OpenJDK 1.22 · java.nio.channels.MembershipKey · APIdia, the JavaDoc alternative

A token representing the membership of an Internet Protocol (IP) multicast group.

A membership key may represent a membership to receive all datagrams sent to the group, or it may be source-specific, meaning that it represents a membership that receives only datagrams from a specific source address. Whether or not a membership key is source-specific may be determined by invoking its sourceAddress method.

A membership key is valid upon creation and remains valid until the membership is dropped by invoking the drop method, or the channel is closed. The validity of the membership key may be tested by invoking its isValid method.

Where a membership key is not source-specific and the underlying operation system supports source filtering, then the block and unblock methods can be used to block or unblock multicast datagrams from particular source addresses.

Access	Constructor and Description
protected	MembershipKey() Initializes a new instance of this class.

Method Summary

Modifier and Type	Method and Description
public abstract MembershipKey	Returns: This membership key block(InetAddress The source address to block source) Block multicast datagrams from the given source address.
public abstract MulticastChannel	Returns: the channel channel() Returns the channel for which this membership key was created.
public abstract void	drop() Drop membership.
public abstract InetAddress	Returns: the multicast group group() Returns the multicast group for which this membership key was created.
public abstract boolean	Returns: `true` if this membership key is valid, `false` otherwise isValid() Tells whether or not this membership is valid.
public abstract NetworkInterface	Returns: the network interface networkInterface() Returns the network interface for which this membership key was created.
public abstract InetAddress	Returns: The source address if this membership key is source-specific, otherwise `null` sourceAddress() Returns the source address if this membership key is source-specific, or `null` if this membership is not source-specific.
public abstract MembershipKey	Returns: This membership key unblock(InetAddress The source address to unblock source) Unblock multicast datagrams from the given source address that was previously blocked using the `block` method.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Constructor Detail

MembershipKey	back to summary
protected MembershipKey() Initializes a new instance of this class.

Method Detail

block back to summary

block	back to summary
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 datagrams from that source. This can arise when datagrams are waiting to be received in the socket's receive buffer. Parameters source:InetAddress The source address to block Returns:MembershipKey This membership key Exceptions IOException: If an I/O error occurs 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

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 datagrams from that source. This can arise when datagrams are waiting to be received in the socket's receive buffer.

Parameters

source:InetAddress: The source address to block

Returns:MembershipKey

This membership key

Exceptions

IOException:: If an I/O error occurs
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

channel back to summary

channel	back to summary
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:MulticastChannel the 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:MulticastChannel: the channel

drop back to summary

drop	back to summary
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.

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.

group back to summary

group	back to summary
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:InetAddress the multicast 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:InetAddress: the multicast group

isValid back to summary

isValid	back to summary
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:boolean `true` if this membership key is valid, `false` otherwise

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:boolean: true if this membership key is valid, false otherwise

networkInterface back to summary

networkInterface	back to summary
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:NetworkInterface the network interface

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:NetworkInterface: the network interface

sourceAddress back to summary

sourceAddress	back to summary
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:InetAddress The source address if this membership key is source-specific, otherwise `null`

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

unblock back to summary

unblock	back to summary
public abstract MembershipKey unblock(InetAddress source) Unblock multicast datagrams from the given source address that was previously blocked using the `block` method. Parameters source:InetAddress The source address to unblock Returns:MembershipKey This membership key Exceptions IllegalStateException: If the given source address is not currently blocked or the membership key is no longer valid

public abstract MembershipKey unblock(InetAddress source)

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