org.xmlBlaster.util.dispatch
Class DispatchConnection

java.lang.Object
  org.xmlBlaster.util.dispatch.DispatchConnection

All Implemented Interfaces:

I_Timeout

Direct Known Subclasses:

ClientDispatchConnection

public abstract class DispatchConnection

extends java.lang.Object

implements I_Timeout

Holding all necessary infos to establish a remote connection and check this connection.

    State chart of a single connection:

          +<--toAlive()----+
          |                |
    #########            ##########         ##########
   #         #          #          #       #          #
   #  ALIVE  #          # POLLING  #       #   DEAD   #
   #         #          #          #       #          #
    #########            ##########         ##########
      |   |                |    |             |    |
      |   +--toPolling()-->+    +--toDead()-->+    |
      |                                            |
      +-------------toDead()---------------------->+

 

Note that DispatchConnection can't recover from DEAD state you need to create a new instance if desired

Author:

xmlBlaster@marcelruff.info, michele@laghi.eu

Field Summary

protected AddressBase	address
protected DispatchConnectionsHandler	connectionsHandler
protected Global	glob
java.lang.String	ME
protected java.lang.String	myId For logging only
protected boolean	physicalConnectionOk
static java.lang.String	PING_THREAD_NAME
protected long	previousBytesRead
protected long	previousBytesWritten
protected int	retryCounter
protected boolean	serverAcceptsRequests Flag if the remote server is reachable but is not willing to process our requests (standby mode).
protected ConnectionStateEnum	state

Constructor Summary

DispatchConnection(Global glob, DispatchConnectionsHandler connectionsHandler, AddressBase address)
Our loadPlugin() and initialize() needs to be called next.

Method Summary

abstract void	connectLowlevel() Connect on protocol layer and try an initial low level ping.
abstract java.lang.String	doPing(java.lang.String data) Does the real ping to the remote server instance.
abstract void	doSend(MsgQueueEntry[] msgArr_, boolean isAsyncMode) Send the messages.
void	finalize()
protected abstract boolean	forcePingFailure()
AddressBase	getAddress()
abstract java.lang.String	getDriverName() A human readable name of the protocol plugin
abstract java.lang.String	getName()
ConnectionStateEnum	getState()
protected void	handleTransition(boolean byDispatchConnectionsHandler, java.lang.Throwable throwable)
void	initialize() Connects on protocol level to the server and tries a ping.
boolean	isAlive()
boolean	isDead()
boolean	isPolling()
boolean	isUndef()
abstract void	loadPlugin() The derived class should create an instance of the protocol driver.
java.lang.String	ping(java.lang.String data) Ping the remote server instance (callback of the client or xmlBlaster itself)
protected java.lang.String	ping(java.lang.String data, boolean byDispatchConnectionsHandler) Ping the xmlBlaster server or callback server of the client.
protected abstract void	reconnect() On reconnect polling try to establish the connection
abstract I_ProgressListener	registerProgressListener(I_ProgressListener listener) Should be overwritten by extending classes.
abstract void	resetConnection() Called on COMMUNICATION errors, reset protocol driver for reconnect polling
void	send(MsgQueueEntry[] msgArr, boolean isAsyncMode) Send the messages back to the client.
void	setAddress(AddressBase address)
void	shutdown() Stop all remote connections.
protected void	spanPingTimer(long timeout, boolean isPing)
void	timeout(java.lang.Object userData) We are notified to do the next ping or reconnect polling.
abstract java.lang.String	toXml(java.lang.String extraOffset) Dump state of this object into a XML ASCII string.

Methods inherited from class java.lang.Object

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

Field Detail

ME

public final java.lang.String ME

glob

protected final Global glob

PING_THREAD_NAME

public static final java.lang.String PING_THREAD_NAME

See Also:

Constant Field Values

connectionsHandler

protected DispatchConnectionsHandler connectionsHandler

myId

protected final java.lang.String myId

For logging only

address

protected AddressBase address

state

protected ConnectionStateEnum state

retryCounter

protected int retryCounter

serverAcceptsRequests

protected boolean serverAcceptsRequests

Flag if the remote server is reachable but is not willing to process our requests (standby mode). This flag is only evaluated in POLLING state

physicalConnectionOk

protected boolean physicalConnectionOk

previousBytesWritten

protected long previousBytesWritten

previousBytesRead

protected long previousBytesRead

Constructor Detail

DispatchConnection

public DispatchConnection(Global glob,
                          DispatchConnectionsHandler connectionsHandler,
                          AddressBase address)

Our loadPlugin() and initialize() needs to be called next.

Parameters:

connectionsHandler - The DevliveryConnectionsHandler witch i belong to

address - The address i shall connect to

Method Detail

setAddress

public void setAddress(AddressBase address)
                throws XmlBlasterException

Throws:

XmlBlasterException

getName

public abstract java.lang.String getName()

Returns:

A nice name for logging

initialize

public final void initialize()
                      throws XmlBlasterException

Connects on protocol level to the server and tries a ping. Needs to be called after construction

Calls connectLowLevel() which needs to be implemented by derived classes loadPlugin() needs to be called before.

Called by ClientDispatchConnectionsHandler or CbDispatchConnectionsHandler

Throws:

XmlBlasterException

finalize

public void finalize()

getAddress

public final AddressBase getAddress()

resetConnection

public abstract void resetConnection()

Called on COMMUNICATION errors, reset protocol driver for reconnect polling

loadPlugin

public abstract void loadPlugin()
                         throws XmlBlasterException

The derived class should create an instance of the protocol driver.

Throws:

XmlBlasterException

connectLowlevel

public abstract void connectLowlevel()
                              throws XmlBlasterException

Connect on protocol layer and try an initial low level ping.

Throws:

XmlBlasterException - with ErrorCode.COMMUNICATION* if server is not reachable or other exceptions on other errors

getDriverName

public abstract java.lang.String getDriverName()

A human readable name of the protocol plugin

doSend

public abstract void doSend(MsgQueueEntry[] msgArr_,
                            boolean isAsyncMode)
                     throws XmlBlasterException

Send the messages.

Parameters:

isAsyncMode - true if coming from queue

Throws:

XmlBlasterException

registerProgressListener

public abstract I_ProgressListener registerProgressListener(I_ProgressListener listener)

Should be overwritten by extending classes.

send

public void send(MsgQueueEntry[] msgArr,
                 boolean isAsyncMode)
          throws XmlBlasterException

Send the messages back to the client.

Parameters:

msgArr - Should be a copy of the original, since we export it which changes/encrypts the content

isAsyncMode - true if coming from queue

Returns:

The returned string from the client which is decrypted if necessary, for oneway updates it is null

Throws:

XmlBlasterException

doPing

public abstract java.lang.String doPing(java.lang.String data)
                                 throws XmlBlasterException

Does the real ping to the remote server instance.

Parameters:

data - QoS, never null

Returns:

ping return QoS, never null

Throws:

XmlBlasterException

See Also:

org.xmlBlaster.protocol.I_XmlBlaster#ping(String)

ping

public final java.lang.String ping(java.lang.String data)
                            throws XmlBlasterException

Ping the remote server instance (callback of the client or xmlBlaster itself)

Throws:

XmlBlasterException

ping

protected final java.lang.String ping(java.lang.String data,
                                      boolean byDispatchConnectionsHandler)
                               throws XmlBlasterException

Ping the xmlBlaster server or callback server of the client. Sets serverAcceptsRequests to false if the protocol reaches the remote server but this is in standby mode.

Parameters:

byDispatchConnectionsHandler - true if invoked by DispatchConnectionsHandler we can throw exceptions back. false: If invoked by our timer/ping thread, we need to notify the situation

Throws:

XmlBlasterException

reconnect

protected abstract void reconnect()
                           throws XmlBlasterException

On reconnect polling try to establish the connection

Throws:

XmlBlasterException

timeout

public final void timeout(java.lang.Object userData)

We are notified to do the next ping or reconnect polling.

When connected, we ping
When connection is lost, we do reconnect polling

Specified by:

timeout in interface I_Timeout

Parameters:

userData - You get bounced back your userData which you passed with Timeout.addTimeoutListener() here it is "poll" or null

spanPingTimer

protected void spanPingTimer(long timeout,
                             boolean isPing)
                      throws XmlBlasterException

Throws:

XmlBlasterException

handleTransition

protected final void handleTransition(boolean byDispatchConnectionsHandler,
                                      java.lang.Throwable throwable)
                               throws XmlBlasterException

Parameters:

byDispatchConnectionsHandler - true if invoked by DispatchConnectionsHandler, false if invoked by our timer/ping

Throws:

XmlBlasterException - If delivery failed

shutdown

public void shutdown()
              throws XmlBlasterException

Stop all remote connections.

Throws:

XmlBlasterException

getState

public final ConnectionStateEnum getState()

isUndef

public final boolean isUndef()

isAlive

public final boolean isAlive()

isPolling

public final boolean isPolling()

isDead

public final boolean isDead()

toXml

public abstract java.lang.String toXml(java.lang.String extraOffset)

Dump state of this object into a XML ASCII string.

Parameters:

extraOffset - indenting of tags for nice output

Returns:

internal state as an XML ASCII string

forcePingFailure

protected abstract boolean forcePingFailure()

Returns:

true if the implementation has to throw an exception in case the ping is invoked when there is an ongoing write or read operation on the same connection. Normally it shall give false on the callback and true on the client side. The client side shall give true because otherwise if such a situation arizes it will never go in polling and no reconnect will be triggered.