org.apache.commons.net.tftp

Class TFTPAckPacket


public final class TFTPAckPacket
extends TFTPPacket

A final class derived from TFTPPacket definiing the TFTP Acknowledgement packet type.

Details regarding the TFTP protocol and the format of TFTP packets can be found in RFC 783. But the point of these classes is to keep you from having to worry about the internals. Additionally, only very few people should have to care about any of the TFTPPacket classes or derived classes. Almost all users should only be concerned with the TFTPClient class receiveFile() and sendFile() methods.

Author:
Daniel F. Savarese

See Also:
TFTPPacket, TFTPPacketException, TFTP

Field Summary

(package private) int
_blockNumber
The block number being acknowledged by the packet.

Fields inherited from class org.apache.commons.net.tftp.TFTPPacket

ACKNOWLEDGEMENT, DATA, ERROR, MIN_PACKET_SIZE, READ_REQUEST, SEGMENT_SIZE, WRITE_REQUEST, _address, _port, _type

Constructor Summary

TFTPAckPacket(DatagramPacket datagram)
Creates an acknowledgement packet based from a received datagram.
TFTPAckPacket(InetAddress destination, int port, int blockNumber)
Creates an acknowledgment packet to be sent to a host at a given port acknowledging receipt of a block.

Method Summary

(package private) DatagramPacket
_newDatagram(DatagramPacket datagram, byte[] data)
This is a method only available within the package for implementing efficient datagram transport by elminating buffering.
int
getBlockNumber()
Returns the block number of the acknowledgement.
DatagramPacket
newDatagram()
Creates a UDP datagram containing all the TFTP acknowledgement packet data in the proper format.
void
setBlockNumber(int blockNumber)
Sets the block number of the acknowledgement.

Methods inherited from class org.apache.commons.net.tftp.TFTPPacket

_newDatagram, getAddress, getPort, getType, newDatagram, newTFTPPacket, setAddress, setPort

Field Details

_blockNumber

(package private)  int _blockNumber
The block number being acknowledged by the packet. **

Constructor Details

TFTPAckPacket

(package private)  TFTPAckPacket(DatagramPacket datagram)
            throws TFTPPacketException
Creates an acknowledgement packet based from a received datagram. Assumes the datagram is at least length 4, else an ArrayIndexOutOfBoundsException may be thrown.

Parameters:
datagram - The datagram containing the received acknowledgement.

Throws:
TFTPPacketException - If the datagram isn't a valid TFTP acknowledgement packet.


TFTPAckPacket

public TFTPAckPacket(InetAddress destination,
                     int port,
                     int blockNumber)
Creates an acknowledgment packet to be sent to a host at a given port acknowledging receipt of a block.

Parameters:
destination - The host to which the packet is going to be sent.
port - The port to which the packet is going to be sent.
blockNumber - The block number being acknowledged.

Method Details

_newDatagram

(package private)  DatagramPacket _newDatagram(DatagramPacket datagram,
                                               byte[] data)
This is a method only available within the package for implementing efficient datagram transport by elminating buffering. It takes a datagram as an argument, and a byte buffer in which to store the raw datagram data. Inside the method, the data is set as the datagram's data and the datagram returned.

Overrides:
_newDatagram in interface TFTPPacket

Parameters:
datagram - The datagram to create.
data - The buffer to store the packet and to use in the datagram.

Returns:
The datagram argument.


getBlockNumber

public int getBlockNumber()
Returns the block number of the acknowledgement.

Returns:
The block number of the acknowledgement.


newDatagram

public DatagramPacket newDatagram()
Overrides:
newDatagram in interface TFTPPacket

Returns:
A UDP datagram containing the TFTP acknowledgement packet.


setBlockNumber

public void setBlockNumber(int blockNumber)
Sets the block number of the acknowledgement. **