org.springframework.messaging

## Interface SubscribableChannel

- All Superinterfaces:
    MessageChannel
  All Known Implementing Classes:
    AbstractSubscribableChannel, ExecutorSubscribableChannel

      public interface SubscribableChannel
      extends MessageChannel

  A `MessageChannel` that maintains a registry of subscribers and invokes them to handle messages sent through this channel.
  Since:
    4.0
  Author:
    Mark Fisher

- - ### Field Summary

    - ### Fields inherited from interface org.springframework.messaging.MessageChannel

      `INDEFINITE_TIMEOUT`

  - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `boolean` | `subscribe(MessageHandler handler)` Register a message handler.
    `boolean` | `unsubscribe(MessageHandler handler)` Un-register a message handler.

    - ### Methods inherited from interface org.springframework.messaging.MessageChannel

      `send, send`

- - ### Method Detail

    - #### subscribe

          boolean subscribe(MessageHandler handler)

      Register a message handler.
      Returns:
        `true` if the handler was subscribed or `false` if it was already subscribed.

    - #### unsubscribe

          boolean unsubscribe(MessageHandler handler)

      Un-register a message handler.
      Returns:
        `true` if the handler was un-registered, or `false` if was not registered.