File	Doc	Category	Size	Date	Package
TFTP.java	API Doc	Apache Commons NET 1.4.1 API	11079	Sat Dec 03 10:05:48 GMT 2005	org.apache.commons.net.tftp

TFTP

• java.lang.Object
  • org.apache.commons.net.DatagramSocketClient

Fields Summary
public static final int	ASCII_MODE The ascii transfer mode. Its value is 0 and equivalent to NETASCII_MODE
public static final int	NETASCII_MODE The netascii transfer mode. Its value is 0.
public static final int	BINARY_MODE The binary transfer mode. Its value is 1 and equivalent to OCTET_MODE.
public static final int	IMAGE_MODE The image transfer mode. Its value is 1 and equivalent to OCTET_MODE.
public static final int	OCTET_MODE The octet transfer mode. Its value is 1.
public static final int	DEFAULT_TIMEOUT The default number of milliseconds to wait to receive a datagram before timing out. The default is 5000 milliseconds (5 seconds).
public static final int	DEFAULT_PORT The default TFTP port according to RFC 783 is 69.
static final int	PACKET_SIZE The size to use for TFTP packet buffers. Its 4 plus the TFTPPacket.SEGMENT_SIZE, i.e. 516.
private byte[]	__receiveBuffer A buffer used to accelerate receives in bufferedReceive()
private DatagramPacket	__receiveDatagram A datagram used to minimize memory allocation in bufferedReceive()
private DatagramPacket	__sendDatagram A datagram used to minimize memory allocation in bufferedSend()
byte[]	_sendBuffer A buffer used to accelerate sends in bufferedSend(). It is left package visible so that TFTPClient may be slightly more efficient during file sends. It saves the creation of an additional buffer and prevents a buffer copy in _newDataPcket().

Constructors Summary
public TFTP() Creates a TFTP instance with a default timeout of DEFAULT_TIMEOUT, a null socket, and buffered operations disabled. setDefaultTimeout(DEFAULT_TIMEOUT); __receiveBuffer = null; __receiveDatagram = null;

Methods Summary
public final void	beginBufferedOps() Initializes the internal buffers. Buffers are used by {@link #bufferedSend bufferedSend() } and {@link #bufferedReceive bufferedReceive() }. This method must be called before calling either one of those two methods. When you finish using buffered operations, you must call {@link #endBufferedOps endBufferedOps() }. __receiveBuffer = new byte[PACKET_SIZE]; __receiveDatagram = new DatagramPacket(__receiveBuffer, __receiveBuffer.length); _sendBuffer = new byte[PACKET_SIZE]; __sendDatagram = new DatagramPacket(_sendBuffer, _sendBuffer.length);
public final TFTPPacket	bufferedReceive() This is a special method to perform a more efficient packet receive. It should only be used after calling {@link #beginBufferedOps beginBufferedOps() }. beginBufferedOps() initializes a set of buffers used internally that prevent the new allocation of a DatagramPacket and byte array for each send and receive. To use these buffers you must call the bufferedReceive() and bufferedSend() methods instead of send() and receive(). You must also be certain that you don't manipulate the resulting packet in such a way that it interferes with future buffered operations. For example, a TFTPDataPacket received with bufferedReceive() will have a reference to the internal byte buffer. You must finish using this data before calling bufferedReceive() again, or else the data will be overwritten by the the call. return The TFTPPacket received. exception InterruptedIOException If a socket timeout occurs. The Java documentation claims an InterruptedIOException is thrown on a DatagramSocket timeout, but in practice we find a SocketException is thrown. You should catch both to be safe. exception SocketException If a socket timeout occurs. The Java documentation claims an InterruptedIOException is thrown on a DatagramSocket timeout, but in practice we find a SocketException is thrown. You should catch both to be safe. exception IOException If some other I/O error occurs. exception TFTPPacketException If an invalid TFTP packet is received. __receiveDatagram.setData(__receiveBuffer); __receiveDatagram.setLength(__receiveBuffer.length); _socket_.receive(__receiveDatagram); return TFTPPacket.newTFTPPacket(__receiveDatagram);
public final void	bufferedSend(TFTPPacket packet) This is a special method to perform a more efficient packet send. It should only be used after calling {@link #beginBufferedOps beginBufferedOps() }. beginBufferedOps() initializes a set of buffers used internally that prevent the new allocation of a DatagramPacket and byte array for each send and receive. To use these buffers you must call the bufferedReceive() and bufferedSend() methods instead of send() and receive(). You must also be certain that you don't manipulate the resulting packet in such a way that it interferes with future buffered operations. For example, a TFTPDataPacket received with bufferedReceive() will have a reference to the internal byte buffer. You must finish using this data before calling bufferedReceive() again, or else the data will be overwritten by the the call. param packet The TFTP packet to send. exception IOException If some I/O error occurs. _socket_.send(packet._newDatagram(__sendDatagram, _sendBuffer));
public final void	discardPackets() This method synchronizes a connection by discarding all packets that may be in the local socket buffer. This method need only be called when you implement your own TFTP client or server. exception IOException if an I/O error occurs. int to; DatagramPacket datagram; datagram = new DatagramPacket(new byte[PACKET_SIZE], PACKET_SIZE); to = getSoTimeout(); setSoTimeout(1); try { while (true) _socket_.receive(datagram); } catch (SocketException e) { // Do nothing. We timed out so we hope we're caught up. } catch (InterruptedIOException e) { // Do nothing. We timed out so we hope we're caught up. } setSoTimeout(to);
public final void	endBufferedOps() Releases the resources used to perform buffered sends and receives. __receiveBuffer = null; __receiveDatagram = null; _sendBuffer = null; __sendDatagram = null;
public static final java.lang.String	getModeName(int mode) Returns the TFTP string representation of a TFTP transfer mode. Will throw an ArrayIndexOutOfBoundsException if an invalid transfer mode is specified. param mode The TFTP transfer mode. One of the MODE constants. return The TFTP string representation of the TFTP transfer mode. return TFTPRequestPacket._modeStrings[mode];
public final TFTPPacket	receive() Receives a TFTPPacket. return The TFTPPacket received. exception InterruptedIOException If a socket timeout occurs. The Java documentation claims an InterruptedIOException is thrown on a DatagramSocket timeout, but in practice we find a SocketException is thrown. You should catch both to be safe. exception SocketException If a socket timeout occurs. The Java documentation claims an InterruptedIOException is thrown on a DatagramSocket timeout, but in practice we find a SocketException is thrown. You should catch both to be safe. exception IOException If some other I/O error occurs. exception TFTPPacketException If an invalid TFTP packet is received. DatagramPacket packet; packet = new DatagramPacket(new byte[PACKET_SIZE], PACKET_SIZE); _socket_.receive(packet); return TFTPPacket.newTFTPPacket(packet);
public final void	send(TFTPPacket packet) Sends a TFTP packet to its destination. param packet The TFTP packet to send. exception IOException If some I/O error occurs. _socket_.send(packet.newDatagram());