Shared components across containers

This section describes the new components and changes components that can be shared across the Web container and the EJB container. That is, these components can be used both by the application presentation layer and the application logic layer.

Common Hierarchical Area
This component, called the CHA, uses J2EE technology to wrap contexts as EJBs so that they are accessible by any entity running in the EJB container. This enables a business process to get the data it needs. Because the CHA contexts are EJBs, non-toolkit applications can use the CHA to contain general global session information.
CHA contexts
The contexts running in the application server side, which is called CHA contexts, is different from those running in the Java(TM) client side. Compared with the contexts running in the Java client side, the CHA contexts have additional wrapping so that they exist as EJBs. There is no connection between the contexts and CHA contexts
Events
The events running in the application server side have a different structure than those running in the Java client side. The application server side events use Java Message Service (JMS) for events propagation.
CHA Formatter Service
This service formats data objects into strings and parses strings into data objects so that data can move into and out of CHA contexts.
Externalizers
Externalizers exist in both layers except that the application logic layer does not contain externalizers for toolkit entities that are purely related to presentation such as flow processors and views.