Package protocols.apps.chat

Class ChatPayload

java.lang.Object

protocols.apps.chat.ChatPayload

public final class ChatPayload
extends Object

The chat's own little "application protocol" that rides inside the broadcast's opaque byte[] payload. The broadcast layer doesn't know or care what these bytes mean — that's the whole point of layering: the broadcast moves bytes; the application decides what they are.

Two things travel by broadcast (i.e. to everyone):

• ChatPayload.Kind.TEXT — a message to the global channel (nick + text);
• ChatPayload.Kind.LEAVE — "I'm leaving" on a graceful /quit (nick).

Arrival and private messages go point-to-point instead — see ChatDirectMessage.

We hand-roll a tiny encoding with DataOutputStream (1 byte kind, then two length-prefixed UTF strings) so the wire format is obvious to a reader.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	ChatPayload.Kind

Constructor Summary

Constructors

Constructor	Description
ChatPayload(ChatPayload.Kind kind, String nick, String text)

Method Summary

Modifier and Type	Method	Description
static ChatPayload	decode(byte[] bytes)	Parse the bytes delivered by the broadcast layer back into a payload.
byte[]	encode()	Serialize to the bytes carried inside a broadcast message.
ChatPayload.Kind	getKind()
String	getNick()
String	getText()

Methods inherited from class java.lang.Object

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

Constructor Details

ChatPayload

public ChatPayload(ChatPayload.Kind kind,
 String nick,
 String text)

Method Details

getKind

public ChatPayload.Kind getKind()

getNick

public String getNick()

getText

public String getText()

encode

public byte[] encode()

Serialize to the bytes carried inside a broadcast message.

decode

public static ChatPayload decode(byte[] bytes)

Parse the bytes delivered by the broadcast layer back into a payload.