Hi
Are there any best practices for using Managed
Beans?
We plan to use our own custom-built JSF components.
Need to understand how to design backing beans for performance/effort
optimization.
For example :
For example :
1. How to make managed beans thread-safe for
concurrent requests, without compromising on efficiency/speed?
2. How to enforce the J2EE security with
managed-beans?
3. How to decide the scope of these beans to ensure
minimal data-storage in session?
4. How to decide the granularity at which a
managed-bean should be used for example :
4.1 One bean-per-component
Advantages :
a) if complex components require special data-holding/processing/event-handling capabilities from bean
(e.g. datagrid model,tree model,menu model)
Problems :
- with multiple components in a page/form
a) it becomes tedious to debug/change/track which bean serves which component
b) if session scope is required, too many beans will be cached in session
c) unnecessarily too many beans will be created on server (= n pages * m components-per-page)
d) unnecessarily increases the length of faces-config.xml
Advantages :
a) if complex components require special data-holding/processing/event-handling capabilities from bean
(e.g. datagrid model,tree model,menu model)
Problems :
- with multiple components in a page/form
a) it becomes tedious to debug/change/track which bean serves which component
b) if session scope is required, too many beans will be cached in session
c) unnecessarily too many beans will be created on server (= n pages * m components-per-page)
d) unnecessarily increases the length of faces-config.xml
4.2 One bean-per-form
Advantages :
a) in multi-form web pages, to ensure the functional behaviour of each form is separate/modular in its own bean.
b) each managed-bean would map to specific/meaningful functionality/user-interaction in use-case.
Advantages :
a) in multi-form web pages, to ensure the functional behaviour of each form is separate/modular in its own bean.
b) each managed-bean would map to specific/meaningful functionality/user-interaction in use-case.
Problems :
- if form includes complex components (datagrid/tree/menu) requiring a specialised bean class, then
a) either one of the specialized bean has to be augmented with additional logic to handle data/events for all other components within the form
(Not good, as it mixes-up the responsibilities of component-specific-beans, and the bean may no more be reusable in another form)
- if form includes complex components (datagrid/tree/menu) requiring a specialised bean class, then
a) either one of the specialized bean has to be augmented with additional logic to handle data/events for all other components within the form
(Not good, as it mixes-up the responsibilities of component-specific-beans, and the bean may no more be reusable in another form)
b) or without using component-specific
beans, only single form bean should handle the data/events for all components in
the form?
(Neither good, since if a complex tree-compoent is reused in multiple forms, then the logic to handle data/events for such a component will be repeated in those many form-specific managed beans)
(Neither good, since if a complex tree-compoent is reused in multiple forms, then the logic to handle data/events for such a component will be repeated in those many form-specific managed beans)
4.3 One bean-per-page
Advantages :
a) seems more modular/meaningful way - since a page would map to some feature within the use-case
b) bean will contain only behaviour which is relevent for the associated page/function within use-case
Problems :
a) in multi-form pages, can single bean handle data/events for multiple forms?
b) if page uses complex component (e.g datagrid, tree) that needs its own bean - how does page-bean exchange data with component-bean?
Advantages :
a) seems more modular/meaningful way - since a page would map to some feature within the use-case
b) bean will contain only behaviour which is relevent for the associated page/function within use-case
Problems :
a) in multi-form pages, can single bean handle data/events for multiple forms?
b) if page uses complex component (e.g datagrid, tree) that needs its own bean - how does page-bean exchange data with component-bean?
Thanks,
Arti
Arti
