Package com.oroinc.net.tftp
Class TFTP
java.lang.Object
com.oroinc.net.DatagramSocketClient
com.oroinc.net.tftp.TFTP
- 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.
- Author:
- Daniel F. Savarese
- See Also:
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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
The default number of milliseconds 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.Fields inherited from class com.oroinc.net.DatagramSocketClient
_isOpen_, _socket_, _socketFactory_, _timeout_
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Constructor Summary
ConstructorsConstructorDescriptionTFTP()
Creates a TFTP instance with a default timeout of DEFAULT_TIMEOUT, a null socket, and buffered operations disabled. -
Method Summary
Modifier and TypeMethodDescriptionfinal void
Initializes the internal buffers used by bufferedSend() and bufferedReceive() .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.Methods inherited from class com.oroinc.net.DatagramSocketClient
close, getDefaultTimeout, getLocalAddress, getLocalPort, getSoTimeout, isOpen, open, open, open, setDatagramSocketFactory, setDefaultTimeout, setSoTimeout
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Field Details
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ASCII_MODE
public static final int ASCII_MODEThe ascii transfer mode. Its value is 0 and equivalent to NETASCII_MODE- See Also:
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NETASCII_MODE
public static final int NETASCII_MODEThe netascii transfer mode. Its value is 0.- See Also:
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BINARY_MODE
public static final int BINARY_MODEThe binary transfer mode. Its value is 1 and equivalent to OCTET_MODE.- See Also:
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IMAGE_MODE
public static final int IMAGE_MODEThe image transfer mode. Its value is 1 and equivalent to OCTET_MODE.- See Also:
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OCTET_MODE
public static final int OCTET_MODEThe octet transfer mode. Its value is 1.- See Also:
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DEFAULT_TIMEOUT
public static final int DEFAULT_TIMEOUTThe default number of milliseconds to wait to receive a datagram before timing out. The default is 5000 milliseconds (5 seconds).- See Also:
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DEFAULT_PORT
public static final int DEFAULT_PORTThe default TFTP port according to RFC 783 is 69.- See Also:
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Constructor Details
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TFTP
public TFTP()Creates a TFTP instance with a default timeout of DEFAULT_TIMEOUT, a null socket, and buffered operations disabled.
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Method Details
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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.
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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.
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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 calling 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.- 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.
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bufferedSend
This is a special method to perform a more efficient packet send. It should only be used after calling 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.- Parameters:
TFTPPacket
- The TFTP packet to send.- Throws:
IOException
- If some I/O error occurs.
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beginBufferedOps
public final void beginBufferedOps()Initializes the internal buffers used by bufferedSend() and bufferedReceive() . This method must be called before calling either one of those two methods. When you finish using buffered operations, you must call endBufferedOps() . -
endBufferedOps
public final void endBufferedOps()Releases the resources used to perform buffered sends and receives. -
send
Sends a TFTP packet to its destination.- Parameters:
TFTPPacket
- The TFTP packet to send.- Throws:
IOException
- If some I/O error occurs.
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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.
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