org.xmlBlaster.client
Class StreamingCallback

java.lang.Object
  org.xmlBlaster.client.StreamingCallback

All Implemented Interfaces:

I_Callback, I_ConnectionStateListener, I_Timeout

public class StreamingCallback

extends java.lang.Object

implements I_Callback, I_Timeout, I_ConnectionStateListener

StreamingCallback

Author:

Michele Laghi

Nested Class Summary

(package private) class	StreamingCallback.ExecutionThread
(package private) class	StreamingCallback.Writer Writer needed since the out stream must be written from a thread which does not die before the thread which reads the in counterpart.

Field Summary

private I_StreamingCallback	callback
private java.lang.String	cbSessionId
static java.lang.String	ENTRY_CB_SESSION_ID
private XmlBlasterException	ex
private Global	global
private java.io.PipedInputStream	in
private boolean	initialized
private boolean	lastMessageCompleted
private static java.util.logging.Logger	log
private EDU.oswego.cs.dl.util.concurrent.Mutex	mutex
private java.io.PipedOutputStream	out
private I_Queue	queue
private java.lang.String	ret
private Timeout	timer
private Timestamp	timestamp
private boolean	useQueue
private long	waitForChunksTimeout The time to wait in ms until returning when waiting (if zero or negative inifinite)
private StreamingCallback.Writer	writer

Constructor Summary

StreamingCallback(Global global, I_StreamingCallback callback)

StreamingCallback(Global global, I_StreamingCallback callback, long waitForChunksTimeout, long waitForClientReturnTimeout, boolean useQueue)

Method Summary

private void	clearQueue()
private void	consumeExceptionIfNotNull() returns the exception (if any) and resets it.
private ClientProperty	getProp(java.lang.String key, UpdateQos qos)
private boolean	isFirstChunk(UpdateQos qos)
private boolean	isLastChunk(UpdateQos qos)
void	reachedAlive(ConnectionStateEnum oldState, I_XmlBlasterAccess connection) This is the callback method invoked from XmlBlasterAccess notifying the client that a connection has been established and that its status is now ALIVE.
void	reachedDead(ConnectionStateEnum oldState, I_XmlBlasterAccess connection) This is the callback method invoked from XmlBlasterAccess informing the client that the connection was lost (i.e.
void	reachedPolling(ConnectionStateEnum oldState, I_XmlBlasterAccess connection) This is the callback method invoked from XmlBlasterAccess informing the client that the connection state has changed to POLLING.
private void	reset()
int	sendInitialQueueEntries()
private void	setException(java.lang.Throwable ex) Always makes a USER_UPDATE_HOLDBACK Exception out of it, no matter what the original exception was.
private void	storeEntry(java.lang.String cbSessId, UpdateKey key, byte[] cont, UpdateQos qos)
void	timeout(java.lang.Object userData) It is used here to inform the user update method that a timeout occured, it will throw an IOException when reading the in stream of the update method.
java.lang.String	update(java.lang.String cbSessId, UpdateKey updKey, byte[] cont, UpdateQos updQos) This is the callback method invoked from I_XmlBlasterAccess informing the client in an asynchronous mode about a new message.
private java.lang.String	updateInternal(java.lang.String cbSessId, UpdateKey updKey, byte[] cont, UpdateQos updQos, boolean isExternal)
java.lang.String	updateNewMessage(java.lang.String cbSessId, UpdateKey updKey, byte[] cont, UpdateQos updQos)
java.lang.String	updateStraight(java.lang.String cbSessId, UpdateKey updKey, byte[] cont, UpdateQos updQos)

Methods inherited from class java.lang.Object

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

Field Detail

log

private static java.util.logging.Logger log

ENTRY_CB_SESSION_ID

public static final java.lang.String ENTRY_CB_SESSION_ID

See Also:

Constant Field Values

callback

private I_StreamingCallback callback

global

private Global global

out

private java.io.PipedOutputStream out

in

private java.io.PipedInputStream in

ex

private XmlBlasterException ex

ret

private java.lang.String ret

cbSessionId

private java.lang.String cbSessionId

writer

private StreamingCallback.Writer writer

waitForChunksTimeout

private long waitForChunksTimeout

The time to wait in ms until returning when waiting (if zero or negative inifinite)

timer

private Timeout timer

timestamp

private Timestamp timestamp

queue

private I_Queue queue

useQueue

private boolean useQueue

initialized

private boolean initialized

lastMessageCompleted

private boolean lastMessageCompleted

mutex

private final EDU.oswego.cs.dl.util.concurrent.Mutex mutex

Constructor Detail

StreamingCallback

public StreamingCallback(Global global,
                         I_StreamingCallback callback)
                  throws XmlBlasterException

StreamingCallback

public StreamingCallback(Global global,
                         I_StreamingCallback callback,
                         long waitForChunksTimeout,
                         long waitForClientReturnTimeout,
                         boolean useQueue)
                  throws XmlBlasterException

Parameters:

callback -

Method Detail

reset

private void reset()
            throws XmlBlasterException

Throws:

XmlBlasterException

sendInitialQueueEntries

public final int sendInitialQueueEntries()
                                  throws XmlBlasterException

Returns:

the number of delivered entries from local client update queue.

Throws:

XmlBlasterException

storeEntry

private final void storeEntry(java.lang.String cbSessId,
                              UpdateKey key,
                              byte[] cont,
                              UpdateQos qos)
                       throws XmlBlasterException

Throws:

XmlBlasterException

updateStraight

public java.lang.String updateStraight(java.lang.String cbSessId,
                                       UpdateKey updKey,
                                       byte[] cont,
                                       UpdateQos updQos)
                                throws XmlBlasterException,
                                       java.io.IOException

Throws:

XmlBlasterException

java.io.IOException

See Also:

I_Callback.update(java.lang.String, org.xmlBlaster.client.key.UpdateKey, byte[], org.xmlBlaster.client.qos.UpdateQos)

updateNewMessage

public java.lang.String updateNewMessage(java.lang.String cbSessId,
                                         UpdateKey updKey,
                                         byte[] cont,
                                         UpdateQos updQos)
                                  throws XmlBlasterException,
                                         java.io.IOException

Throws:

XmlBlasterException

java.io.IOException

See Also:

I_Callback.update(java.lang.String, org.xmlBlaster.client.key.UpdateKey, byte[], org.xmlBlaster.client.qos.UpdateQos)

isFirstChunk

private final boolean isFirstChunk(UpdateQos qos)

isLastChunk

private final boolean isLastChunk(UpdateQos qos)

getProp

private final ClientProperty getProp(java.lang.String key,
                                     UpdateQos qos)

update

public java.lang.String update(java.lang.String cbSessId,
                               UpdateKey updKey,
                               byte[] cont,
                               UpdateQos updQos)
                        throws XmlBlasterException

Description copied from interface: I_Callback

This is the callback method invoked from I_XmlBlasterAccess informing the client in an asynchronous mode about a new message.

So you should implement in your client code the I_Callback interface - suppling the update() method where you can do with the message whatever you want.

The raw protocol driver specific update() method (e.g. CORBA-BlasterCallback.update()) is unpacked and for each arrived message this update is called.

Specified by:

update in interface I_Callback

Parameters:

cbSessId - The session ID specified by the client which registered the callback. You can specify a cbSessionId during connection (with ConnectQos) and this is bounced back here so you can authenticate the message.

updKey - The arrived key containing the topic name

cont - The arrived message content. This is your payload.

Throws:

XmlBlasterException

See Also:

I_Callback.update(java.lang.String, org.xmlBlaster.client.key.UpdateKey, byte[], org.xmlBlaster.client.qos.UpdateQos)

updateInternal

private final java.lang.String updateInternal(java.lang.String cbSessId,
                                              UpdateKey updKey,
                                              byte[] cont,
                                              UpdateQos updQos,
                                              boolean isExternal)
                                       throws XmlBlasterException

Throws:

XmlBlasterException

See Also:

I_Callback.update(java.lang.String, org.xmlBlaster.client.key.UpdateKey, byte[], org.xmlBlaster.client.qos.UpdateQos)

timeout

public void timeout(java.lang.Object userData)

It is used here to inform the user update method that a timeout occured, it will throw an IOException when reading the in stream of the update method.

Specified by:

timeout in interface I_Timeout

Parameters:

userData - You get bounced back your userData which you passed with Timeout.addTimeoutListener()

See Also:

I_Timeout.timeout(java.lang.Object)

clearQueue

private final void clearQueue()

setException

private void setException(java.lang.Throwable ex)

Always makes a USER_UPDATE_HOLDBACK Exception out of it, no matter what the original exception was.

Parameters:

ex -

consumeExceptionIfNotNull

private void consumeExceptionIfNotNull()
                                throws XmlBlasterException

returns the exception (if any) and resets it.

Returns:

Throws:

XmlBlasterException

reachedAlive

public void reachedAlive(ConnectionStateEnum oldState,
                         I_XmlBlasterAccess connection)

Description copied from interface: I_ConnectionStateListener

This is the callback method invoked from XmlBlasterAccess notifying the client that a connection has been established and that its status is now ALIVE.

Note that this method is invoked also when the connection has been established the first time. In this case the connection is fully operational but your connect() call has not yet returned. You can access the returned connect QoS in this case with connect.getConnectReturnQos().

You can erase all entries of the queue manually or add others before you return and in this way control the behavior. During you have control in reachedAlive() the client side queue is blocked and does not accept publish or request messages from other threads. So you can do peacefully your work (your thread is allowed to modify the queue exclusively).

If you send messages during this method invocation they are queued only and are sent as soon as this method returns.

This method is invoked by the login polling thread from I_XmlBlasterAccess.

Specified by:

reachedAlive in interface I_ConnectionStateListener

Parameters:

oldState - The previous state of the connection.

See Also:

I_ConnectionStateListener.reachedAlive(org.xmlBlaster.util.dispatch.ConnectionStateEnum, org.xmlBlaster.client.I_XmlBlasterAccess)

reachedDead

public void reachedDead(ConnectionStateEnum oldState,
                        I_XmlBlasterAccess connection)

Description copied from interface: I_ConnectionStateListener

This is the callback method invoked from XmlBlasterAccess informing the client that the connection was lost (i.e. when the state of the connection has gone to DEAD).

Specified by:

reachedDead in interface I_ConnectionStateListener

Parameters:

oldState - The previous state of the connection.

reachedPolling

public void reachedPolling(ConnectionStateEnum oldState,
                           I_XmlBlasterAccess connection)

Description copied from interface: I_ConnectionStateListener

This is the callback method invoked from XmlBlasterAccess informing the client that the connection state has changed to POLLING.

Specified by:

reachedPolling in interface I_ConnectionStateListener

Parameters:

oldState - The previous state of the connection.