# 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.