The Java EE 5 Tutorial

Messaging Contracts

To enable external systems to connect to a Java EE application server, the Connector architecture extends the capabilities of message-driven beans to handle messages from any message provider. That is, message-driven beans are no longer limited to handling JMS messages. Instead, EISs and message providers can plug any message provider, including their own custom or proprietary message providers, into a Java EE server.

To provide this feature, a message provider or an EIS resource adapter implements the messaging contract, which details APIs for message handling and message delivery. A conforming resource adapter is assured of the ability to send messages from any provider to a message-driven bean, and it also can be plugged into a Java EE server in a standard manner.