Intent

Sometimes in enterprise systems there is a need to group incoming data in order to process it as a whole. For example you may need to gather offers and after defined number of offers has been received you would like to choose the one with the best parameters.

Aggregator allows you to merge messages based on defined criteria and parameters. It gathers original messages, applies aggregation strategy and upon fulfilling given criteria, releasing merged messages.

Diagram

Applicability

Use the Aggregator pattern when

You need to combine multiple incoming messages
You want to process grouped data

Credits