A resource adapter is a component that implements the Java EE Connector API architecture. It is similar to a datasource object, however, it provides connectivity from an Enterprise Information System (EIS) to a broader range of heterogenuous systems, such as databases, messaging systems, transaction processing, and Enterprise Resource Planning (ERP) systems.
The Java EE Connector Architecture (JCA) defines a standard architecture for Java EE systems to external heterogeneous Enterprise Information Systems (EIS). Examples of EISs include Enterprise Resource Planning (ERP) systems, mainframe transaction processing (TP), databases and messaging systems.
A resource adapter is a deployable Java EE component that provides communication between a Java EE application and an Enterprise Information System (EIS) using the Java Connector Architecture (JCA) specification. A resource adapter is often provided by EIS vendors to allow easy integration of their products with Java EE applications.
An Enterprise Information Systems can be any other software system within an organization. Examples include Enterprise Resource Planning (ERP) systems, database systems, e-mail servers and proprietary messaging systems.
A resource adapter is packaged in a Resource Adapter Archive (RAR) file which can be deployed to JBoss Enterprise Application Platform 6. A RAR file may also be included in an Enterprise Archive (EAR) deployment.