i define a queue channel
@Bean("mail-action-laundry-list-channel")
public MessageChannel mailRecipientActionMessageChannel() {
return new QueueChannel(20);
}
the flow below, i will aggrate messages from the queue channel, i tried this:
@Bean
public IntegrationFlow mailRecipientActionLaundryListMessageFlow(@Qualifier("laundryListMessageHandler") MessageHandler laundryListMessageHandler) {
return IntegrationFlows.from("mail-action-laundry-list-channel")
.log("--> laundry list messages:：")
.aggregate(aggregatorSpec -> aggregatorSpec
.correlationExpression("#this.payload.email")
.releaseExpression("#this.size() == 5")
.messageStore(new SimpleMessageStore(100))
.groupTimeout(2000))
.transform(laundryListMessageToItemProcessDtoTransformer())
.handle(laundryListMessageHandler)
.get();
}
but why it aggrate first 5 messages from the channel always, and aggrate other message no longer
You need to configure expireGroupsUponCompletion(true) on the aggregator:
When set to true (default false), completed groups are removed from the message store, allowing subsequent messages with the same correlation to form a new group. The default behavior is to send messages with the same correlation as a completed group to the discard-channel.
Looks like your subsequent messages from the queue has the same email property. Therefore an aggregator can't form a new group for the same correlation key.