# Uses of Class
java.nio.channels.MembershipKey

Packages that use MembershipKey
Package | Description
--- | ---
java.nio.channels | Defines channels, which represent connections to entities that are capable of performing I/O operations, such as files and sockets; defines selectors, for multiplexed, non-blocking I/O operations.

## Uses of MembershipKey in java.nio.channels

Methods in java.nio.channels that return MembershipKey
Modifier and Type | Method | Description
--- | --- | ---
`abstract MembershipKey` | MembershipKey.`block​(InetAddress source)` | Block multicast datagrams from the given source address.
`MembershipKey` | MulticastChannel.`join​(InetAddress group, NetworkInterface interf)` | Joins a multicast group to begin receiving all datagrams sent to the group, returning a membership key.
`MembershipKey` | MulticastChannel.`join​(InetAddress group, NetworkInterface interf, InetAddress source)` | Joins a multicast group to begin receiving datagrams sent to the group from a given source address.
`abstract MembershipKey` | MembershipKey.`unblock​(InetAddress source)` | Unblock multicast datagrams from the given source address that was previously blocked using the `block` method.