org.activemq.io
Class AbstractWireFormat

java.lang.Object
  org.activemq.io.AbstractWireFormat

All Implemented Interfaces:

WireFormat

Direct Known Subclasses:

AbstractDefaultWireFormat, JabberWireFormat, TextWireFormat

public abstract class AbstractWireFormat
extends Object
implements WireFormat

Represents a strategy of encoding packets on the wire or on disk using some kind of serialization or wire format.

We use a default efficient format for Java to Java communication but other formats to other systems can be used, such as using simple text strings when talking to JavaScript or coming up with other formats for talking to C / C# languages or proprietary messaging systems we wish to interface with at the wire level etc.

Version:

$Revision: 1.1.1.1 $

Field Summary

protected boolean	cachingEnabled
protected DataInputStream	transportDataIn
protected DataOutputStream	transportDataOut

Fields inherited from interface org.activemq.io.WireFormat

DEFAULT_MAXIMUM_MESSAGE_SIZE

Constructor Summary

AbstractWireFormat()

Method Summary

boolean	doesSupportMessageCompression() Some wire formats will not be able to understand compressed messages
boolean	doesSupportMessageFragmentation() some wire formats will implement their own fragementation
Packet	fromBytes(byte[] bytes) Reads the packet from the given byte[]
Packet	fromBytes(byte[] bytes, int offset, int length) Reads the packet from the given byte[]
DataInputStream	getTransportDataIn()
DataOutputStream	getTransportDataOut()
void	initiateClientSideProtocol() Some wire formats require a handshake at start-up
void	initiateServerSideProtocol() Some wire formats require a handshake at start-up
boolean	isCachingEnabled()
Packet	readPacket(DataInput dataIn) Reads a packet from the given input stream
Packet	readPacket(String channelID, DatagramPacket dpacket) Read a packet from a Datagram packet from the given channelID.
void	registerTransportStreams(DataOutputStream dataOut, DataInputStream dataIn) some transports may register their streams (e.g.
void	setCachingEnabled(boolean enableCaching)
void	setTransportDataIn(DataInputStream transportDataIn)
void	setTransportDataOut(DataOutputStream transportDataOut)
byte[]	toBytes(Packet packet) A helper method which converts a packet into a byte array
DatagramPacket	writePacket(String channelID, Packet packet) Writes the given package to a new datagram

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.activemq.io.WireFormat

canProcessWireFormatVersion, copy, getCurrentWireFormatVersion, readPacket, writePacket

Field Detail

transportDataOut

protected DataOutputStream transportDataOut

transportDataIn

protected DataInputStream transportDataIn

cachingEnabled

protected boolean cachingEnabled

Constructor Detail

AbstractWireFormat

public AbstractWireFormat()

Method Detail

readPacket

public Packet readPacket(String channelID,
                         DatagramPacket dpacket)
                  throws IOException

Read a packet from a Datagram packet from the given channelID. If the packet is from the same channel ID as it was sent then we have a loop-back so discard the packet

Specified by:

readPacket in interface WireFormat

Parameters:

channelID - is the unique channel ID

dpacket -

Returns:

the packet read from the datagram or null if it should be discarded

Throws:

IOException

writePacket

public DatagramPacket writePacket(String channelID,
                                  Packet packet)
                           throws IOException,
                                  JMSException

Writes the given package to a new datagram

Specified by:

writePacket in interface WireFormat

Parameters:

channelID - is the unique channel ID

packet - is the packet to write

Returns:

@throws IOException

Throws:

JMSException

IOException

fromBytes

public Packet fromBytes(byte[] bytes,
                        int offset,
                        int length)
                 throws IOException

Reads the packet from the given byte[]

Specified by:

fromBytes in interface WireFormat

Parameters:

bytes -

offset -

length -

Returns:

@throws IOException

Throws:

IOException

fromBytes

public Packet fromBytes(byte[] bytes)
                 throws IOException

Reads the packet from the given byte[]

Specified by:

fromBytes in interface WireFormat

Parameters:

bytes -

Returns:

@throws IOException

Throws:

IOException

toBytes

public byte[] toBytes(Packet packet)
               throws IOException,
                      JMSException

A helper method which converts a packet into a byte array

Specified by:

toBytes in interface WireFormat

Parameters:

packet -

Returns:

a byte array representing the packet using some wire protocol

Throws:

IOException

JMSException

registerTransportStreams

public void registerTransportStreams(DataOutputStream dataOut,
                                     DataInputStream dataIn)

some transports may register their streams (e.g. Tcp)

Specified by:

registerTransportStreams in interface WireFormat

Parameters:

dataOut -

dataIn -

initiateClientSideProtocol

public void initiateClientSideProtocol()
                                throws IOException

Some wire formats require a handshake at start-up

Specified by:

initiateClientSideProtocol in interface WireFormat

Throws:

IOException

initiateServerSideProtocol

public void initiateServerSideProtocol()
                                throws IOException

Some wire formats require a handshake at start-up

Specified by:

initiateServerSideProtocol in interface WireFormat

Throws:

IOException

isCachingEnabled

public boolean isCachingEnabled()

Specified by:

isCachingEnabled in interface WireFormat

Returns:

Returns the enableCaching.

setCachingEnabled

public void setCachingEnabled(boolean enableCaching)

Specified by:

setCachingEnabled in interface WireFormat

Parameters:

enableCaching - The enableCaching to set.

doesSupportMessageFragmentation

public boolean doesSupportMessageFragmentation()

some wire formats will implement their own fragementation

Specified by:

doesSupportMessageFragmentation in interface WireFormat

Returns:

true unless a wire format supports it's own fragmentation

doesSupportMessageCompression

public boolean doesSupportMessageCompression()

Some wire formats will not be able to understand compressed messages

Specified by:

doesSupportMessageCompression in interface WireFormat

Returns:

true unless a wire format cannot understand compression

getTransportDataOut

public DataOutputStream getTransportDataOut()

Returns:

Returns the transportDataOut.

setTransportDataOut

public void setTransportDataOut(DataOutputStream transportDataOut)

Parameters:

transportDataOut - The transportDataOut to set.

getTransportDataIn

public DataInputStream getTransportDataIn()

Returns:

Returns the transportDataIn.

setTransportDataIn

public void setTransportDataIn(DataInputStream transportDataIn)

Parameters:

transportDataIn - The transportDataIn to set.

readPacket

public Packet readPacket(DataInput dataIn)
                  throws IOException

Description copied from interface: WireFormat

Reads a packet from the given input stream

Specified by:

readPacket in interface WireFormat

Parameters:

dataIn -

Returns:

Throws:

IOException