Package org.apache.commons.net.tftp

Class TFTPPacket

java.lang.Object

org.apache.commons.net.tftp.TFTPPacket

Direct Known Subclasses:

TFTPAckPacket, TFTPDataPacket, TFTPErrorPacket, TFTPRequestPacket

public abstract class TFTPPacket
extends Object

TFTPPacket is an abstract class encapsulating the functionality common to the 5 types of TFTP packets. It also provides a static factory method that will create the correct TFTP packet instance from a datagram. This relieves the programmer from having to figure out what kind of TFTP packet is contained in a datagram and create it himself.

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.

See Also:

• TFTPPacketException
• TFTP

Field Summary

Fields

Modifier and Type	Field	Description
static final int	ACKNOWLEDGEMENT	This is the actual TFTP spec identifier and is equal to 4.
static final int	DATA	This is the actual TFTP spec identifier and is equal to 3.
static final int	ERROR	This is the actual TFTP spec identifier and is equal to 5.
static final int	READ_REQUEST	This is the actual TFTP spec identifier and is equal to 1.
static final int	SEGMENT_SIZE	The TFTP data packet maximum segment size in bytes.
static final int	WRITE_REQUEST	This is the actual TFTP spec identifier and is equal to 2.

Method Summary

Modifier and Type	Method	Description
final InetAddress	getAddress()	Returns the address of the host where the packet is going to be sent or where it came from.
final int	getPort()	Returns the port where the packet is going to be sent or where it came from.
final int	getType()	Returns the type of the packet.
abstract DatagramPacket	newDatagram()	Creates a UDP datagram containing all the TFTP packet data in the proper format.
static final TFTPPacket	newTFTPPacket(DatagramPacket datagram)	When you receive a datagram that you expect to be a TFTP packet, you use this factory method to create the proper TFTPPacket object encapsulating the data contained in that datagram.
final void	setAddress(InetAddress address)	Sets the host address where the packet is going to be sent.
final void	setPort(int port)	Sets the port where the packet is going to be sent.
String	toString()	For debugging

Methods inherited from class java.lang.Object

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

Field Details

READ_REQUEST

public static final int READ_REQUEST

This is the actual TFTP spec identifier and is equal to 1. Identifier returned by getType() indicating a read request packet.

See Also:

• Constant Field Values

WRITE_REQUEST

public static final int WRITE_REQUEST

This is the actual TFTP spec identifier and is equal to 2. Identifier returned by getType() indicating a write request packet.

See Also:

• Constant Field Values

DATA

public static final int DATA

This is the actual TFTP spec identifier and is equal to 3. Identifier returned by getType() indicating a data packet.

See Also:

• Constant Field Values

ACKNOWLEDGEMENT

public static final int ACKNOWLEDGEMENT

This is the actual TFTP spec identifier and is equal to 4. Identifier returned by getType() indicating an acknowledgement packet.

See Also:

• Constant Field Values

ERROR

public static final int ERROR

This is the actual TFTP spec identifier and is equal to 5. Identifier returned by getType() indicating an error packet.

See Also:

• Constant Field Values

SEGMENT_SIZE

public static final int SEGMENT_SIZE

The TFTP data packet maximum segment size in bytes. This is 512 and is useful for those familiar with the TFTP protocol who want to use the TFTP class methods to implement their own TFTP servers or clients.

See Also:

• Constant Field Values

Method Details

newTFTPPacket

public static final TFTPPacket newTFTPPacket(DatagramPacket datagram)
                                      throws TFTPPacketException

When you receive a datagram that you expect to be a TFTP packet, you use this factory method to create the proper TFTPPacket object encapsulating the data contained in that datagram. This method is the only way you can instantiate a TFTPPacket derived class from a datagram.

Parameters:

datagram - The datagram containing a TFTP packet.

Returns:

The TFTPPacket object corresponding to the datagram.

Throws:

TFTPPacketException - If the datagram does not contain a valid TFTP packet.

getAddress

public final InetAddress getAddress()

Returns the address of the host where the packet is going to be sent or where it came from.

Returns:

The type of the packet.

getPort

public final int getPort()

Returns the port where the packet is going to be sent or where it came from.

Returns:

The port where the packet came from or where it is going.

getType

public final int getType()

Returns the type of the packet.

Returns:

The type of the packet.

newDatagram

public abstract DatagramPacket newDatagram()

Creates a UDP datagram containing all the TFTP packet data in the proper format. This is an abstract method, exposed to the programmer in case he wants to implement his own TFTP client instead of using the TFTPClient class. Under normal circumstances, you should not have a need to call this method.

Returns:

A UDP datagram containing the TFTP packet.

setAddress

public final void setAddress(InetAddress address)

Sets the host address where the packet is going to be sent.

Parameters:

address - the address to set

setPort

public final void setPort(int port)

Sets the port where the packet is going to be sent.

Parameters:

port - the port to set

toString

public String toString()

For debugging

Overrides:

toString in class Object

Since:

3.6