org.softamis.net.exchange.udp
Class UDPCommunicationHelper<K extends java.io.Serializable,V extends java.io.Serializable>

java.lang.Object
  org.softamis.net.exchange.support.AbstractCommunicationHelper<byte[],K,V>
      org.softamis.net.exchange.udp.UDPCommunicationHelper<K,V>

Type Parameters:

K - type of keys used to identify registry items

V - type of values stored in the registry

All Implemented Interfaces:

CommunicationHelper<K,V>, MulticastListener

public class UDPCommunicationHelper<K extends java.io.Serializable,V extends java.io.Serializable>
extends AbstractCommunicationHelper<byte[],K,V>
implements MulticastListener

Implementation of CommunicationHelper that uses UDP multicast as underlying trasport mechanizm of network communications.

Author:

Andrew Sazonov

See Also:

RegistryEventProcessor

Field Summary

static java.lang.String	DEFAULT_GROUP_NAME Default multicast group.
static int	DEFAULT_PORT Default port used for multicasting
protected int	fDefaultPort Default port for datagram packets.
protected int	fDefaultTimeToLive Default time to live for datagram packets.
protected static org.apache.commons.logging.Log	fLog
protected Multicaster	fMulticaster Multicaster that is used to perfom UDP packets sending and receiving
protected boolean	fOwnMulticaster Internal flag that indicates whether multicaster was not assigned outside.

Fields inherited from class org.softamis.net.exchange.support.AbstractCommunicationHelper

fCommunicationProtocol, fDefaultGroupName, fDefaultMessageSignature, fOwnCommunicationProtocol, fRegistryEventsMulticaster

Fields inherited from interface org.softamis.net.exchange.CommunicationHelper

COMMAND_ITEM_INVALID, COMMAND_ITEM_REGISTERED, COMMAND_ITEM_REQUEST, COMMAND_ITEM_UNREGISTERED

Constructor Summary

UDPCommunicationHelper()

Method Summary

void	close() Closing helper and multicaster (if one was not set from outside)
void	dataReceived(MulticastDataEvent aEvent) Listens for incoming multicaster' events and calls AbstractCommunicationHelper.receiveData(D) for futher processing
int	getDefaultPort() Returns default port for datagram packets.
int	getDefaultTimeToLive() Returns default time to live for datagram packets.
Multicaster	getMulticaster() Returns multicaster that is used to perfom UDP packets sending and receiving
void	init() Method used for initialization of communication helper.
protected void	initMulticaster()
protected void	insureCommunicationProtocolAndMulticasterSet()
protected void	processUnexpectedMessage(byte aMessageType, ItemEntry<K,V> aEntry) Method that is used to handle messages with unexpected type.
protected void	sendData(byte[] aDataToSend) Sends newtorking notification with provided data by delegating data provided to multicaster.
void	setDefaultMessageSignature(java.lang.String aDefaultMessageSignature) Sets signature that will be set to CommunicationProtocol if one is created (and not specified explicitely)
void	setDefaultPort(int aDefaultPort) Sets default port for datagram packets.
void	setDefaultTimeToLive(int aDefaultTimeToLive) Sets default time to live for datagram packets.
void	setMulticaster(Multicaster aMulticaster) Sets multicaster that is used to perfom UDP packets sending and receiving.

Methods inherited from class org.softamis.net.exchange.support.AbstractCommunicationHelper

addRegistryEventProcessor, createEntryToReceiveData, dispatchCommunicationMessage, doSendItemInvalidNotification, doSendItemRegisteredNotification, doSendItemsRequestNotification, doSendItemUnRegisteredNotification, getCommunicationProtocol, getDefaultGroupName, getDefaultMessageSignature, processReceivedData, processServiceInvalid, processServiceRegistered, processServiceRequest, processServiceUnRegistered, receiveData, removeRegistryEventProcessor, sendItemInvalidNotification, sendItemRegisteredNotification, sendItemsRequestNotification, sendItemUnRegisteredNotification, setCommunicationProtocol, setDefaultGroupName

Methods inherited from class java.lang.Object

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

Field Detail

fLog

protected static final org.apache.commons.logging.Log fLog

fMulticaster

protected Multicaster fMulticaster

Multicaster that is used to perfom UDP packets sending and receiving

fDefaultTimeToLive

protected int fDefaultTimeToLive

Default time to live for datagram packets. Used for multicaster creation if one is not specified.

fDefaultPort

protected int fDefaultPort

Default port for datagram packets. Used for multicaster creation if one is not specified.

fOwnMulticaster

protected boolean fOwnMulticaster

Internal flag that indicates whether multicaster was not assigned outside.

DEFAULT_GROUP_NAME

public static final java.lang.String DEFAULT_GROUP_NAME

Default multicast group.

See Also:

Constant Field Values

DEFAULT_PORT

public static final int DEFAULT_PORT

Default port used for multicasting

See Also:

Constant Field Values

Constructor Detail

UDPCommunicationHelper

public UDPCommunicationHelper()

Method Detail

insureCommunicationProtocolAndMulticasterSet

protected void insureCommunicationProtocolAndMulticasterSet()
                                                     throws java.net.UnknownHostException

Throws:

java.net.UnknownHostException

setDefaultMessageSignature

public void setDefaultMessageSignature(java.lang.String aDefaultMessageSignature)

Sets signature that will be set to CommunicationProtocol if one is created (and not specified explicitely)

Specified by:

setDefaultMessageSignature in interface CommunicationHelper<K extends java.io.Serializable,V extends java.io.Serializable>

Overrides:

setDefaultMessageSignature in class AbstractCommunicationHelper<byte[],K extends java.io.Serializable,V extends java.io.Serializable>

Parameters:

aDefaultMessageSignature - signature that will be set to CommunicationProtocol if one is created (and not specified explicitely)

init

public void init()
          throws java.io.IOException

Method used for initialization of communication helper. This method SHOULD be called before actual usage of this class. If multicaster is not specified from outside, default multicaster will be created.

Specified by:

init in interface CommunicationHelper<K extends java.io.Serializable,V extends java.io.Serializable>

Throws:

java.io.IOException - if

initMulticaster

protected void initMulticaster()
                        throws java.io.IOException

Throws:

java.io.IOException

close

public void close()

Closing helper and multicaster (if one was not set from outside)

Specified by:

close in interface CommunicationHelper<K extends java.io.Serializable,V extends java.io.Serializable>

processUnexpectedMessage

protected void processUnexpectedMessage(byte aMessageType,
                                        ItemEntry<K,V> aEntry)

Description copied from class: AbstractCommunicationHelper

Method that is used to handle messages with unexpected type. Inherited classes may implement it to add processing of additional commands.

Specified by:

processUnexpectedMessage in class AbstractCommunicationHelper<byte[],K extends java.io.Serializable,V extends java.io.Serializable>

Parameters:

aMessageType - type of message

aEntry - entry obtained with message

sendData

protected void sendData(byte[] aDataToSend)

Sends newtorking notification with provided data by delegating data provided to multicaster.

Specified by:

sendData in class AbstractCommunicationHelper<byte[],K extends java.io.Serializable,V extends java.io.Serializable>

Parameters:

aDataToSend - data which should be sent

dataReceived

public void dataReceived(MulticastDataEvent aEvent)

Listens for incoming multicaster' events and calls AbstractCommunicationHelper.receiveData(D) for futher processing

Specified by:

dataReceived in interface MulticastListener

Parameters:

aEvent - event from multicaster

getMulticaster

public Multicaster getMulticaster()

Returns multicaster that is used to perfom UDP packets sending and receiving

Returns:

multicaster

setMulticaster

public void setMulticaster(Multicaster aMulticaster)

Sets multicaster that is used to perfom UDP packets sending and receiving. If multicaster is not set, default multicaster will be created.

Parameters:

aMulticaster - multicaster

setDefaultPort

public void setDefaultPort(int aDefaultPort)

Sets default port for datagram packets. Used for multicaster creation if one is not specified.

Parameters:

aDefaultPort - default port for datagram packets.

getDefaultTimeToLive

public int getDefaultTimeToLive()

Returns default time to live for datagram packets. Used for multicaster creation if one is not specified.

Returns:

default time to live for datagram packets.

setDefaultTimeToLive

public void setDefaultTimeToLive(int aDefaultTimeToLive)

Sets default time to live for datagram packets. Used for multicaster creation if one is not specified.

Parameters:

aDefaultTimeToLive - default time to live for datagram packets.

getDefaultPort

public int getDefaultPort()

Returns default port for datagram packets. Used for multicaster creation if one is not specified.

Returns:

default port for datagram packets.