verinec.adaptation.snmp.tftpserver
Class Download

java.lang.Object
  verinec.adaptation.snmp.tftpserver.Download

public class Download
extends Object

Class responsible for managing the download process for TFTP service. We are the server, so this handles sending a file to a client.

Most of the source was taken from www.it.rit.edu/~netsyslb/vksf522/class_examples/Day09_TFTPServer/Download.pdf
I removed the gui part.

Version:

1.0

Author:

christoph.ehret at unifr.ch

Nested Class Summary

private class

Download.Listener Private class that listens on a socket to receive datagrams.

Field Summary

private long	bytesToSend # of bytes left to download.
private InetAddress	clientAddress the address of the server.
private int	clientPort port to contact server on (69 per default).
private DatagramPacket	dgram unparsed TFTP packet.
private static int	DOWNLOADING State: Currently downloading.
private static int	ENDINGDL State: Just finishing downloading.
private DataInputStream	fistream input stream for reading the downloaded file.
private String	fp
private byte[]	lastBlock last block sent.
private int	lastBlockNo block # of last block sent.
private DatagramPacket	lastPacket last packet sent (for resends).
private String	lastPacketDesc description of last packet sent (for logs).
private Download.Listener	listener socket listener for incoming packets.
private String	localDirName name of the local download directory.
private String	localName name of the file.
private Logger	logger debugging.
private DatagramSocket	socket socket used to communicate with server.
private int	state state of the download.
private TFTPPacket	tftp parsed packet.
private Timer	timer timer used for resends.
private int	timerCount number of times the timer has expired.
(package private) ActionListener	timerExpired

Constructor Summary

Download(DatagramPacket pkt, TFTPPacket tftp, String localDirName)
Creates a Download instance for downloading data

Method Summary

private void	doACK(TFTPPacket pkt)
private void	doERROR(TFTPPacket pkt)
private void	doRRQ()
private void	endDownload()
private void	processPacket(DatagramPacket pkt)
void	resendPacket() Resends last sent packet if an error occured with sending of data.
private void	sendError(int code)
private void	sendNextBlock()
private void	sendPacket(DatagramPacket pkt)

Methods inherited from class java.lang.Object

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

Field Detail

fp

private String fp

logger

private Logger logger

debugging.

state

private int state

state of the download.

DOWNLOADING

private static final int DOWNLOADING

State: Currently downloading.

See Also:

Constant Field Values

ENDINGDL

private static final int ENDINGDL

State: Just finishing downloading.

See Also:

Constant Field Values

dgram

private DatagramPacket dgram

unparsed TFTP packet.

tftp

private TFTPPacket tftp

parsed packet.

localDirName

private String localDirName

name of the local download directory.

localName

private String localName

name of the file.

clientAddress

private InetAddress clientAddress

the address of the server.

clientPort

private int clientPort

port to contact server on (69 per default).

fistream

private DataInputStream fistream

input stream for reading the downloaded file.

lastBlockNo

private int lastBlockNo

block # of last block sent.

lastBlock

private byte[] lastBlock

last block sent.

bytesToSend

private long bytesToSend

# of bytes left to download.

timer

private Timer timer

timer used for resends.

timerCount

private int timerCount

number of times the timer has expired.

lastPacket

private DatagramPacket lastPacket

last packet sent (for resends).

lastPacketDesc

private String lastPacketDesc

description of last packet sent (for logs).

socket

private DatagramSocket socket

socket used to communicate with server.

listener

private Download.Listener listener

socket listener for incoming packets.

timerExpired

ActionListener timerExpired

Constructor Detail

Download

public Download(DatagramPacket pkt,
                TFTPPacket tftp,
                String localDirName)

Creates a Download instance for downloading data

Parameters:

pkt - Unparsed TFTP packet

tftp - Parsed TFTP packet

localDirName - Local download directory

See Also:

TFTPPacket

Method Detail

sendNextBlock

private void sendNextBlock()

resendPacket

public void resendPacket()

Resends last sent packet if an error occured with sending of data.

sendError

private void sendError(int code)

sendPacket

private void sendPacket(DatagramPacket pkt)
                 throws IOException

Throws:

IOException

endDownload

private void endDownload()

processPacket

private void processPacket(DatagramPacket pkt)

doRRQ

private void doRRQ()

doACK

private void doACK(TFTPPacket pkt)

doERROR

private void doERROR(TFTPPacket pkt)