Class DatagramSocketImpl

Field Detail

• localPort

  protected int localPort

  The local port number.

• fd

  protected FileDescriptor fd

  The file descriptor object.

Constructor Detail

• DatagramSocketImpl

  public DatagramSocketImpl()

Method Detail

• create

  protected abstract void create()
                          throws SocketException

  Creates a datagram socket.

  Throws:

  SocketException - if there is an error in the underlying protocol, such as a TCP error.

• bind

  protected abstract void bind(int lport,
          InetAddress laddr)
                        throws SocketException

  Binds a datagram socket to a local port and address.

  Parameters:

  lport - the local port

  laddr - the local address

  Throws:

  SocketException - if there is an error in the underlying protocol, such as a TCP error.

• send

  protected abstract void send(DatagramPacket p)
                        throws IOException

  Sends a datagram packet. The packet contains the data and the destination address to send the packet to.

  Parameters:

  p - the packet to be sent.

  Throws:

  IOException - if an I/O exception occurs while sending the datagram packet.

  PortUnreachableException - may be thrown if the socket is connected to a currently unreachable destination. Note, there is no guarantee that the exception will be thrown.

• connect

  protected void connect(InetAddress address,
             int port)
                  throws SocketException

  Connects a datagram socket to a remote destination. This associates the remote address with the local socket so that datagrams may only be sent to this destination and received from this destination. This may be overridden to call a native system connect.

  If the remote destination to which the socket is connected does not exist, or is otherwise unreachable, and if an ICMP destination unreachable packet has been received for that address, then a subsequent call to send or receive may throw a PortUnreachableException. Note, there is no guarantee that the exception will be thrown.

  Parameters:

  address - the remote InetAddress to connect to

  port - the remote port number

  Throws:

  SocketException - may be thrown if the socket cannot be connected to the remote destination

  Since:

  1.4

• disconnect

  protected void disconnect()

  Disconnects a datagram socket from its remote destination.

  Since:

  1.4

• peek

  protected abstract int peek(InetAddress i)
                       throws IOException

  Peek at the packet to see who it is from. Updates the specified InetAddress to the address which the packet came from.

  Parameters:

  i - an InetAddress object

  Returns:

  the port number which the packet came from.

  Throws:

  IOException - if an I/O exception occurs

  PortUnreachableException - may be thrown if the socket is connected to a currently unreachable destination. Note, there is no guarantee that the exception will be thrown.

• peekData

  protected abstract int peekData(DatagramPacket p)
                           throws IOException

  Peek at the packet to see who it is from. The data is copied into the specified DatagramPacket. The data is returned, but not consumed, so that a subsequent peekData/receive operation will see the same data.

  Parameters:

  p - the Packet Received.

  Returns:

  the port number which the packet came from.

  Throws:

  IOException - if an I/O exception occurs

  PortUnreachableException - may be thrown if the socket is connected to a currently unreachable destination. Note, there is no guarantee that the exception will be thrown.

  Since:

  1.4

• receive

  protected abstract void receive(DatagramPacket p)
                           throws IOException

  Receive the datagram packet.

  Parameters:

  p - the Packet Received.

  Throws:

  IOException - if an I/O exception occurs while receiving the datagram packet.

  PortUnreachableException - may be thrown if the socket is connected to a currently unreachable destination. Note, there is no guarantee that the exception will be thrown.

• setTTL

  @Deprecated
  protected abstract void setTTL(byte ttl)
                          throws IOException

  Deprecated. use setTimeToLive instead.
  Set the TTL (time-to-live) option.

  Parameters:

  ttl - a byte specifying the TTL value

  Throws:

  IOException - if an I/O exception occurs while setting the time-to-live option.

  See Also:

  getTTL()

• getTTL

  @Deprecated
  protected abstract byte getTTL()
                          throws IOException

  Deprecated. use getTimeToLive instead.
  Retrieve the TTL (time-to-live) option.

  Returns:

  a byte representing the TTL value

  Throws:

  IOException - if an I/O exception occurs while retrieving the time-to-live option

  See Also:

  setTTL(byte)

• setTimeToLive

  protected abstract void setTimeToLive(int ttl)
                                 throws IOException

  Set the TTL (time-to-live) option.

  Parameters:

  ttl - an int specifying the time-to-live value

  Throws:

  IOException - if an I/O exception occurs while setting the time-to-live option.

  See Also:

  getTimeToLive()

• getTimeToLive

  protected abstract int getTimeToLive()
                                throws IOException

  Retrieve the TTL (time-to-live) option.

  Returns:

  an int representing the time-to-live value

  Throws:

  IOException - if an I/O exception occurs while retrieving the time-to-live option

  See Also:

  setTimeToLive(int)

• join

  protected abstract void join(InetAddress inetaddr)
                        throws IOException

  Join the multicast group.

  Parameters:

  inetaddr - multicast address to join.

  Throws:

  IOException - if an I/O exception occurs while joining the multicast group.

• leave

  protected abstract void leave(InetAddress inetaddr)
                         throws IOException

  Leave the multicast group.

  Parameters:

  inetaddr - multicast address to leave.

  Throws:

  IOException - if an I/O exception occurs while leaving the multicast group.

• joinGroup

  protected abstract void joinGroup(SocketAddress mcastaddr,
               NetworkInterface netIf)
                             throws IOException

  Join the multicast group.

  Parameters:

  mcastaddr - address to join.

  netIf - specifies the local interface to receive multicast datagram packets

  Throws:

  IOException - if an I/O exception occurs while joining the multicast group

  Since:

  1.4

• leaveGroup

  protected abstract void leaveGroup(SocketAddress mcastaddr,
                NetworkInterface netIf)
                              throws IOException

  Leave the multicast group.

  Parameters:

  mcastaddr - address to leave.

  netIf - specified the local interface to leave the group at

  Throws:

  IOException - if an I/O exception occurs while leaving the multicast group

  Since:

  1.4

• close

  protected abstract void close()

  Close the socket.

• getLocalPort

  protected int getLocalPort()

  Gets the local port.

  Returns:

  an int representing the local port value

• getFileDescriptor

  protected FileDescriptor getFileDescriptor()

  Gets the datagram socket file descriptor.

  Returns:

  a FileDescriptor object representing the datagram socket file descriptor