Package org.apache.commons.net.tftp
Class TFTP
java.lang.Object
org.apache.commons.net.DatagramSocketClient
org.apache.commons.net.tftp.TFTP
- All Implemented Interfaces:
AutoCloseable
- Direct Known Subclasses:
TFTPClient
The TFTP class exposes a set of methods to allow you to deal with the TFTP protocol directly, in case you want to write your own TFTP client or server.
However, almost every user should only be concerend with the
open()
, and
close()
, methods. Additionally,the a
setDefaultTimeout()
method may be of importance for performance tuning.
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.
- See Also:
-
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final int
The ascii transfer mode.static final int
The binary transfer mode.static final int
The default TFTP port according to RFC 783 is 69.static final int
Deprecated.static final Duration
The default duration to wait to receive a datagram before timing out.static final int
The image transfer mode.static final int
The netascii transfer mode.static final int
The octet transfer mode.(package private) static final int
The size to use for TFTP packet buffers.private byte[]
A buffer used to accelerate receives in bufferedReceive()private DatagramPacket
A datagram used to minimize memory allocation in bufferedReceive()(package private) byte[]
A buffer used to accelerate sends in bufferedSend().private DatagramPacket
A datagram used to minimize memory allocation in bufferedSend()Fields inherited from class org.apache.commons.net.DatagramSocketClient
_isOpen_, _socket_, _socketFactory_, _timeout_
-
Constructor Summary
ConstructorsConstructorDescriptionTFTP()
Creates a TFTP instance with a default timeout ofDEFAULT_TIMEOUT_DURATION
, a null socket, and buffered operations disabled. -
Method Summary
Modifier and TypeMethodDescriptionfinal void
Initializes the internal buffers.final TFTPPacket
This is a special method to perform a more efficient packet receive.final void
bufferedSend
(TFTPPacket packet) This is a special method to perform a more efficient packet send.final void
This method synchronizes a connection by discarding all packets that may be in the local socket buffer.final void
Releases the resources used to perform buffered sends and receives.static final String
getModeName
(int mode) Returns the TFTP string representation of a TFTP transfer mode.final TFTPPacket
receive()
Receives a TFTPPacket.final void
send
(TFTPPacket packet) Sends a TFTP packet to its destination.protected void
trace
(String direction, TFTPPacket packet) Trace facility; this implementation does nothing.Methods inherited from class org.apache.commons.net.DatagramSocketClient
checkOpen, close, getCharset, getCharsetName, getDefaultTimeout, getLocalAddress, getLocalPort, getSoTimeout, getSoTimeoutDuration, isOpen, open, open, open, setCharset, setDatagramSocketFactory, setDefaultTimeout, setDefaultTimeout, setSoTimeout, setSoTimeout
-
Field Details
-
ASCII_MODE
public static final int ASCII_MODEThe ascii transfer mode. Its value is 0 and equivalent to NETASCII_MODE- See Also:
-
NETASCII_MODE
public static final int NETASCII_MODEThe netascii transfer mode. Its value is 0.- See Also:
-
BINARY_MODE
public static final int BINARY_MODEThe binary transfer mode. Its value is 1 and equivalent to OCTET_MODE.- See Also:
-
IMAGE_MODE
public static final int IMAGE_MODEThe image transfer mode. Its value is 1 and equivalent to OCTET_MODE.- See Also:
-
OCTET_MODE
public static final int OCTET_MODEThe octet transfer mode. Its value is 1.- See Also:
-
DEFAULT_TIMEOUT
Deprecated.The default number of milliseconds to wait to receive a datagram before timing out. The default is 5,000 milliseconds (5 seconds).- See Also:
-
DEFAULT_TIMEOUT_DURATION
The default duration to wait to receive a datagram before timing out. The default is 5 seconds.- Since:
- 3.10.0
-
DEFAULT_PORT
public static final int DEFAULT_PORTThe default TFTP port according to RFC 783 is 69.- See Also:
-
PACKET_SIZE
static final int PACKET_SIZEThe size to use for TFTP packet buffers. Its 4 plus the TFTPPacket.SEGMENT_SIZE, i.e. 516.- See Also:
-
receiveBuffer
private byte[] receiveBufferA buffer used to accelerate receives in bufferedReceive() -
receiveDatagram
A datagram used to minimize memory allocation in bufferedReceive() -
sendDatagram
A datagram used to minimize memory allocation in bufferedSend() -
sendBuffer
byte[] sendBufferA 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().
-
-
Constructor Details
-
TFTP
public TFTP()Creates a TFTP instance with a default timeout ofDEFAULT_TIMEOUT_DURATION
, a null socket, and buffered operations disabled.
-
-
Method Details
-
getModeName
Returns the TFTP string representation of a TFTP transfer mode. Will throw an ArrayIndexOutOfBoundsException if an invalid transfer mode is specified.- Parameters:
mode
- The TFTP transfer mode. One of the MODE constants.- Returns:
- The TFTP string representation of the TFTP transfer mode.
-
beginBufferedOps
public final void beginBufferedOps()Initializes the internal buffers. Buffers are used bybufferedSend()
andbufferedReceive()
. This method must be called before calling either one of those two methods. When you finish using buffered operations, you must callendBufferedOps()
. -
bufferedReceive
public final TFTPPacket bufferedReceive() throws IOException, InterruptedIOException, SocketException, TFTPPacketExceptionThis is a special method to perform a more efficient packet receive. It should only be used after callingbeginBufferedOps()
. 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 call.- Returns:
- The TFTPPacket received.
- Throws:
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.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.IOException
- If some other I/O error occurs.TFTPPacketException
- If an invalid TFTP packet is received.
-
bufferedSend
This is a special method to perform a more efficient packet send. It should only be used after callingbeginBufferedOps()
. 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 call.- Parameters:
packet
- The TFTP packet to send.- Throws:
IOException
- If some I/O error occurs.
-
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.- Throws:
IOException
- if an I/O error occurs.
-
endBufferedOps
public final void endBufferedOps()Releases the resources used to perform buffered sends and receives. -
receive
public final TFTPPacket receive() throws IOException, InterruptedIOException, SocketException, TFTPPacketExceptionReceives a TFTPPacket.- Returns:
- The TFTPPacket received.
- Throws:
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.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.IOException
- If some other I/O error occurs.TFTPPacketException
- If an invalid TFTP packet is received.
-
send
Sends a TFTP packet to its destination.- Parameters:
packet
- The TFTP packet to send.- Throws:
IOException
- If some I/O error occurs.
-
trace
Trace facility; this implementation does nothing.Override it to trace the data, for example:
System.out.println(direction + " " + packet.toString());
- Parameters:
direction
->
or<
packet
- the packet to be sent or that has been received respectively- Since:
- 3.6
-
DEFAULT_TIMEOUT_DURATION
.