Initializing application scope beans on startup

Hi All,
I need to initialize an application scope managed bean on startup, and not have to wait for it to be referenced the first time.
I was thinking of using ContextListener, but you dont have access to the faces context in the listener.
And you cant even extend FacesServlet, since its final.
Any ideas on how this can be achieved.
Thanks for your help!!

Try with FacesContext.getCurrentInstance() or http://www.jsffaq.com/Wiki.jsp?ptitle=How+to+access+FacesContext+from+the+Filter+or+Servlet%3F&page=HowToAccessFacesContextFromTheFilterOrServlet

Similar Messages

Looking for best practice on application scope beans

Hey â€“ a portal newbie here. Iâ€™ve got some application scope beans that need to be initialized on startup. First thought was to create a servlet that would set the bean. Then I saw the GlobalApp setting, but I think that looks like it is more session scope than applicationâ€¦ Looking to be corrected here if I am wrong.
Is there a place where these type of things traditionally happen? Read only, so no cluster worries (I think) Using WLP 8.1 SP4 and looking for best practices. Thanks for the help!

To support "code sharing" you need an integrated source code control system. Several options are out there but CVS (https://www.cvshome.org/) is a nice choice, and it's completely free and it runs on Windows, Linux, and most UNIX variants.
Your next decision is on IDE and application server. These are usually from a single "source". For instance, you can choose Oracle's JDeveloper and Deploy to Oracle Application Server; or go with free NetBeans IDE and Jakarta Tomcat; or IBM's WebSphere and their application server. Selection of IDE and AppServer will likely result in heated debates.

Application-scope bean finalizer ?

Hi,
Using JSF on GlassFish. Have an application-scope bean that creates a javax.persistence.EntityManager and holds it for the duration of the application.
When I redeploy, however, I get strange exceptions from TopLink which suggest that the state of the persistence provider is not correctly/fully cleared when undeploying. I suspect this because if I redeploy again, it (usually) works (unusually, I have to repeat the process 3 or 4 times).
So I'm thinking of adding calls to EntityManager.close or something, when the application bean is terminated. Is there such a thing as a bean finalizer, or some method that's called by the app server when the application is undeployed ?
BTW, the exception happens in this line of code:
List<Quantity> qList = em.createQuery("SELECT q FROM Quantity q").getResultList();
and the exception is:
java.lang.ClassCastException: cannot cast class com.xxxxxx.Quantity to com.xxxxxx.Quantity ! (needless to say that I have not changed the class inbetween)
Cheers,
K

Hi,
Using JSF on GlassFish. Have an application-scope bean that creates a javax.persistence.EntityManager and holds it for the duration of the application.
When I redeploy, however, I get strange exceptions from TopLink which suggest that the state of the persistence provider is not correctly/fully cleared when undeploying. I suspect this because if I redeploy again, it (usually) works (unusually, I have to repeat the process 3 or 4 times).
So I'm thinking of adding calls to EntityManager.close or something, when the application bean is terminated. Is there such a thing as a bean finalizer, or some method that's called by the app server when the application is undeployed ?
BTW, the exception happens in this line of code:
List<Quantity> qList = em.createQuery("SELECT q FROM Quantity q").getResultList();
and the exception is:
java.lang.ClassCastException: cannot cast class com.xxxxxx.Quantity to com.xxxxxx.Quantity ! (needless to say that I have not changed the class inbetween)
Cheers,
K

Application scope bean Vs. EJB

I want to cash some application data - and was thinking of using a singleton bean with application scope in my controller and JSP page.
<jsp:useBean id="myBean" scope="application" class="bean.datacash" />
I am not very familiar with EJBs - and wanted to know if it would be a mistake not to use an EJB to perform that task.
Is there a downside to my approach?
Thanks for any insight
Mike

Entity EJB'S are used as a kind of data persistence, mostly to Databases. In a way it's like a kind of cache but any changes you make to an EJB are usually persisted to the underlying data storage on a regular basis.
Session EJB's are more for business logic and depending on the type of Session Bean you use can either remain persisted in a session state or used and thrown away.
EJB's also require alot of code so depending on your application requirements it is kind of a big decision.
Is the data your wanting to cache to be shared by all users using the application? Are there any race conditions that may be met by concurrent access to the data? What do you plan to do with the cached data store it in a database or just make it available to share?
If you want to look into using EJB's then your going to require an EJB Container to run them in (this can be standalone like OpenEJB or as part of an J2EE Application server like JBoss or Oracle Application Server to name just a couple).
Using the Singleton Javabean can keeps things simple but once you start to synchronize methods with multiple users you can find some slowing down of the logic as the singleton tries to complete a request before getting onto the next.
The [url http://jakarta.apache.org]Jakarta team offer a package called commons pooling which is designed as a pooling framework (also a way of caching) that can come in handy, I've used it to create a custom JDBC Connection pooler and it works quite well when you get the hang of it.
Another thing to consider is the load the application may be under at it's busiest time. How many concurrent users do you expect to access the application?
Sorry I can't give you a real answer as that is entirely up to you and your requirements. If you have a small app that has around 20-50 users then EJBs are bit of an overkill. If you find you'll have 100+ users with lots of data to manage then EJB's are probably a good option.
If you have a look at [url http://www.theserverside.com]the serverside web site you may find a couple of articles on data persistence or check out some of the online magazines which also have articles on this same topic.
Anthony

How can a session scope bean access an application scope bean - help

Hello,
I have a JSP page that has references to an Application Scope and a Session Scope bean...
<jsp:useBean id="myWebApp" scope="application" class="com.my.web.WebApplication" />
<jsp:useBean id="myWebSession" scope="session" class="com.my.web.WebSession" />
I would like the WebSession access methods in the WebApplication ... Can/ How does the WebSession object lookup the reference to WebApplication object?

I don't think you should make the WebSession implement the session listener.
The session listener will be created once, at the start of the servlet context and would be listening to all sessions. So you would have one instance of the WebSession belonging to the context (though not as an attribute), and others belonging to each session. This will be confusing in your code, I think.
I would suggest having a different class act as the HttpSessionListener. Perhaps do something like this:
public class WebSessionInjector implements HttpSessionListener {
public void sessionCreated(HttpSessionEvent e) {
    WebApplication webApp = (WebApplication)(e.getSession().getServletContext().getAttribute("webapp"));
    WebSession mySession = new WebSession();
    mySession.setWebApplication(webApp);
    e.getSession().setAttribute("mySession", mySession);
public void sessionDestroyed(HttpSessionEvent e) { ... }
}You may be able to use the WebApplication object itself as the listener ...
Or, you could make the WebSession implement the HttpSessionBindingListener and use the valueBound event much like the sessionCreated event above, but from inside the WebSession object:
public class WebSession implements HttpSessionBindingListener {
public void valueBound(HttpSessionBindingEvent e) {
    WebApplication webApp = (WebApplication)(e.getSession().getServletContext().getAttribute("webapp"));
    this.setWebApplication(webApp);
public void valueUnbound(HttpSessionBindingEvent e) { ... }
}

How-to remove application scope bean

I've found the following snippets to get rid of a session bean (to have it removed / recreated):
snippet 1:
FacesContext
     .getCurrentInstance()
     .getApplication()
     .createValueBinding( "#{yourBeanName}").setValue(FacesContext.getCurrentInstance(), null );snippet 2:
FacesContext.getCurrentInstance().getExternalContext().getSessionMap().remove("userBean");Would that work for application scoped beans as well? Is there a way of getting a list of all jsf beans? I need to re-initialize the web-application without deployment :S
thanks,
david

Yeah, I've tried it and it's looking good.
Is there any way I can get a list of (application scoped) jsf beans?

How to init an application scope backing bean once app server startup?

Hi guys,
I got an application scope backing bean but I don't know how to initialize it once the app server startup ! I need all the webpage to be able to get the 'defaultCountry' value once the app server startup !
<managed-bean>
<managed-bean-name>applicationScopeBean</managed-bean-name>
<managed-bean-class>com.borneo.webapp.action.ApplicationScopeBean</managed-bean-class>
<managed-bean-scope>application</managed-bean-scope>
<managed-property>
<property-name>defaultCountry</property-name>
<property-class>java.lang.String</property-class>
<value>Singapore</value>
</managed-property>
</managed-bean>
Pls help, Thanks !
regards,
Mark

write a context listener and set up your web.xml as such
<listener>
<listener-class>com.package.ContextListener</listener-class>
</listener>
Then your class should inmplement ServletContextListener interface.
The 2 methods need to be implemented
public void contextDestroyed(ServletContextEvent sc_event) { }
public void contextInitialized(ServletContextEvent sc_event) { }
Hope that helps

Killing a bean with application scope?

Is there any way to kill a bean with application scope?
I am writing a web application, that most likely the browser window will never be closed. The problem is a user is authenticated onto our site but because the bean containing the users acct info is application scope, if another user logs in it still shows the old user as logged in. So on logout i would like to kill the application, the bean, servletContext...anything that will refresh the bean and the corresponding jsp. Any help is much appreciated.

There is an indirect way if you know servlets. The "application" implicit object that you use in your JSP is the javax.servlet.ServletContext object. Instead of declaring your bean using the jsp:useBean tag, directly put your objects into the ServletContext using ServletContext.putAttribute() method. Objects put in the ServletCOntext are available to all pages in the application. Just use the ServletContext.getAttribute() method to retrieve this bean in any other page.
To "kill the bean", just reset the value of this object to null by calling putAttribute(null).

Updating Beans in Application Scope

The problem is that i dont know how to update a bean in an application scope:
in EA4 i use this instruction to update a bean property:
// get the faces context
FacesContext facesContext = FacesContext.getCurrentInstance();
// update a property in application scope
(Util.getValueBinding("BeanName.propertyName")).
setValue(facesContext,"text");
and it worked ok in jsp:
<h:output_text valueRef="BeanName.propertyName" />
Now in version 1.0 i wrote:
Application app = facesContext.getApplication();
errorAplicacion = (ErrorAplicacion)app.createValueBinding("#{beanName}").
getValue(facesContext);
How should i update this value in application scope to be used in the jsp ?
I use in jsp:
<h:output_text value="#{BeanName.beanProperty}"/>
But i receive in logs:
Expression BeanName.beanProperty does not follow the syntax #{...}
And the result is null
Thanks a lot
German

If you are quoting your 1.0 code literally, you've got a case mismatch between "#{beanName}" when you create the value binding expression and "#{BeanName}" in the JSP page. As with most things in Java, the names are case sensitive.
Craig McClanahan

Setting Beans in Application Scope

How do I set beans in application scope at the start of a JSF web app? I'd like to be able to do something similar to the Struts plugin.

Hi,
I also tried to use a servletcontextlistener. The problem is, that I cannot
put any beans in the facescontext, because a NullpointerExcpetion
is thrown. In the contextInitialized-Method I do the following:
FacesContext context = FacesContext.getCurrentInstance();
ApplicationFactory factory =
(ApplicationFactory) FactoryFinder.getFactory(
FactoryFinder.APPLICATION_FACTORY);
Application application = factory.getApplication();
ValueBinding binding = application.createValueBinding( "#{Bean}" );
In the createValueBinding-method a Exception is thrown. So I cannot call
createValueBinding when I am not in a facescontext.
Can anyone help me?
Thanks
Andy

Application scope java beans not behaving....

I am using WL 5.1, sp8, on NT....
          I am running jsp code that declares java beans of application scope....
          However, it doesn't appear to be resolving the application scope
          properly, it seems to instantiate a new Bean each time I go to
          a new page within the same application....
          One thing I am not clear on, is whether I have properly configured
          the WebApp....I have just been assuming that all pages within
          the same path sub-directory are of the same application, but that
          doesn't appear to be working....
          I haven't found any weblogic.properties settings for defining WebApps,
          that will share application scope, etc....
          I assume there is a simple answer here, I appreciate any help...
          Thanks,
          Jason Rosenberg


Jason,
          WLS 5.1.0 is up to service pack level 12 now, which you should go to
          http://support.bea.com/welcome.jsp and login to download from the "Supports
          Download" section. Note that you need to be a paying customer to see this
          section. After applying sp12 you should take a look at our web app docs
          here http://bernal.beasys.com/release/docs51/classdocs/webappguide.html for
          instructions on setting up a web app and registering it in wls 5.1.
          "Jason Rosenberg" <[email protected]> wrote in message
          news:[email protected]...
          > I am using WL 5.1, sp8, on NT....
          >
          > I am running jsp code that declares java beans of application scope....
          >
          > However, it doesn't appear to be resolving the application scope
          > properly, it seems to instantiate a new Bean each time I go to
          > a new page within the same application....
          >
          > One thing I am not clear on, is whether I have properly configured
          > the WebApp....I have just been assuming that all pages within
          > the same path sub-directory are of the same application, but that
          > doesn't appear to be working....
          >
          > I haven't found any weblogic.properties settings for defining WebApps,
          > that will share application scope, etc....
          >
          > I assume there is a simple answer here, I appreciate any help...
          >
          > Thanks,
          >
          > Jason Rosenberg
          >
          >
          >
          >
          >
          >
          >

Is Weblogic Cluster supports Application scope Objects?

          Our Application is mainly depends on Application scope objects. On one m/c, it
          is perfect.
          Now, we want to support the failover , load balancing ... (High Availability).
          I know, weblogic cluster supports HttpSessions, EjbObjects ... etc. What about
          Application scope objects.
          we are planning for weblogic server which supports the our requirements.
          If not, what is the solution to make it work by using Weblogic server.
          for eg: I can give what type of application we are developing --- similar to
          textchat.
          our application is real time application.


Even a singleton is not good enough as singletons are good only in the VM they were
          created it. One way is to have a distributed object such as a stateful session bean of
          which only one instance exists. U can create it at startup and store its handle in
          some persistent storage as well as a singleton. This ensures that even if the
          singleton doesnt contain it the refgerence to it can be obtained.
          There will be some problems with this setup as people should not allow it to create
          instances of it . Any such endeavor will lead to a CacheFullException.
          But essentially that seems possible.
          Even the 2.3 Servlet specification mandates that ServletContext and Application level
          object is only valid inside the JVM which created it. HttpSessions are replicated
          SessionContexts are not and are not likely to be in any J2EE application server
          Sameer
          Devi wrote:
          > One more comment from my side,
          > U mentioned "EXCEPT FOR JNDI" , if this is possible, how can we acheive?
          > Can U give brief description ? Take textchat example itself? since, our application
          > is almost have same mechanism. If it is < 1 sec delay means acceptable for this
          > release.
          >
          > Thanks,
          > Devi
          >
          > "Cameron Purdy" <[email protected]> wrote:
          > >Weblogic doesn't support replicated / synchronized app scope objects
          > >across
          > >a cluster except for JNDI, which is probably not a good solution for
          > >what
          > >you are describing.
          > >
          > >If you need a real-time shared fault-tolerant fail-overable high-performance
          > >load-balanced high-scale data store, then let me know when you find one
          > >;-)
          > >.... seriously, there are not a whole lot of good general purpose solutions
          > >in this space. There are some things to look at but they are all expensive:
          > >
          > >Persistent PowerTier on top of Oracle - a caching entity EJB server
          > >Jasmine (or whatever it is called this week) - an object oriented
          > >distributed data store
          > >....
          > >
          > >Peace,
          > >
          > >--
          > >Cameron Purdy
          > >Tangosol Inc.
          > ><< Tangosol Server: How Weblogic applications are customized >>
          > ><< Download now from http://www.tangosol.com/download.jsp >>
          > >
          > >
          > >"Devi" <[email protected]> wrote in message
          > >news:[email protected]...
          > >>
          > >> Our Application is mainly depends on Application scope objects. On
          > >one
          > >m/c, it
          > >> is perfect.
          > >> Now, we want to support the failover , load balancing ... (High
          > >Availability).
          > >>
          > >> I know, weblogic cluster supports HttpSessions, EjbObjects ... etc.
          > > What
          > >about
          > >> Application scope objects.
          > >> we are planning for weblogic server which supports the our requirements.
          > >>
          > >> If not, what is the solution to make it work by using Weblogic server.
          > >> for eg: I can give what type of application we are developing ---
          > >similar to
          > >> textchat.
          > >> our application is real time application.
          > >>
          > >
          > >

Avoiding request scope bean clashes for task flow calls

Hi,
I have two task flows, Tf1 calls Tf2 using a task flow call activity. The structures of the task flows are as follows:
Tf1
Managed Bean: TfBean, request scope
    class Tf1Bean
      has property goTf2Button
View: View1
    Button bound to #{TfBean.goTf2Button}
      Action -> task flow call to Tf2
Tf2
Managed Bean: TfBean, request scope
    class Tf2Bean
      has property testButton
View: View2
    Button bound to #{TfBean.testButton}
As you can see both have a request scope bean called TfBean but these are different classes in each. The bean classes have different properties for binding the components on the two pages.
When I click the button in View1 to navigate I get an error telling me that class Tf1Bean does not have the property testButton. Clearly Tf2Bean is not being instantiated as TfBean already exists for the request.
I'm guessing this is expected behaviour and it seems logical.
My question however is what would be good standards or practices to avoid this?
One way would be a naming convention, however what if I am consuming Tf2 from a library? In this case it would ideally work as a black box and I should not be concerned about it's implementation, specifically names chosen for internal managed beans. Even if it was not a problem initially, the developer of the task flow could add or change the name of a request scope bean introducing a conflict at a later stage.
Thanks,
Kevin

Hi Frank,
Good to meet you at UKOUG Tech13 yesterday. I changed my test case from request scope to backing bean scope. Unfortunately I still get the same error:
<RichExceptionHandler> <_logUnhandledException> ADF_FACES-60098:Faces lifecycle receives unhandled exceptions in phase RENDER_RESPONSE 6
javax.faces.FacesException: javax.el.PropertyNotFoundException: The class 'yyy.view.Tf1Bean' does not have the property 'testButton'.
at com.sun.faces.application.ApplicationImpl.createComponentApplyAnnotations(ApplicationImpl.java:1900)
at com.sun.faces.application.ApplicationImpl.createComponent(ApplicationImpl.java:446)
at javax.faces.webapp.UIComponentELTag.createComponent(UIComponentELTag.java:222)
at javax.faces.webapp.UIComponentClassicTagBase.createChild(UIComponentClassicTagBase.java:506)
at javax.faces.webapp.UIComponentClassicTagBase.findComponent(UIComponentClassicTagBase.java:744)
at javax.faces.webapp.UIComponentClassicTagBase.doStartTag(UIComponentClassicTagBase.java:1311)
at org.apache.myfaces.trinidad.webapp.UIXComponentELTag.doStartTag(UIXComponentELTag.java:67)
at oracle.adfinternal.view.faces.unified.taglib.nav.UnifiedCommandButtonTag.doStartTag(UnifiedCommandButtonTag.java:51)
...etc.
What I think is happening, please correct me if I'm wrong...
Running Tf1, page View1 is displayed.
Clicking the button on View1 initiates a request and an instance of Tf1Bean is instantiated for the managed bean named TfBean.
During the request navigation occurs to Tf2 and hence page View2.
View2 needs a property in TfBean called testButton.
There is already a managed bean instantiated for this request called TfBean, however this is of class Tf1Bean and does not have the property.
I have a simple workspace showing this if you want me to send it to you. I am using 11.1.2.4 by the way.
Thanks,
Kevin

What are the pros and cons of storing heavely used CFCs in the application scope?

I've been storing all the required CFCs for a site in the application scope. During onApplicationStart I do something like this application.objSomeCfc =CreateObject('component', 'com.someCfc').init().
Here is my reasoning.
Get the CFCs initialized once and stored in memory for better performance.
Using CreateObject several times on each page load can have a negative impact on performance.
Having one place to create application scoped CFCs makes it easier to manage code.
So is my thinking flawed? Are there any additional pros or cons for dealing with CFCs? Is there any docs, articles, blogs, videos, frameworks, ...... that I should check that may change my perspective on how I'm doing this?
Thanks

Your approach is fine, depending on how many and what type of CFCs you are talking about. If they are "singletons" - that is, only one instance of each CFC is needed to be in memory and can be reused/shared from multiple parts of your application - caching them in the application scope is common. Just make sure they are thread safe ("var" or local.* all your method variables).
You might consider taking advantage of a dependency injection framework, such as DI/1 (part of the FW/1 MVC framework), ColdSpring, or WireBox (a module of the ColdBox platform that can be used independently). They have mechanisms for handling and caching singletons. Then you wouldn't have to go to the application scope to get your CFC instances.
-Carl V.

Oracle-ADF inlineFrame initializing view scoped bean twice

I am facing strange issue related with af:inlineFrame component. Trying to display/render ADF page inside of af:popup within af:inlineFrame component. The weird thing is when the popup displayed; view scoped bean's @PostConstruct method called twice. That means bean is initialized twice. However it needed to be initialized once since bean is referenced from the page that is going to be displayed inside af:inlineFrame.
Correct flow gotta be:
Click to button openPopup() method called.
openPopup() sets URI then opens popup.
inlineFrame source property set as it's going to display framePage.jspx.
JSF scans framePage.jspx code finds out there is a reference to FrameBean inside af:outputLabel
Construct FrameBean then call @PostConstruct method.
Call appropriate getter and render page.
What happens in my case:
Click to button openPopup() method called.
openPopup() sets URI opens popup.
inlineFrame source property set as it's going to display framePage.jspx.
JSF scans framePage.jspx code finds out there is a reference to FrameBean inside af:outputLabel
Construct FrameBean then call @PostConstruct method.
Call appropriate getter and render page.
Construct FrameBean then call @PostConstruct method.
Call appropriate getter and render page.
Popup located like:
<af:popup id="mainPopup" binding="#{mainBean.mainPopup}">
<af:dialog id="mainDialog">
<af:inlineFrame source="#{mainBean.URI}"> </af:inlineFrame>
</af:dialog>
</af:popup>
Showing popup via af:button action="#{mainBean.openPopup}":
public void openPopup() {
this.setURI("http://localhost:7001/app/framePage.jspx");
RichPopup.PopupHints hints = new RichPopup.PopupHints();
this.getMainPopup().show(hints);
framePage.jspx:
<?xml version='1.0' encoding='UTF-8'?> <jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" version="2.1" xmlns:f="http://java.sun.com/jsf/core" xmlns:af="http://xmlns.oracle.com/adf/faces/rich"> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <jsp:directive.page contentType="text/html;charset=UTF-8" />
<f:view>
<af:document title="Frame Demo" id="demoDocument">
<af:form id="demoForm">
<af:outputLabel value="#{frameBean.commonId}"> </af:outputLabel>
</af:form>
</af:document>
</f:view>
</jsp:root>
FrameBean:
@ManagedBean
@ViewScoped
public class FrameBean {
private String commonId;
@PostConstruct
public void afterInit() { }
public String getCommonId() {
return commonId;
public void setCommonId(String commonId) {
this.commonId = commonId;
Making FrameBean @SessionScoped solves this issue since bean is kept with session but I don't want to keep it within session. Also setting source property of af:inlineFrame in jspx as hardcoded not fixing the problem.

im using ADF Essential on Glassfish 3.1 with no problem, but glassfish is heavyweight. I think Oracle ADF is not dependent to Application Server , then i tried to use my project with Tomcat 7. I deployed my application on Tomcat 7 , but im getting some exceptions.
Not all application servers support Oracle ADF.
Refer the certification matrix, Tomcat 7 is not listed as being supported.
http://www.oracle.com/technetwork/developer-tools/jdev/index-091111.html

Initializing application scope beans on startup

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