Class MembershipKey

Constructor Detail

• MembershipKey

  protected MembershipKey()

  Initializes a new instance of this class.

Method Detail

• isValid

  public abstract boolean isValid()

  Tells whether or not this membership is valid.

  A multicast group membership is valid upon creation and remains valid until the membership is dropped by invoking the drop method, or the channel is closed.

  Returns:

  true if this membership key is valid, false otherwise

• drop

  public abstract void drop()

  Drop membership.

  If the membership key represents a membership to receive all datagrams then the membership is dropped and the channel will no longer receive any datagrams sent to the group. If the membership key is source-specific then the channel will no longer receive datagrams sent to the group from that source address.

  After membership is dropped it may still be possible to receive datagrams sent to the group. This can arise when datagrams are waiting to be received in the socket's receive buffer. After membership is dropped then the channel may join the group again in which case a new membership key is returned.

  Upon return, this membership object will be invalid. If the multicast group membership is already invalid then invoking this method has no effect. Once a multicast group membership is invalid, it remains invalid forever.

• block

  public abstract MembershipKey block(InetAddress source)
                               throws IOException

  Block multicast datagrams from the given source address.

  If this membership key is not source-specific, and the underlying operating system supports source filtering, then this method blocks multicast datagrams from the given source address. If the given source address is already blocked then this method has no effect. After a source address is blocked it may still be possible to receive datagams from that source. This can arise when datagrams are waiting to be received in the socket's receive buffer.

  Parameters:

  source - The source address to block

  Returns:

  This membership key

  Throws:

  IllegalArgumentException - If the source parameter is not a unicast address or is not the same address type as the multicast group

  IllegalStateException - If this membership key is source-specific or is no longer valid

  UnsupportedOperationException - If the underlying operating system does not support source filtering

  IOException - If an I/O error occurs

• unblock

  public abstract MembershipKey unblock(InetAddress source)

  Unblock multicast datagrams from the given source address that was previously blocked using the block method.

  Parameters:

  source - The source address to unblock

  Returns:

  This membership key

  Throws:

  IllegalStateException - If the given source address is not currently blocked or the membership key is no longer valid

• channel

  public abstract MulticastChannel channel()

  Returns the channel for which this membership key was created. This method will continue to return the channel even after the membership becomes invalid.

  Returns:

  the channel

• group

  public abstract InetAddress group()

  Returns the multicast group for which this membership key was created. This method will continue to return the group even after the membership becomes invalid.

  Returns:

  the multicast group

• networkInterface

  public abstract NetworkInterface networkInterface()

  Returns the network interface for which this membership key was created. This method will continue to return the network interface even after the membership becomes invalid.

  Returns:

  the network interface

• sourceAddress

  public abstract InetAddress sourceAddress()

  Returns the source address if this membership key is source-specific, or null if this membership is not source-specific.

  Returns:

  The source address if this membership key is source-specific, otherwise null