Oracle ADF: Which scope bean should be serializable and why??

Question

I am new to Oracle ADF. I have created a ADF web application using jDeveloper(11.1.2.4). When I am running my application in jdeveloper it is showing some warning messages. My application is working fine.

I am getting warnings like myBean is in pageflow scope but it is not serialized.

In adf we have following scopes

1. Application Scope
2. Session Scope
3. Request scope
4. View scope and more...

Could you please explain which scope bean should be serialized and why.

I read the blog ADF beans and serializableand in this blog I am unable to understand Frank comment. Please explain.

Thanks a lot in advanced.

Answer 1

My application is working fine.

I am getting warnings like myBean is in pageflow scope but it is not serialized.

Your application will work fine unless you deploy it to a cluster environment with failover.

Could you please explain which scope bean should be serialized and why.

If failover occurs, ADF is able to transfer the session to a different cluster member. Hence, the current state of your session (which is essentially represented by beans in the View, Page Flow and Session scope) needs to be transferred to a different application server which requires serialization and deserialization of those beans.

Failover will not occur between the start and the end of a request - hence, request scoped beans (Request, Backing Bean) need not be serializable. Most often, it is not even possible to serialize them since they contain references (bindings) to UIComponent objects which are themselves not serializable.

See also

• Cheat sheet: Oracle ADF bean memory scopes which shows the available bean scopes and which of them need to be serializable.
• Configuring High Availability for Oracle Application Development Framework