rcx.josx.rcxcomm
Class LNP

java.lang.Object
  java.lang.Thread
      rcx.josx.rcxcomm.LNP

All Implemented Interfaces:

java.lang.Runnable

public class LNP
extends java.lang.Thread

An interface for sending and receiving Lego Network Protocol addressing and integrity layer packets. It uses an integrity packet handler to send and receive integrity and addressing packet. Listeners can be registered to process incoming broadcasts of integrity packets or addressing packets on multiple ports. Currently assumes that the most significant nibble of the address byte is the machine and the least significant nibble is the port number. The machine addresses is defined by the startListening call, but is also part of the source address sent with addressing packets.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Method Summary

static void	addAddressingHandler(AddressingHandler handler, byte port) Register an integrity handler to process incoming addressing packets for a specific port.
static void	addIntegrityHandler(IntegrityHandler handler) Register an integrity handler to process incoming broadcasts
static boolean	addressingWrite(byte[] packet, int len, byte dest, byte source) Sends packet of up to 255 bytes to the destination address from the source address.
static boolean	integrityWrite(byte[] packet, int len) Broadcasts an integrity packet
void	run() Background thread to listen for incoming packets and call the appropriate listeners.
static void	startListening(byte addr) Start listening for incoming broadcasts and addressing packets.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

addressingWrite

public static boolean addressingWrite(byte[] packet,
                                      int len,
                                      byte dest,
                                      byte source)

Sends packet of up to 255 bytes to the destination address from the source address. The source address is used for replying to the packet.

Parameters:

packet - the packet to send

len - the length of the packet

dest - the destination machine and port

source - the source machine and address

Returns:

true for successful send, else false, e.g. for collision detection

integrityWrite

public static boolean integrityWrite(byte[] packet,
                                     int len)

Broadcasts an integrity packet

Parameters:

packet - the packet to broadcast

len - the length of the packet

Returns:

true if sucessful, else false e.g. for collision detected

addIntegrityHandler

public static void addIntegrityHandler(IntegrityHandler handler)

Register an integrity handler to process incoming broadcasts

Parameters:

handler - the integrity handler

addAddressingHandler

public static void addAddressingHandler(AddressingHandler handler,
                                        byte port)

Register an integrity handler to process incoming addressing packets for a specific port.

Parameters:

handler - the addressing handler

startListening

public static void startListening(byte addr)

Start listening for incoming broadcasts and addressing packets.

Parameters:

addr - the address of this machine. The least significant 4 bits should be zero.

run

public void run()

Background thread to listen for incoming packets and call the appropriate listeners.

Specified by:

run in interface java.lang.Runnable

Overrides:

run in class java.lang.Thread