receive inbound event messages. An agent listener monitors a Business Event System

agent for incoming messages and dequeues messages using the agent's queue handler.

You should run agent listeners for your local inbound agents. Run PL/SQL agent

listeners to process event subscriptions with a PL/SQL rule function in the database,

and run Java agent listeners to process event subscriptions with a Java rule function in

the middle tier.

When an event message is dequeued, the Event Manager begins subscription

processing for the event. The Event Manager searches for and executes any active

subscriptions by the local system to that event with a source type of External, and also

any active subscriptions by the local system to the Any event with a source type of

External. The agent listener exits after all event messages on the agent's queue have

been dequeued.

The PL/SQL agent listener program is defined as a service component type in the

Generic Service Component Framework. This framework helps to simplify and

automate the management of background Java services.

Oracle Workflow provides several seeded agent listener service components to process

messages on standard agents.

• Workflow Deferred Agent Listener - Handles messages on WF_DEFERRED to

support deferred subscription processing. This service component is started

automatically by its container.

• Workflow Deferred Notification Agent Listener - Handles notification messages on

WF_DEFERRED to support outbound notification processing. This service

component is started automatically by its container.

• Workflow Error Agent Listener - Handles messages on WF_ERROR to support

error handling for the Business Event System. This service component is started

automatically by its container.

• Workflow Inbound Notifications Agent Listener - Handles messages on

WF_NOTIFICATION_IN to support inbound e-mail notification processing. This

service component is started automatically by its container.

• ECX Inbound Agent Listener - Handles message on ECX_INBOUND to support

Oracle XML Gateway processing. This service component must be started

7-60 Oracle Workflow Administrator's Guide

manually. For more information, see the Oracle XML Gateway User's Guide.

• ECX Transaction Agent Listener - Handles message on ECX_TRANSACTION to

support Oracle XML Gateway processing. This service component must be started

manually. For more information, see the Oracle XML Gateway User's Guide.