResourceEvent. The ResourceEvent is therefore passed to the ResourceListener. Since the ResourceEvent contains the source of the event which is this Resource, any ResourceEventHandlers assocated with the Resource can be used by the ResourceListener.

Note: The ResourceMonitor class implements the ResourceListener interface and can be used to monitor all Resources. See ResourceMonitor for more information.

For polling of the resource to work, at least 1 or more ResourceListener objects should be added into this resource.

Example usage:

 //Create the PollableResource object
 ManagerTransport transport = new ManagerTransport(ip, port);
 
 //Create the Resource with the PollableResource and polling period
 Resource resource = new Resource(60, transport);  //1 minute period
 
 //Set event notification threshold.  In this case, all events will
 //cause a notification to happen 
 resource.setEventTrigger(ResourceEvent.OKAY);
 
 //Each resource should have a ResourceListener attached so that
 //it is notified of polling events.  In this case, the 
 //ResourceMonitor class can be used to listen to all Resources
 ResourceMonitor monitor = new ResourceMonitor();
 
 // Register the Listener with the resource.  
 resource.addResourceListener(monitor);
 
 //Add the appropriate EventHandler.  The ResourceOutputHandler can
 //write the contents of the event message to a FileOutputStream or
 //a PrintWriter.  
 resource.setEventHandler(new ResourceOutputHandler(new FileOutputStream("logfile.log")),ResourceMonitor.SAME_HANDLER_FOR_ALL);
 
 // Each resource can be started independently, or the
 // resource monitor can be used to start/stop all resources.  If
 // the resource monitor is used to start the resources, they must
 // be added into the monitor using the addPolledResource.
 resource.start();
 .
 .
 .
 //To stop the polling
 resource.stop();
 

Since:

7.2

See Also:

ResourceMonitor, ResourceOutputHandler

Field Summary

Fields

Modifier and Type	Field and Description
java.util.ArrayList	m_handler Stores the ResourceEventHandlers which should be used to handle a ResourceEvent notification.
java.util.ArrayList	m_ResourceListener The Resource listeners.

Constructor Summary

Constructors

Constructor and Description
Resource(int delay, PollableResource resource) Create a new Resource

Method Summary

Methods

Modifier and Type	Method and Description
void	addEventHandler(ResourceEventHandler handler) Set the ResourceEventHandler to be used to handle a ResourceEvent.
void	addResourceListener(ResourceListener listener) Registers the given ResourceListener so that it will be notified when an event occurs on this Resource object.
java.util.ArrayList	getEventHandler() Get the ResourceEventHandler which should be used to handle event notification for a Resource
int	getEventTrigger()
int	getPollingInterval()
PollableResource	getResource()
java.util.ArrayList	getResourceListener()
boolean	isStarted()
void	removeEventHandler(ResourceEventHandler handler) Removes the given ResourceEventHandler from the list of ResourceEventHandlers that will be used to handle events for this Resource.
void	removeResourceListener(ResourceListener listener) Removes the given ResourceListener from the list of ResourceListeners that will be notified when an event occurs on this Resource object.
void	sendNotification(ResourceEvent event) Sends a ResourceEvent to any ResourceListeners that have been registered with this Resource.
void	setEventTrigger(int trigger) Sets the level at which event notification is triggered.
void	setPollingInterval(int seconds) Sets the polling interval, which is the length of time between successful calls to the PollableResource.checkStatus(Resource) method.
void	start() Start polling the PollableResource with a frequency specified by the pollingInterval
void	stop() Stop polling the PollableResource

Methods inherited from class java.lang.Object

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

Field Detail

m_ResourceListener

public java.util.ArrayList m_ResourceListener

The Resource listeners. They are called when a ResourceEvent occurs

m_handler

public java.util.ArrayList m_handler

Stores the ResourceEventHandlers which should be used to handle a ResourceEvent notification.

Constructor Detail

Resource

public Resource(int delay,
        PollableResource resource)

Create a new Resource

Parameters:

delay - the length of time in seconds between resource polling

resource - The PollableResource

Method Detail

getResource

public PollableResource getResource()

Returns:

the PollableResource associated with this Resource

setPollingInterval

public void setPollingInterval(int seconds)

Sets the polling interval, which is the length of time between successful calls to the PollableResource.checkStatus(Resource) method. The default is 5 minutes.

The minimum amount of time is 1 second and the maximum is 604800 seconds (1 week).

Parameters:

seconds - The number of seconds ranging from 1...604800. If seconds is less than 1, then it becomes 1, if the value of seconds is greater than 604800, it becomes 604800.

getPollingInterval

public int getPollingInterval()

Returns:

the PollingInterval

addResourceListener

public void addResourceListener(ResourceListener listener)

Registers the given ResourceListener so that it will be notified when an event occurs on this Resource object. The same ResourceListner will not be added twice.

Parameters:

listener - The ResourceListener

removeResourceListener

public void removeResourceListener(ResourceListener listener)

Removes the given ResourceListener from the list of ResourceListeners that will be notified when an event occurs on this Resource object.

Parameters:

listener - The ResourceListener

getResourceListener

public java.util.ArrayList getResourceListener()

Returns:

All the registered ResourceListener objects contained in an ArrayList

isStarted

public boolean isStarted()

Returns:

true if Resource polling has been started, false otherwise

sendNotification

public void sendNotification(ResourceEvent event)
                      throws ResourceEventException

Sends a ResourceEvent to any ResourceListeners that have been registered with this Resource. The order in which ResourceEvents are sent is the same as the order in which the ResourceListeners were added.

Parameters:

event - the ResourceEvent indicating the status of the event

Throws:

ResourceEventException

addEventHandler

public void addEventHandler(ResourceEventHandler handler)

Set the ResourceEventHandler to be used to handle a ResourceEvent.

Parameters:

handler - the handler which will be used to handle ResourceEvents

removeEventHandler

public void removeEventHandler(ResourceEventHandler handler)

Removes the given ResourceEventHandler from the list of ResourceEventHandlers that will be used to handle events for this Resource.

Parameters:

handler - The ResourceEventHandler

getEventHandler

public java.util.ArrayList getEventHandler()

Get the ResourceEventHandler which should be used to handle event notification for a Resource

Returns:

the ResourceEventHandler associated with this Resource

setEventTrigger

public void setEventTrigger(int trigger)

Sets the level at which event notification is triggered.

Each ResourceEvent contains at least the following 4 notification types:

• ResourceEvent.OKAY (0)
• ResourceEvent.WARNING (100)
• ResourceEvent.BUSY (200)
• ResourceEvent.FAILURE (300)

The above list is ordered from less severe types of messages to more severe types of messages. This method therefore sets the threshold value in which event notifications should be sent. Depending on the type of resource being monitored, this may change for each resource.

If this method is not set, then the default value will be ResourceEvent.WARNING. This means that if the resource event type is returned as ResourceEvent.OKAY, no notifications will be sent to any registered ResourceListeners. By default, only messages whose return types are ResourceEvent.WARNING or greater will trigger a notification.

Note: Setting the trigger value too high will disable all notifications.

Parameters:

trigger - the integer value which represent the point at which event notifications should be sent to registered listeners. Must be greater than or equal to 0.

See Also:

ResourceEvent

getEventTrigger

public int getEventTrigger()

Returns:

the value of the event trigger

See Also:

setEventTrigger(int)

start

public void start()

Start polling the PollableResource with a frequency specified by the pollingInterval

stop

public void stop()

Stop polling the PollableResource