Spring集成中分组和忽略消息

Question

I have a spring integration application that deals with different trade types in the database which I transform, filter and route to it's appropriate corresponding tradeEventChannel

New RowId->[GateAway]---->|======|----->Transformer->|======|------>Filter->|======|--->Router|======|--->repoTradeChannel

For one specific trade event type (repoTradeChannel), there are two possible cases:

1. user trades an open repo trade, this translates into one repo (open message) TradeEvent that should be routed to repoTradeChannel for processing. When the trade is termed (hours, days or weeks later), a second messages (the term message) is received and that should also be processed .
2. user trades an term repo trade, this translates into two repo in the database (open and term message) TradeEvent . However, only one should be routed to repoTradeChannel for processing as the second one causes issues. The second one is received into the channel almost lets say within 3 minutes.

In both of the above cases, the TradeEvent / message can be grouped by id and other properties on the TradeEvent class.

My question is, can I use an aggregator to group the messages that come in the second case and disregard the second one? I can look at for example the id or action fields to determine which is not acceptable. In the second case, the message/event is received within a few minutes, whereas in the first case the second message (term message) can be delayed, hours, days, or weeks.

Is there strategy I can use to handle these cases at aggregation as I cannot stop the incoming messages and filter. I need to rely on grouping, then determining that the second message is not useful in the second case.

what would the implementation look like? Should I be using a different strategy like caching instead?

In summary, the issue is really how do I differentiate the term message that is received in case 1 vs case 2, where case 2 one should be suppressed.

Answer 1

You question is too business-specific and it's hard to answer directly without any plain common explanation or code on the matter.

Anyway you really can use an aggregator with the correlationStrategy based on that id or action fields. The releaseStrategy should be as simple as MessageCountReleaseStrategy with the threshold = 2 .

What to output from the aggregator you can decide in the MessageGroupProcessor implementation: you can merge both messages to a single one. You can still produce a list of them, or just ignore one of the message and produce only the another one.