Class TFTPDataPacket

java.lang.Object
org.apache.commons.net.tftp.TFTPPacket
org.apache.commons.net.tftp.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:
  • Field Details

    • MAX_DATA_LENGTH

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

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

      int _blockNumber
      The block number of the packet.
    • _length

      int _length
      The length of the data.
    • _offset

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

      byte[] _data
      The data stored in the packet.
  • Constructor Details

    • TFTPDataPacket

      public TFTPDataPacket(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(InetAddress destination, int port, int blockNumber, byte[] data)
    • TFTPDataPacket

      TFTPDataPacket(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 Details

    • _newDatagram

      DatagramPacket _newDatagram(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 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 String toString()
      For debugging
      Overrides:
      toString in class TFTPPacket
      Since:
      3.6