File	Doc	Category	Size	Date	Package
TFTPPacket.java	API Doc	Apache Commons NET 1.4.1 API	8065	Sat Dec 03 10:05:48 GMT 2005	org.apache.commons.net.tftp

TFTPPacket

• java.lang.Object

Fields Summary
static final int	MIN_PACKET_SIZE The minimum size of a packet. This is 4 bytes. It is enough to store the opcode and blocknumber or other required data depending on the packet type.
public static final int	READ_REQUEST This is the actual TFTP spec identifier and is equal to 1. Identifier returned by {@link #getType getType()} indicating a read request packet.
public static final int	WRITE_REQUEST This is the actual TFTP spec identifier and is equal to 2. Identifier returned by {@link #getType getType()} indicating a write request packet.
public static final int	DATA This is the actual TFTP spec identifier and is equal to 3. Identifier returned by {@link #getType getType()} indicating a data packet.
public static final int	ACKNOWLEDGEMENT This is the actual TFTP spec identifier and is equal to 4. Identifier returned by {@link #getType getType()} indicating an acknowledgement packet.
public static final int	ERROR This is the actual TFTP spec identifier and is equal to 5. Identifier returned by {@link #getType getType()} indicating an error packet.
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 {@link org.apache.commons.net.tftp.TFTP} class methods to implement their own TFTP servers or clients.
int	_type The type of packet.
int	_port The port the packet came from or is going to.
InetAddress	_address The host the packet is going to be sent or where it came from.

Constructors Summary
TFTPPacket(int type, InetAddress address, int port) This constructor is not visible outside of the package. It is used by subclasses within the package to initialize base data. param type The type of the packet. param address The host the packet came from or is going to be sent. param port The port the packet came from or is going to be sent. _type = type; _address = address; _port = port;

Methods Summary
abstract java.net.DatagramPacket	_newDatagram(java.net.DatagramPacket datagram, byte[] data) This is an abstract 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 should be set as the datagram's data and the datagram returned. param datagram The datagram to create. param data The buffer to store the packet and to use in the datagram. return The datagram argument.
public final java.net.InetAddress	getAddress() Returns the address of the host where the packet is going to be sent or where it came from. return The type of the packet. return _address;
public final int	getPort() Returns the port where the packet is going to be sent or where it came from. return The port where the packet came from or where it is going. return _port;
public final int	getType() Returns the type of the packet. return The type of the packet. return _type;
public abstract java.net.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 {@link org.apache.commons.net.tftp.TFTPClient} class. Under normal circumstances, you should not have a need to call this method. return A UDP datagram containing the TFTP packet.
public static final org.apache.commons.net.tftp.TFTPPacket	newTFTPPacket(java.net.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. This method is the only way you can instantiate a TFTPPacket derived class from a datagram. param datagram The datagram containing a TFTP packet. return The TFTPPacket object corresponding to the datagram. exception TFTPPacketException If the datagram does not contain a valid TFTP packet. byte[] data; TFTPPacket packet = null; if (datagram.getLength() < MIN_PACKET_SIZE) throw new TFTPPacketException( "Bad packet. Datagram data length is too short."); data = datagram.getData(); switch (data[1]) { case READ_REQUEST: packet = new TFTPReadRequestPacket(datagram); break; case WRITE_REQUEST: packet = new TFTPWriteRequestPacket(datagram); break; case DATA: packet = new TFTPDataPacket(datagram); break; case ACKNOWLEDGEMENT: packet = new TFTPAckPacket(datagram); break; case ERROR: packet = new TFTPErrorPacket(datagram); break; default: throw new TFTPPacketException( "Bad packet. Invalid TFTP operator code."); } return packet;
public final void	setAddress(java.net.InetAddress address) Sets the host address where the packet is going to be sent. _address = address;
public final void	setPort(int port) Sets the port where the packet is going to be sent. _port = port;