stella.net.gregor

Class CommunicationHandler

java.lang.Object

util.PropertyContainer

io.AbstractDriver

io.AbstractSocketDriver

stella.net.gregor.CommunicationHandler

All Implemented Interfaces:

Driver, StreamIODriver, Cloneable, ExitCleaning, Initializable, PropertySupplying

Direct Known Subclasses:

GetterSetter

public class CommunicationHandler
extends AbstractSocketDriver

This class handles the low-level communication for GREGOR in providing a method to initiate message output and allows registering of a single event listener (a call-back agent) which is notified on incoming messages. This class is similar to the GreCo layer in GRE_KIS-NOT-0013

See Also:

MessageListener

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	CommunicationHandler.ReceiverThread The reciever thread waits on the input line until data comes available.
private class	CommunicationHandler.SenderThread This thread performs the sending of a message.
static class	CommunicationHandler.Test This class connects to the DCP server as stated in the command line properties, tries to connects and sends a NOP command.

Field Summary

Fields

Modifier and Type	Field and Description
private static long	DEFRECEIVERWAIT Default check time for incoming transmissions.
private static long	DEFSENDERWAIT Default wake-up period for sender, defines max time to cancel.
private static int	DEFSOCKETPORT Default port for the DCP.
private MessageListener	ear The message listener registered to this handler.
private Thread	incoming This thread handles the receiving of messages.
static String	KEY_RECEIVERWAIT The wait period for a receiver to check its stream.
static String	KEY_SENDERWAIT The wait period for a sender to check its queue.
private Deque<Message>	outqueue This is the dequeue used on output, no input queue necessary.
private Thread	sender This is the thread that handles the output.

Fields inherited from class io.AbstractSocketDriver

KEY_CLOSETIMEOUT, KEY_SOCKETPORT, KEY_SOCKETSERVER, KEY_SOCKETTIMEOUT

Fields inherited from class io.AbstractDriver

KEY_DRIVERNAME

Fields inherited from class util.PropertyContainer

KEY_LISTSEPARATOR, KEY_MAPKEYVALUECHAR, KEY_MAPSEPARATOR

Fields inherited from interface util.PropertySupplying

CONFIG, KEY_CLASS

Constructor Summary

Constructors

Constructor and Description
CommunicationHandler(Map<String,String> prop) Low-level Communication is deferred to the parental class that provides access to an input and an output stream.

Method Summary

Modifier and Type	Method and Description
boolean	close() On close, we additionally.
void	init() On init, we initialize the output queue.
boolean	putMessage(Message m) We send a message by placing it into the outqueue and notifying the sender thread.
boolean	setMessageListener(MessageListener receive) Sets the single message listener, returns true if no one was registerd yet.
boolean	startTransmission() We start the sender and receiver threads after ensuring proper opening of the TCP connection.
void	stopTransmission() We stop transmission by canceling the sender and receiver thread.

Methods inherited from class io.AbstractSocketDriver

authenticate, exit, getInputStream, getOutputStream, getSocket, isOpen, open, setTimeout

Methods inherited from class io.AbstractDriver

createDriver, equals, getDriverName, hashCode

Methods inherited from class util.PropertyContainer

augment, augment, augment, augment, augment, clone, defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsEnums, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, initProperties, isNew, parseObject, parseObject, reload, reload, removeProperty, requires, rescanned, setObject, setProperties, setProperty, stringProperties, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface io.Driver

getDriverName

Field Detail

KEY_SENDERWAIT

public static final String KEY_SENDERWAIT

The wait period for a sender to check its queue. Can be long.

See Also:

Constant Field Values

KEY_RECEIVERWAIT

public static final String KEY_RECEIVERWAIT

The wait period for a receiver to check its stream. Should be short.

See Also:

Constant Field Values

DEFSENDERWAIT

private static final long DEFSENDERWAIT

Default wake-up period for sender, defines max time to cancel.

See Also:

Constant Field Values

DEFRECEIVERWAIT

private static final long DEFRECEIVERWAIT

Default check time for incoming transmissions.

See Also:

Constant Field Values

DEFSOCKETPORT

private static final int DEFSOCKETPORT

Default port for the DCP.

See Also:

Constant Field Values

ear

private MessageListener ear

The message listener registered to this handler.

outqueue

private Deque<Message> outqueue

This is the dequeue used on output, no input queue necessary.

sender

private Thread sender

This is the thread that handles the output. it waits on the outqueue.

incoming

private Thread incoming

This thread handles the receiving of messages.

Constructor Detail

CommunicationHandler

public CommunicationHandler(Map<String,String> prop)

Low-level Communication is deferred to the parental class that provides access to an input and an output stream.

Method Detail

init

public void init()

On init, we initialize the output queue. The sender and receiver thread are created and started not before start is called.

Specified by:

init in interface Initializable

Overrides:

init in class AbstractSocketDriver

setMessageListener

public boolean setMessageListener(MessageListener receive)

Sets the single message listener, returns true if no one was registerd yet.

startTransmission

public boolean startTransmission()
                          throws IOException

We start the sender and receiver threads after ensuring proper opening of the TCP connection.

Throws:

IOException

putMessage

public boolean putMessage(Message m)
                   throws IOException

We send a message by placing it into the outqueue and notifying the sender thread. If the message received is marked as urgent, we put it to the start of the queue, otherwise we add it at the end.
This method synchronizes on the outqueue before entering the message into the queue. It then notifies the sender thread via the outquere (sender wait on queue). The queue is within the main class to allow queue buildup even if the transmission has not been started.

Throws:

IOException

close

public boolean close()
              throws IOException

On close, we additionally. stop the transmission.

Specified by:

close in interface Driver

Overrides:

close in class AbstractSocketDriver

Returns:

True if clean-up was successful.

Throws:

IOException - Exception to throw on disconnection error

stopTransmission

public void stopTransmission()

We stop transmission by canceling the sender and receiver thread.