Package org.springframework.integration.channel.interceptor

Class ThreadStatePropagationChannelInterceptor<S>

java.lang.Object

org.springframework.integration.channel.interceptor.ThreadStatePropagationChannelInterceptor<S>

Type Parameters:

S - the propagated state object type.

All Implemented Interfaces:

ChannelInterceptor, ExecutorChannelInterceptor

Direct Known Subclasses:

ObservationPropagationChannelInterceptor

public abstract class ThreadStatePropagationChannelInterceptor<S>
extends Object
implements ExecutorChannelInterceptor

The ExecutorChannelInterceptor implementation responsible for the Thread (any?) state propagation from one message flow's thread to another through the MessageChannels involved in the flow.

The propagation is done from the preSend(Message, MessageChannel) implementation using some internal Message extension which keeps the message to send and the state to propagate.

The propagated state context extraction and population is done from the postReceive(org.springframework.messaging.Message<?>, org.springframework.messaging.MessageChannel) implementation for the PollableChannels, and from the beforeHandle(org.springframework.messaging.Message<?>, org.springframework.messaging.MessageChannel, org.springframework.messaging.MessageHandler) for the AbstractExecutorChannels and ExecutorSubscribableChannels

Important. Any further interceptor, which modifies the message to send (e.g. MessageBuilder.withPayload(...)...build()), may drop the state to propagate. Such kind of interceptors combination should be revised properly. In most cases the interceptors reordering is enough to overcome the issue.

Since:

4.2

Author:

Artem Bilan, Gary Russell

Constructor Summary

Constructors

Constructor	Description
ThreadStatePropagationChannelInterceptor()

Method Summary

Modifier and Type	Method	Description
final Message<?>	beforeHandle(Message<?> message, MessageChannel channel, MessageHandler handler)
protected abstract S	obtainPropagatingContext(Message<?> message, MessageChannel channel)
protected abstract void	populatePropagatedContext(S state, Message<?> message, MessageChannel channel)
final Message<?>	postReceive(Message<?> message, MessageChannel channel)
final Message<?>	preSend(Message<?> message, MessageChannel channel)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

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

afterReceiveCompletion, afterSendCompletion, postSend, preReceive

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

afterMessageHandled

Constructor Details

ThreadStatePropagationChannelInterceptor

public ThreadStatePropagationChannelInterceptor()

Method Details

preSend

public final Message<?> preSend(Message<?> message,
 MessageChannel channel)

Specified by:

preSend in interface ChannelInterceptor

postReceive

public final Message<?> postReceive(Message<?> message,
 MessageChannel channel)

Specified by:

postReceive in interface ChannelInterceptor

beforeHandle

public final Message<?> beforeHandle(Message<?> message,
 MessageChannel channel,
 MessageHandler handler)

Specified by:

beforeHandle in interface ExecutorChannelInterceptor

obtainPropagatingContext

@Nullable
protected abstract S obtainPropagatingContext(Message<?> message,
 MessageChannel channel)

populatePropagatedContext

protected abstract void populatePropagatedContext(@Nullable
 S state,
 Message<?> message,
 MessageChannel channel)