The Business Process Component provides two interfaces for toolkit entities. The WSIF interface enables Struts actions to launch a process using a WSIF message through a WSIF Access action. The EJB interface enables Struts actions to launch a process using a EJB method through an EJB Access action, or other toolkit entities to launch a process through an EJB method call using an invoker directly.
To support toolkit processes within WebSphere(R) Business Integration Server Foundation, the Business Process Component provides the Abstract Layer. The Abstract Layer provides mapping between messages (both requests and responses) and process contexts, enables the business processes to access other toolkit components such as CHA, and manages the initialization and termination of the business processes. Setting up the process involves creating the process context using data mapped from the request (using a request mapper) and chaining the process context to the session context.
If work areas are not being used between the application presentation and application logic layers, the application presentation layer identifies the session within the WSIF request message if the process started through the WSIF interface or the invocation parameter if the process started through the EJB interface. If work areas are being used between the two layers, the application presentation layer passes the session data (session ID and, if applicable, sub-session ID) using this feature.
When the request enters the process engine, the Abstract Layer retrieves the session data and uses it to retrieve the session context from the CHA. The Abstract Layer stores the session data in a work area. This makes the session data available to each activity in the business process.
The following diagram shows the Business Process Component parts and other toolkit entities that a process might interact with during its flow. For a description of how and when these interactions occur, see How the Business Process Component works.