What is Spring Integration, and what problem does it solve?

Spring Integration

Spring Integration is a framework implementing the well-known Enterprise Integration Patterns (EIP) — a catalog of proven solutions for connecting disparate systems (message routing, transformation, filtering, aggregation) — as Spring beans, letting you wire together complex integration flows (reading from a file directory, transforming records, routing them conditionally, calling an external system) declaratively rather than hand-writing bespoke glue code for every point-to-point integration.