How to Access Session Scope in ADF BC

Often we need to access environment variables across all layers of ADF (Model and View-Controller). Usually we store environment variables in session scope, this makes them accessible for the duration of user session. Its common practice to retrieve values from session scope in View-Controller layer. However, is not so common to access session scope from ADF BC. Somehow there is such preconception, that its not possible to access session scope variables from ADF BC. But its possible (no need to add JSF libraries into Model) and I will explain in this short post how to do this.

If we want to store custom variable values in ADF BC, we can use UserData object - adf.userSession.userData. But this approach is not attractive - UserData is reset during passivation/activation and all custom variable values will be lost. Instead, we can store custom variable values in session scope. Download sample application - SecurityFormLogin_v2.zip.

Sample application populates environment variables during Login action (it sets server name and port):

Environment variables are stored in HTTP session, means accessible from session scope.

Now main topic of this post, you can access HTTP session from ADF BC by getting session scope from ADF context:

In this example, we are retrieving server name environment variable from HTTP session scope inside ADF BC prepareSession(Session) overridden method.

Let's test if value is not lost during passivation/activation. To test this, simply disable Application Module Pooling option from Application Module configuration:

Open sample application, login as redsam/welcome1:

Now, because AM pooling is disabled - on each request (button click) passivation/activation happens: