jrun.jms.core.messagemgr
Class MessageLeaseHelper

java.lang.Object
  |
  +--jrun.jms.core.messagemgr.MessageLeaseHelper

All Implemented Interfaces:

SchedulableEventListener

public class MessageLeaseHelper

extends java.lang.Object

implements SchedulableEventListener

This is a helper class for registering leases for messages with LeaseManager. The lease is based on the JMSExpiration property of the message.
When the lease expires, the listener's onLeaseExpired() method is invoked with a MessageHandle object passed as the argument.
If JMSExpiration is 0, the message never expires.

Version:

$Revision: 1.8 $ $Date: 2001/09/03 23:43:18 $

Author:

Tim Anderson

See Also:

org.exolab.jms.messagemgr.MessageHandle, org.exolab.jms.messagemgr.MessagePriorityCache, org.exolab.jms.messagemgr.PersistentPriorityCache, org.exolab.jms.lease.LeaseManager, org.exolab.jms.lease.LeaseEventListenerIfc

Constructor Summary

MessageLeaseHelper(DestinationCache listener)
Construct a helper for the specified destination cache.

Method Summary

void	addLease(MessageHandle handle) Add a lease for the handle to notify listener when message expires.
void	addLease(MessageImpl message) Add a lease for message to notify listener when message expires.
void	clear() Clears all leases
protected Logger	getLogger() Return a reference to the logger
void	onSchedulableEvent(java.lang.Object handle, int type) Invoked when a lease has expired.
void	removeLease(MessageImpl message) Remove a lease for a message

Methods inherited from class java.lang.Object

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

Constructor Detail

MessageLeaseHelper

public MessageLeaseHelper(DestinationCache listener)
                   throws MessageLeaseHelperException

Construct a helper for the specified destination cache. It throws the MessageLeaseException if it fails to construct an instance.

Parameters:

listener - the object to notify when a lease expires

Throws:

MessageLeaseHelperException -

Method Detail

addLease

public void addLease(MessageImpl message)

Add a lease for message to notify listener when message expires. The lease uses JMSExpiration property of the message. If this is unset or 0, then no lease is registered. If non-zero, a MessageHandle object is registered with LeaseManager, and the listener will be notified with this object when the lease expires.

Parameters:

message - the message to add a lease for

addLease

public void addLease(MessageHandle handle)

Add a lease for the handle to notify listener when message expires. The lease uses JMSExpiration property of the message. If this is unset or 0, then no lease is registered. If non-zero, a MessageHandle object is registered with LeaseManager, and the listener will be notified with this object when the lease expires.

Parameters:

handle - message handle to add

removeLease

public void removeLease(MessageImpl message)

Remove a lease for a message

Parameters:

message - the message to remove the lease for

clear

public void clear()

Clears all leases

onSchedulableEvent

public void onSchedulableEvent(java.lang.Object handle,
                               int type)

Invoked when a lease has expired.
It removes the local lease, and notifies the listener.

Specified by:

onSchedulableEvent in interface SchedulableEventListener

Parameters:

handle - An instance of MessageHandle

getLogger

protected Logger getLogger()

Return a reference to the logger

Returns:

Logger