Package org.axonframework.messaging.commandhandling.interception

Class CommandSequencingInterceptor<M extends CommandMessage>

java.lang.Object

org.axonframework.messaging.commandhandling.interception.CommandSequencingInterceptor<M>

Type Parameters:

M - the Message type this interceptor can process

All Implemented Interfaces:

MessageHandlerInterceptor<M>

public class CommandSequencingInterceptor<M extends CommandMessage>
extends Object
implements MessageHandlerInterceptor<M>

A MessageHandlerInterceptor implementation to sequence command execution.

Commands are sequenced based on a SequencingPolicy that specifies how to determine the sequence identifier from the CommandMessage that is being intercepted. Commands with the same sequence identifier will be executed sequentially, meaning that a command will wait for the previous command with the same identifier to complete before starting execution. Commands with different sequence identifiers can be executed concurrently.

Commands for which the policy returns Optional.empty() as sequence identifier will proceed without any sequencing constraints.

Since:

5.0.3

Author:

Jakob Hatzl

Constructor Summary

Constructors

Constructor	Description
CommandSequencingInterceptor(SequencingPolicy<? super CommandMessage> sequencingPolicy)	Construct a CommandSequencingInterceptor that sequences command execution based on the supplied SequencingPolicy.

Method Summary

Modifier and Type	Method	Description
MessageStream<?>	interceptOnHandle(M message, ProcessingContext context, MessageHandlerInterceptorChain<M> interceptorChain)	Intercepts a given message on handling before reaching the designated MessageHandler.

Methods inherited from class java.lang.Object

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

Constructor Details

CommandSequencingInterceptor

public CommandSequencingInterceptor(SequencingPolicy<? super CommandMessage> sequencingPolicy)

Construct a CommandSequencingInterceptor that sequences command execution based on the supplied SequencingPolicy.

Parameters:

sequencingPolicy - the SequencingPolicy to apply for retrieving the sequence identifier from the CommandMessage.

Method Details

interceptOnHandle

public MessageStream<?> interceptOnHandle(M message,
 ProcessingContext context,
 MessageHandlerInterceptorChain<M> interceptorChain)

Description copied from interface: MessageHandlerInterceptor

Intercepts a given message on handling before reaching the designated MessageHandler.

The interceptor is responsible for the continuation of the handling process by invoking the MessageHandlerInterceptorChain.proceed(Message, ProcessingContext) method on the given interceptorChain.

The given context contains contextual information. Any information gathered by interceptors may be attached to the context.

Interceptors are not allowed to change the type of the message handling result, as the dispatching component expects a result of a specific type.

Specified by:

interceptOnHandle in interface MessageHandlerInterceptor<M extends CommandMessage>

Parameters:

message - The message to intercept on handling.

context - The active processing context of the message being processed.

interceptorChain - The interceptor chain that allows this interceptor to proceed the dispatch process.

Returns:

The resulting message stream from MessageHandlerInterceptorChain.proceed(Message, ProcessingContext).