Package org.springframework.messaging.support

Interface ExecutorChannelInterceptor

All Superinterfaces:

ChannelInterceptor

public interface ExecutorChannelInterceptor
extends ChannelInterceptor

An extension of ChannelInterceptor with callbacks to intercept the asynchronous sending of a Message to a specific subscriber through an Executor. Supported on MessageChannel implementations that can be configured with an Executor.

Since:

4.1

Author:

Rossen Stoyanchev

See Also:

• Message
• MessageChannel
• MessageHandler

Method Summary

Modifier and Type	Method	Description
default void	afterMessageHandled(Message<?> message, MessageChannel channel, MessageHandler handler, Exception ex)	Invoked inside the Runnable submitted to the Executor after calling the target MessageHandler regardless of the outcome (i.e.
default Message<?>	beforeHandle(Message<?> message, MessageChannel channel, MessageHandler handler)	Invoked inside the Runnable submitted to the Executor just before calling the target MessageHandler to handle the message.

Methods inherited from interface org.springframework.messaging.support.ChannelInterceptor

afterReceiveCompletion, afterSendCompletion, postReceive, postSend, preReceive, preSend

Method Details

beforeHandle

@Nullable
default Message<?> beforeHandle(Message<?> message,
 MessageChannel channel,
 MessageHandler handler)

Invoked inside the Runnable submitted to the Executor just before calling the target MessageHandler to handle the message. Allows for modification of the Message if necessary or when null is returned the MessageHandler is not invoked.

Parameters:

message - the message to be handled

channel - the channel on which the message was sent to

handler - the target handler to handle the message

Returns:

the input message, or a new instance, or null

afterMessageHandled

default void afterMessageHandled(Message<?> message,
 MessageChannel channel,
 MessageHandler handler,
 @Nullable
 Exception ex)

Invoked inside the Runnable submitted to the Executor after calling the target MessageHandler regardless of the outcome (i.e. Exception raised or not) thus allowing for proper resource cleanup.

Note that this will be invoked only if beforeHandle successfully completed and returned a Message, i.e. it did not return null.

Parameters:

message - the message handled

channel - the channel on which the message was sent to

handler - the target handler that handled the message

ex - any exception that may have been raised by the handler