Class TFTPPacket

  • Direct Known Subclasses:
    TFTPAckPacket, TFTPDataPacket, TFTPErrorPacket, TFTPRequestPacket

    public abstract class TFTPPacket
    extends java.lang.Object
    TFTPPacket is an abstract class encapsulating the functionality common to the 5 types of TFTP packets. It also provides a static factory method that will create the correct TFTP packet instance from a datagram. This relieves the programmer from having to figure out what kind of TFTP packet is contained in a datagram and create it himself.

    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.

    Author:
    Daniel F. Savarese
    See Also:
    TFTPPacketException, TFTP
    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int ACKNOWLEDGEMENT
      Identifier returned by getType() indicating an acknowledgement packet.
      static int DATA
      Identifier returned by getType() indicating a data packet.
      static int ERROR
      Identifier returned by getType() indicating an error packet.
      static int READ_REQUEST
      Identifier returned by getType() indicating a read request packet.
      static int SEGMENT_SIZE
      The TFTP data packet maximum segment size in bytes.
      static int WRITE_REQUEST
      Identifier returned by getType() indicating a write request packet.
    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method Description
      java.net.InetAddress getAddress()
      Returns the address of the host where the packet is going to be sent or where it came from.
      int getPort()
      Returns the port where the packet is going to be sent or where it came from.
      int getType()
      Returns the type of the packet.
      abstract java.net.DatagramPacket newDatagram()
      This is an abstract method, exposed to the programmer in case he wants to implement his own TFTP client instead of using the TFTPClient class.
      static TFTPPacket newTFTPPacket​(java.net.DatagramPacket datagram)
      When you receive a datagram that you expect to be a TFTP packet, you use this factory method to create the proper TFTPPacket object encapsulating the data contained in that datagram.
      void setAddress​(java.net.InetAddress address)
      Sets the host address where the packet is going to be sent.
      void setPort​(int port)
      Sets the port where the packet is going to be sent.
      • Methods inherited from class java.lang.Object

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

      • READ_REQUEST

        public static final int READ_REQUEST
        Identifier returned by getType() indicating a read request packet. This is the actual TFTP spec identifier and is equal to 1.
        See Also:
        Constant Field Values
      • WRITE_REQUEST

        public static final int WRITE_REQUEST
        Identifier returned by getType() indicating a write request packet. This is the actual TFTP spec identifier and is equal to 2.
        See Also:
        Constant Field Values
      • DATA

        public static final int DATA
        Identifier returned by getType() indicating a data packet. This is the actual TFTP spec identifier and is equal to 3.
        See Also:
        Constant Field Values
      • ACKNOWLEDGEMENT

        public static final int ACKNOWLEDGEMENT
        Identifier returned by getType() indicating an acknowledgement packet. This is the actual TFTP spec identifier and is equal to 4.
        See Also:
        Constant Field Values
      • ERROR

        public static final int ERROR
        Identifier returned by getType() indicating an error packet. This is the actual TFTP spec identifier and is equal to 5.
        See Also:
        Constant Field Values
      • SEGMENT_SIZE

        public static final int SEGMENT_SIZE
        The TFTP data packet maximum segment size in bytes. This is 512 and is useful for those familiar with the TFTP protocol who want to use the TFTP class methods to implement their own TFTP servers or clients.
        See Also:
        Constant Field Values
    • Method Detail

      • newTFTPPacket

        public static final TFTPPacket newTFTPPacket​(java.net.DatagramPacket datagram)
                                              throws TFTPPacketException
        When you receive a datagram that you expect to be a TFTP packet, you use this factory method to create the proper TFTPPacket object encapsulating the data contained in that datagram. This method is the only way you can instantiate a TFTPPacket derived class from a datagram.

        Parameters:
        datagram - The datagram containing a TFTP packet.
        Returns:
        The TFTPPacket object corresponding to the datagram.
        Throws:
        TFTPPacketException - If the datagram does not contain a valid TFTP packet.
      • newDatagram

        public abstract java.net.DatagramPacket newDatagram()
        This is an abstract 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. It creates a UDP datagram containing all the TFTP packet data in the proper format.

        Returns:
        A UDP datagram containing the TFTP packet.
      • getType

        public final int getType()
        Returns the type of the packet.

        Returns:
        The type of the packet.
      • getAddress

        public final java.net.InetAddress getAddress()
        Returns the address of the host where the packet is going to be sent or where it came from.

        Returns:
        The type of the packet.
      • getPort

        public final int getPort()
        Returns the port where the packet is going to be sent or where it came from.

        Returns:
        The port where the packet came from or where it is going.
      • setPort

        public final void setPort​(int port)
        Sets the port where the packet is going to be sent.
      • setAddress

        public final void setAddress​(java.net.InetAddress address)
        Sets the host address where the packet is going to be sent.