This figure shows the communication flow for inbound communication. After an initiating communication from the resource adapter to the work units in the application server, communications are shown in the following sequence:
From the EIS to a queue in the message provider
From the message provider to the work units
From the work units to the MDB (message endpoint)
From the MDB to the J2EE component
From the J2EE component back to the MDB
From the MDB back to the work units
From the work units to the EIS
The EIS and message provider are depicted as outside OC4J; everything else is inside OC4J.
The figure also shows the roles of the relevant system contracts, as follows:
Work units operate through the work management and transaction inflow contracts.
Communication between the work units and MDB is through the message inflow contract.
The lifecycle of the resource adapter (starts and stops) is governed by the lifecycle contract.