Editing Enterprise application integration (section)

=== Technologies ===
Multiple technologies are used in implementing each of the components of the EAI system:{{citation needed|date=February 2020}}
;Bus/hub: This is usually implemented by enhancing standard middleware products ([[application server]], message bus) or implemented as a stand-alone program (i.&nbsp;e., does not use any middleware), acting as its own middleware.
;Application connectivity: The bus/hub connects to applications through a set of '''adapters''' (also referred to as '''connectors'''). These are programs that know how to interact with an underlying business application. The adapter performs one-way communication(unidirectional), performing requests from the hub against the application, and notifying the hub when an event of interest occurs in the application (a new record inserted, a transaction completed, etc.). Adapters can be specific to an application (e.&nbsp;g., built against the application vendor's client libraries) or specific to a class of applications (e.&nbsp;g., can interact with any application through a standard communication protocol, such as [[SOAP]], [[SMTP]] or [[Action Message Format]] (AMF)). The adapter could reside in the same process space as the bus/hub or execute in a remote location and interact with the hub/bus through industry-standard protocols such as message queues, web services, or even use a proprietary protocol. In the Java world, standards such as [[J2EE Connector Architecture|JCA]] allow adapters to be created in a vendor-neutral manner.
;[[File format|Data format]] and [[data transformation|transformation]]: To avoid every adapter having to convert data to/from every other application's formats, EAI systems usually stipulate an application-independent (or common) data format. The EAI system usually provides a data transformation service as well to help convert between application-specific and common formats. This is done in two steps: the adapter converts information from the application's format to the bus's common format. Then, semantic transformations are applied to this (converting zip codes to city names, splitting/merging objects from one application into objects in the other applications, and so on).
;Integration modules: An EAI system could be participating in multiple concurrent integration operations at any given time, each type of integration being processed by a different integration module. Integration modules subscribe to events of specific types and process notifications that they receive when these events occur. These modules could be implemented in different ways: on [[Java (programming language)|Java]]-based EAI systems, these could be [[web application]]s or [[Enterprise JavaBean|EJBs]] or even [[POJO]]s that conform to the EAI system's specifications.
;Support for [[Database transaction|transaction]]s: When used for process integration, the EAI system also provides transactional consistency across applications by executing all integration operations across all applications in a single overarching distributed transaction (using [[two-phase commit protocol]]s or [[compensating transaction]]s).