de.danet.an.workflow.api
Interface EventSubscriber

All Superinterfaces:

WfObject

public interface EventSubscriber

extends WfObject

An EventSubscriber represents a connection to the workflow engine's event queue. From its creation with WorkflowService.createEventSubscriber until its destruction with WorkflowService.release all events from the workflow engine are delivered to the EventSubscriber. EventSubscribers should be released using WorkflowService.release when no longer needed as they may consume considerable resources.

Version:

$Revision: 1.3 $

Author:

Michael Lipp

Method Summary

WfAuditEvent	receive() Receives the next audit event.
WfAuditEvent	receive(long timeout) Receives the next audit event that arrives within the specified timeout interval.
WfAuditEvent	receiveNoWait() Receives the next audit event if one is immediately available.
void	setEventHandler(WfAuditHandler handler) Sets a handler for received events that is automatically invoked.

Method Detail

receive

public WfAuditEvent receive()
                     throws java.io.IOException

Receives the next audit event. This method blocks until the next event is received.

Returns:

the audit event

Throws:

java.io.IOException - if an error occurs

receive

public WfAuditEvent receive(long timeout)
                     throws java.io.IOException

Receives the next audit event that arrives within the specified timeout interval.

Parameters:

timeout - the timeout value (in milliseconds). If 0, the method blocks until a message is received.

Returns:

the audit event or null if the timeout expires

Throws:

java.io.IOException - if an error occurs

receiveNoWait

public WfAuditEvent receiveNoWait()
                           throws java.io.IOException

Receives the next audit event if one is immediately available.

Returns:

the audit event or null if no event is available

Throws:

java.io.IOException - if an error occurs

setEventHandler

public void setEventHandler(WfAuditHandler handler)
                     throws java.io.IOException

Sets a handler for received events that is automatically invoked. If a handler has been set, the receive methods may not be called.

Parameters:

handler - the event handler

Throws:

java.io.IOException - if an error occurs