在JSF 2.0中刷新托管会话Bean

Question

After I commit some data into the database I want my session beans to automatically refresh themselves to reflect the recently committed data. How do I achieve this when using managed session beans in JSF 2.0?

Currently I have to restart the web server in order for the sessions to clear and load anew again.

Answer 1

2 ways:

1. Put them in the view scope instead. Storing view-specific data sessionwide is a waste. If you have a performance concern, you should concentrate on implementing connection pooling, DB-level pagination and/or caching in the persistence layer (JPA2 for example supports second level caching).

    @ManagedBean @ViewScoped public class FooBean { // ... } 

   ---

2. Add a public load() method so that it can be invoked from the action method (if necessary, from another bean).

    @ManagedBean @SessionScoped public class FooBean { private List<Foo> foos; @EJB private FooService fooService; @PostConstruct public void load() { foos = fooService.list(); } // ... } 

   which can be invoked in action method inside the same bean (if you submit the form to the very same managed bean of course):

     public void submit() { fooService.save(foos); load(); } 

   or from an action method in another bean (for the case that your managed bean design is a bit off from usual):

     @ManagedProperty("#{fooBean}") private FooBean fooBean; public void submit() { fooService.save(foos); fooBean.load(); } 

   This of course only affects the current session. If you'd like to affect other sessions as well, you should really consider putting them in the view scope instead, as suggested in the 1st way.

See also:

• How to choose the right bean scope?