net.sf.juoserver.protocol
Class AbstractMessage

java.lang.Object
  net.sf.juoserver.protocol.AbstractMessage

All Implemented Interfaces:

Serializable, Message

Direct Known Subclasses:

CharacterDraw, CharacterList, CharacterSelect, CharacterWarmode, ClientFeatures, ClientVersion, ClilocMessage, DeleteItem, DoubleClick, DragItem, DrawContainer, DrawGamePlayer, DropItem, GeneralInformation, GetPlayerStatus, LoginComplete, LoginConfirm, LoginReject, LoginRequest, LoginSeed, LookRequest, MegaClilocRequest, MegaClilocResponse, MovementAck, MovementReject, MoveRequest, ObjectInfo, ObjectRevision, OverallLightLevel, Paperdoll, PersonalLightLevel, PickUpItem, PingPong, SeasonalInformation, SelectServer, ServerConnect, ServerList, ServerLoginRequest, SkillLock, SkillUpdate, SpyOnClient, StatusBarInfo, UnicodeSpeech, UnicodeSpeechRequest, UpdatePlayer, WearItem

public abstract class AbstractMessage
extends Object
implements Message, Serializable

Base class for messages.

Messages can be sent by the client or the server, or both (e.g. ClientVersion).

Messages sent by clients (e.g. CharacterSelect) should:

• Be annotated with Decodable,
• Provide a public constructor taking a single byte array.

Messages sent by the server (e.g. CharacterList) should:

• Override the encode() method,
• Possibly override the isCompressed() method.

By creating a client message by following the above steps, the server is already able to receive that message.

It is however also necessary to provide the ability to process that client message, by adding a handler to the ControllerImpl class and thus letting it reply to the client message with a server message.

See Also:

Serialized Form

Field Summary

protected static int	NO_CODE
static String	UTF8

Constructor Summary

protected

AbstractMessage(int code, int length) Builds a message from the code that identifies it.

Method Summary

ByteBuffer	encode() Encodes this message into a byte array packet.
abstract boolean	equals(Object obj)
int	getCode()
int	getLength()
String	getName()
abstract int	hashCode()
boolean	isCompressed() Default value is true.
protected ByteBuffer	wrapContents(byte[] contents) Returns a new ByteBuffer wrapping the packet contents, excluding the first byte (the packet code).
protected ByteBuffer	wrapContents(int fromIndexInclusive, byte[] contents) Returns a new ByteBuffer wrapping the packet contents, starting from the specified index, inclusive.

Methods inherited from class java.lang.Object

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

Field Detail

UTF8

public static final String UTF8

See Also:

Constant Field Values

NO_CODE

protected static final int NO_CODE

See Also:

Constant Field Values

Constructor Detail

AbstractMessage

protected AbstractMessage(int code,
                          int length)

Builds a message from the code that identifies it. This code is the first byte in the message packet.

Parameters:

code - message's identification code

Method Detail

encode

public ByteBuffer encode()

Description copied from interface: Message

Encodes this message into a byte array packet.

The array is wrapped in a byte buffer in order to let subclasses append their contents.

Specified by:

encode in interface Message

Returns:

the byte array representation (a.k.a. packet) of this message

isCompressed

public boolean isCompressed()

Default value is true.

Specified by:

isCompressed in interface Message

Returns:

true if and only if this message should be compressed when sent by the server

getCode

public final int getCode()

Specified by:

getCode in interface Message

Returns:

this message's code

getLength

public final int getLength()

Specified by:

getLength in interface Message

Returns:

this message's length in bytes

hashCode

public abstract int hashCode()

Overrides:

hashCode in class Object

equals

public abstract boolean equals(Object obj)

Overrides:

equals in class Object

getName

public final String getName()

Returns:

this message's name

wrapContents

protected final ByteBuffer wrapContents(byte[] contents)

Returns a new ByteBuffer wrapping the packet contents, excluding the first byte (the packet code).

Note that the returned buffer will be backed up by the provided array, therefore modifications to the buffer will change the array and vice versa.

Parameters:

contents - packet contents

Returns:

a new ByteBuffer wrapping the packet contents, excluding the first byte (the packet code)

See Also:

wrapContents(int, byte[])

wrapContents

protected final ByteBuffer wrapContents(int fromIndexInclusive,
                                        byte[] contents)

Returns a new ByteBuffer wrapping the packet contents, starting from the specified index, inclusive.

Note that the returned buffer will be backed up by the provided array, therefore modifications to the buffer will change the array and vice versa.

Parameters:

fromIndexInclusive - starting index where to start reading the contents, inclusive

contents - packet contents

Returns:

a new ByteBuffer wrapping the packet contents, excluding the first byte (the packet code)

See Also:

ByteBuffer.wrap(byte[], int, int)