I'm working with JSF 2.0
I have a form in my admin section where I am going to select some users in a list.
The form (selectusers.xhtml) is adding these users to a list in a bean (SelectUsers.java).
After I have selected some user(s), I will pass the list of the user(s) from SelectUsers.java to another bean (AddAddressBean.java) and continue add information in another form (addadress.xhtml) which set other properties related to AddAddressBean for each user.
I do not know how to implement it. I would like that AddAddressBean.java shall be independent (so I can use it together with other beans), so I prefer that AddAddressBean.java shall not know about other beans.
Can you please help me? =)
B.R Carl
Several quick things come to mind :
Perhaps you could have a single bean only for those related pages, using #SessionScoped or the shorter CDI's #ConversationScope, or and this is the best of the three, the DeltaSpike #ViewAccessScoped
When clicking the button on page 1 where it'll take you to page 2, in the 1st bean, you can make use of Flash object to store objects you want to pass, and in the second bean's #PostConstruct method, you could get all the objects from the Flash object
If you dont mind using session scope, you can still have 2 beans, and one bean can refer to another bean using the jsf way(#ManagedProperty), or the Java EE inject way(#Inject) or the spring way if you use spring (#Autowired)
This how i implemented (used ConversationScoped as #bertie said ).
bean 1:
#Named("conversationBean1")
#ConversationScoped
public class ConversationBean1 implements Serializable {
//---start conversation----
}
bean 2:
#Named("conversationBean2")
#ConversationScoped
public class ConversationBean2 implements Serializable
{
#Inject
private ConversationBean1 conversationBean1;
}
Related
My configuration: JSF 2.1/Java 7
What I want is to have my own CDI scope, so I can declare a backing bean like this:
#SpecialScoped(name="specialName")
public class SpecialBackingBean {
}
All the parts regarding declaring the new scope type #SpecialScoped is ok, so I can annotate my classes with that scope and keep track when a certain page references such a backing bean.
However, What I need now is to detect that the user is moving to another web page and another backing bean so I can decide that the current #SpecialScoped BackingBean should or not be destroyed.
Any help will greatly appreciated!
TIA
I know there are loads of questions on SO regarding this exact issue, but I couldn't find a solution to my problem. I'm trying to use a #ManagedProperty in JSF 2. I used the example from this page, but mine's not working:
#ManagedProperty("#{userSession}")
private UserSession userSession;
public void setUserSession(UserSession userSession) {
this.userSession = userSession;
}
Both the parent bean and the bean injected are session scoped. Both beans have the #ManagedBean attribute. No faces-config.xml declarations, no EJBs, no use of Spring. One thing I noticed from that example is that both the bean classes implement Serializable. Mine do not, and I'm not sure if that is making the difference.
When I use this code, I get a NullPointerException when I try to operate on userSession. However, I know a session exists, because when I use #BalusC's findBean convenience method, it works. One thing with this though, is that my code only works if I call userSession = findBean("userSession") inside the same method where I'm "doing stuff". If I initialize userSession in the bean's constructor, I get another NPE. Any ideas?
This question already has an answer here:
#SessionScoped bean looses scope and gets recreated all the time, fields become null
(1 answer)
Closed 6 years ago.
ello
I have 2 Managed beans, one View scoped, the other Session scoped. The View scoped bean is defined as
#ManagedBean
#ViewScoped
public class InvoiceController implements Serializable {
private static final long serialVersionUID = 1L;
#ManagedProperty(value="#{invoiceService}")
private InvoiceService invoiceService;
The session scoped bean as
#ManagedBean
#SessionScoped
public class InvoiceService implements Serializable{
I am using the session scoped bean to hold a flag used to decide if a panel should be rendered, when I run this through the debug I find that every time I call the method on the sesison bean, it is a new instance of the bean and therefore does not retain the value of my flag between requests.
What am I doing wrong?
That can happen if you have imported #SessionScoped from the javax.enterprise.context package instead of from the javax.faces.bean package. The former works on CDI #Named beans only, while the latter works on JSF #ManagedBean beans only.
A JSF #ManagedBean without any valid scope would default to #NoneScoped which means that it's newly constructed on every single EL expression referencing the bean, such as the #ManagedProperty. This explains the symptoms you're seeing.
I had a similar problem. I use a save-method in the view scoped bean that calls a method in the session scoped bean to update some values.
This is what I found out by debugging (excuse my non-Java-guru English):
When first loading the page, the instance number of the injected session bean was for example 111111.
But in the save-method (and all other methods called by an action like a commandButton or action listeners btw), suddenly the session bean was of another instance (say 222222).
Both instances 111111 and 222222 contained the very same values.
All methods I called now were done in the 222222 instance and it changed values in there as I wanted it. But the 111111 instance remained untouched and unchanged.
So 222222 was basically a deep(?) clone of 111111, and not even a copy.
But, after the save-method was done and the page got reloaded, the original 111111 instance was used again in the view scope bean.
The 222222 instance just got thrown to the garbage.
My solution for this problem:
I'm not using the ManagedProperty injection anymore.
Instead I made some helper code to get the session bean wherever I need it (aka in the view scoped bean methods):
public Object getSessionBean(String sessionBeanName)
{
return FacesContext.getCurrentInstance().getApplication().getELResolver().getValue(FacesContext.getCurrentInstance().getELContext(), null, sessionBeanName);
}
For your example above, the call would be:
InvoiceService invoiceService = (InvoiceService) helper.getSessionBean("invoiceService");
Call it in your methods, do not store it as a field in the view scoped bean.
I hope this somehow helps you fix your problem.
If I am navigating from page one to page two, When I click on Page one's submit button, control goes to the managed bean written corresponding to page one, I want to fetch some result from database and show them to page two, If I set the Database values into the Managed bean corresponding to page two in the first Managed Bean's action method, then will I be able to get those on page two.
Please suggest if my approach is right?
You can inject let's say bean named Bean1 into Bean2 this way
#ManagedBean
#RequestScoped
public Bean2 {
#ManagedProperty(value="#{bean1}")//this is EL name of your bean
private Bean1 injectedBean;
public void setBean1(Bean1 value) {
injectedBean = value; //provide setter for it
}
#PostConstruct
private void init() {
List<YourData> list = injectedBean.getDBData(); //now you can fetch your list
}
Note that you have to provide setter for injection and scope of the injected bean should be always same or higher then the your beans scope (in this case Bean1 has to be at least RequestScope)
P.S. Also you could have some kind of DAO bean which could do all the database database operations for you (it can be EJB bean or even JSF Managed Bean) and then inject it to every ManagedBean which will require cooperation with your DB.
In this post Dynamic ui:include I asked how I could store an object in some state that could permit me to load a new windows, or tab, of the same browser and it was not stored also in the new windows. Adrian Mitev told me to use #WindowScoped, an option of MyFaces extension called CODI and i tried to implement it.
Now I should say that I'm blind and when I tried to open Apache Wiki my browser crashes on many pages so I can't read the guides.
However I add the source code on my project and the compiler didn't give any errors.
The problem is that now thepage when I try to retrive the bean that I stored by #WindowScoped doesn't work properly!
I use this code in my bean:
#ManagedBean (name="logicBean" )
#WindowScoped
In include.xhtml I retrieve the parameter with this code:
<ui:include src="#{logicBean.pageIncluded}"/>
And in my other beans I retrieve the LogicBean with this code (and I'm sure that the problem is on this code)
LogicBean l = (LogicBean) FacesContext.getCurrentInstance().getExternalContext().getSessionMap().get("logicBean");
How can I retrive the "correct" LogicBean object?
You're trying to get the LoginBean from the session map. This works only for session scoped beans with the standard JSF #SessionScoped annotation.
The canonical way to access other beans is using #ManagedProperty on the retrieving bean.
E.g.
#ManagedBean
#RequestScoped
public class OtherBean {
#ManagedProperty("#{logicBean}")
private LogicBean logicBean;
// Getter+Setter.
}
If you really need to access it inside the method block by evaluating the EL programmatically, you should be using Application#evaluateExpressionGet() instead:
FacesContext context = FacesContext.getCurrentInstance();
LogicBean logicBean = context.getApplication().evaluateExpressionGet(context, "#{logicBean}", LogicBean.class);
// ...