Class TFTPDataPacket


  • public final class TFTPDataPacket
    extends TFTPPacket
    A final class derived from TFTPPacket definiing the TFTP Data packet type.

    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:
    TFTPPacket, TFTPPacketException, TFTP
    • Constructor Summary

      Constructors 
      Constructor Description
      TFTPDataPacket​(java.net.DatagramPacket datagram)
      Creates a data packet based from a received datagram.
      TFTPDataPacket​(java.net.InetAddress destination, int port, int blockNumber, byte[] data)  
      TFTPDataPacket​(java.net.InetAddress destination, int port, int blockNumber, byte[] data, int offset, int length)
      Creates a data packet to be sent to a host at a given port with a given block number.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int getBlockNumber()
      Returns the block number of the data packet.
      byte[] getData()
      Returns the byte array containing the packet data.
      int getDataLength()
      Returns the length of the data part of the data packet.
      int getDataOffset()
      Returns the offset into the byte array where the packet data actually starts.
      java.net.DatagramPacket newDatagram()
      Creates a UDP datagram containing all the TFTP data packet data in the proper format.
      (package private) java.net.DatagramPacket newDatagram​(java.net.DatagramPacket datagram, byte[] data)
      This is a method only available within the package for implementing efficient datagram transport by elminating buffering.
      void setBlockNumber​(int blockNumber)
      Sets the block number of the data packet.
      void setData​(byte[] data, int offset, int length)
      Sets the data for the data packet.
      java.lang.String toString()
      For debugging
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Field Detail

      • MAX_DATA_LENGTH

        public static final int MAX_DATA_LENGTH
        The maximum number of bytes in a TFTP data packet (512)
        See Also:
        Constant Field Values
      • MIN_DATA_LENGTH

        public static final int MIN_DATA_LENGTH
        The minimum number of bytes in a TFTP data packet (0)
        See Also:
        Constant Field Values
      • blockNumber

        int blockNumber
        The block number of the packet.
      • length

        private int length
        The length of the data.
      • offset

        private int offset
        The offset into the _data array at which the data begins.
      • data

        private byte[] data
        The data stored in the packet.
    • Constructor Detail

      • TFTPDataPacket

        public TFTPDataPacket​(java.net.InetAddress destination,
                              int port,
                              int blockNumber,
                              byte[] data,
                              int offset,
                              int length)
        Creates a data packet to be sent to a host at a given port with a given block number. The actual data to be sent is passed as an array, an offset, and a length. The offset is the offset into the byte array where the data starts. The length is the length of the data. If the length is greater than MAX_DATA_LENGTH, it is truncated.
        Parameters:
        destination - The host to which the packet is going to be sent.
        port - The port to which the packet is going to be sent.
        blockNumber - The block number of the data.
        data - The byte array containing the data.
        offset - The offset into the array where the data starts.
        length - The length of the data.
      • TFTPDataPacket

        public TFTPDataPacket​(java.net.InetAddress destination,
                              int port,
                              int blockNumber,
                              byte[] data)
      • TFTPDataPacket

        TFTPDataPacket​(java.net.DatagramPacket datagram)
                throws TFTPPacketException
        Creates a data packet based from a received datagram. Assumes the datagram is at least length 4, else an ArrayIndexOutOfBoundsException may be thrown.
        Parameters:
        datagram - The datagram containing the received data.
        Throws:
        TFTPPacketException - If the datagram isn't a valid TFTP data packet.
    • Method Detail

      • newDatagram

        java.net.DatagramPacket newDatagram​(java.net.DatagramPacket datagram,
                                            byte[] data)
        This is a 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 is set as the datagram's data and the datagram returned.
        Specified by:
        newDatagram in class TFTPPacket
        Parameters:
        datagram - The datagram to create.
        data - The buffer to store the packet and to use in the datagram.
        Returns:
        The datagram argument.
      • newDatagram

        public java.net.DatagramPacket newDatagram()
        Creates a UDP datagram containing all the TFTP data packet data in the proper format. This is a 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.
        Specified by:
        newDatagram in class TFTPPacket
        Returns:
        A UDP datagram containing the TFTP data packet.
      • getBlockNumber

        public int getBlockNumber()
        Returns the block number of the data packet.
        Returns:
        The block number of the data packet.
      • setBlockNumber

        public void setBlockNumber​(int blockNumber)
        Sets the block number of the data packet.
        Parameters:
        blockNumber - the number to set
      • setData

        public void setData​(byte[] data,
                            int offset,
                            int length)
        Sets the data for the data packet.
        Parameters:
        data - The byte array containing the data.
        offset - The offset into the array where the data starts.
        length - The length of the data.
      • getDataLength

        public int getDataLength()
        Returns the length of the data part of the data packet.
        Returns:
        The length of the data part of the data packet.
      • getDataOffset

        public int getDataOffset()
        Returns the offset into the byte array where the packet data actually starts.
        Returns:
        The offset into the byte array where the packet data actually starts.
      • getData

        public byte[] getData()
        Returns the byte array containing the packet data.
        Returns:
        The byte array containing the packet data.
      • toString

        public java.lang.String toString()
        For debugging
        Overrides:
        toString in class TFTPPacket
        Since:
        3.6