## org.jgroups
Interface MessageListener

All Known Subinterfaces:
  ExtendedMessageListener, ExtendedReceiver, Receiver

All Known Implementing Classes:
  DistributedQueue, DistributedTree, Draw, ExtendedReceiverAdapter, MessageListenerAdapter, MyReceiver, NotificationBus, QuoteServer, ReceiverAdapter, RELAY.Receiver, RelayDemoRpc, ReplicatedHashMap, ReplicatedTree, ViewDemo, VotingAdapter, Whiteboard

    public interface MessageListener

Allows a listener to be notified when a message arrives. Contrary to the pull-style of channels, some building blocks (e.g., `PullPushAdapter`) provide an event-like, push-style message delivery model. In this case, the entity to be notified of message reception needs to provide a callback to be invoked whenever a message has been received. The MessageListener interface provides a method to do so.

Method Summary
`byte[]` `getState()` Answers the group state; e.g., when joining.
`void` `receive(Message msg)` Called when a message is received.
`void` `setState(byte[] state)` Sets the group state; e.g., when joining.

Method Detail

### receive

    void receive(Message msg)

  Called when a message is received.

  Parameters:
    `msg` -

### getState

    byte[] getState()

  Answers the group state; e.g., when joining.

  Returns:
    byte[]

### setState

    void setState(byte[] state)

  Sets the group state; e.g., when joining.

  Parameters:
    `state` -

Copyright © 1998-2009 Bela Ban / Red Hat. All Rights Reserved.