I have a JSF managed bean and a JAX-RS web service.
ManagedBean - myBean class
#ManagedBean
#ViewScoped
public class MyBean implements Serializable {
private String id;//getters && setters ommited
}
Web Service - myService class
#ApplicationPath("/myService")
#Path("/")
#Consumes("application/json")
public class MyService extends Application {
#Inject
MyBean myBean;
#Path("doSth")
#POST
public Response doSomething(){
//make an action here and set myBean.id value
myBean.id = 'a random value';
}
}
I debugged the code above, but then I realised that inside myBean class, the property "id" was equal to null even though I had set it in the doSomething() method before, is it possible to achieve the scenario described above with these technologies? Before #Inject, I also tried the injection of my managedBean using #ManagedProperty, but the managedBean was null and not injected.
Then I would like this myBean.id property to be changed for the bean when I call it using myBean.id, is that feasible?
Thanks in advance!
Related
I am new to jsf and using JSF 2.0 to keep user information in a session scoped bean. I need to access this information across other beans for grunt work. Presently, this is how i am doing:-
private UserBean myuser1 = (UserBean)FacesUtils.getManagedBean("UserBean");
and then access properties as
if (myuser1.getUserType == 1) ...
this works but some time throws Argument Error: parameter key is null exception. I have been using following method too:-
private UserBean myuser2 = new UserBean();
if (myuser2.getUserType == 1) ...
In second method, my understanding is that if UserBean is already created in session, it would be retried. There are lots of question about 'how to access one bean in another' so i am confused. Please tell me one clean method which should always work and not throw null pointer exception abruptly.
The simplest way I know of is using #ManagedProperty, I don't know what you mean by safest though.
Let's say this is your sessionScoped bean :
#ManagedBean
#SessionScopped
public class UserBean {
//bean attributes and methods
}
Then you can access it in any other bean (provided it has the same or a narrower scope) as an attribute like this :
#ManagedBean
#ViewScoped //in this cas you can use SessionScoped, FlowScoped, or RequestScoped too
public class AnotherBean {
#ManagedProperty("#{userBean}")
UserBean userB;
//rest of the bean
//be sure to add getters and setters for the injected bean
}
For more details check this
Hope this helps.
Actually,
parameter key is null exception: it's either you didn't initialize the object witch can be solver with either adding
object = new Object(); // in the constructor of the class.
The second problem may be that the object is " DETACHED " you need to call the object using the method merge (with the entity manager).
A detached object is a known value but the JPA system doesn't know if it is the latest version from the DB or even sometimes the id value is not set for some reason (Not managed with jpa in other words it can be your case).
If em is your entity manager and you have the following function:
public Object latestVersion(Object o){ em.merge; }
In your Bean with:
#EJB
Service service;
if you do em.latestVersion(o); the problem of detached object is solved.
And for the real answer:
To access a object from another view you can simply do the following.
#ManagedBean
#SessionScoped
..... Bean1 {
public static Object o;
.....
}
#ManagedBean
..... Bean 2 {
private Object b=Bean1.o;
.....
}
Good luck
The standard practice of setting dependency of a scoped bean in another scoped bean is to use #Inject annotation like
#Inject UserBean userBean; in the bean you want use the UserBean object.
Your UserBean should be a stateful one.
#Stateful
#LocalBean
public class UserBean
{
private String name;
public String getName() { return name; }
public void setName( String name_ ) { name = name_; }
}
And just inject it into a stateless bean to modify its state:
#Stateless
#LocalBean
public class MyStatelessBean
{
#EJB
private UserBean userBean;
public String getUserName() { userBean.getName(); };
public void setUserName( String name_ ) { userBean.setName( name_); }
}
Or you can access it from (not wider scoped) managed beans as well in the same way:
#ManagedBean
#Dependent
public class MyJSFManagedBean
{
#EJB
private UserBean userBean;
}
You wrote in your comment you does not use EJBs at all. The picture modify like this:
The UserBean should be a SessionScoped CDI bean
#Named
#SessionScoped
pubilc class UserBean
{}
The othe CDI bean should be in a nearer scope:
#Named
#Request // or #ViewScoped or #Dependent
public class OwnerBean
{
#Inject
UserBean userBean;
}
The container automatically takes care to create the beans in the right scope and insert them into the owers (any kind of container managed objects : servlets, filters, action listeners, JSF/CDI beans). You need to insert a wider scoped resource into a thinner scoped one.
How can I inject a dependency like #EJB, #PersistenceContext, #Inject, #AutoWired, etc in a #FacesConverter? In my specific case I need to inject an EJB via #EJB:
#FacesConverter
public class MyConverter implements Converter {
#EJB
protected MyService myService;
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
// myService.doSomething
}
}
However, it didn't get injected and it remains null, resulting in NPEs. It seems that #PersistenceContext and #Inject also doesn't work.
How do I inject a service dependency in my converter so that I can access the DB?
Can I use #EJB to inject my service into a #FacesConverter?
No, not until JSF 2.3 is released. The JSF/CDI guys are working on that for JSF 2.3. See also JSF spec issue 1349 and this related "What's new in JSF 2.3?" article of my fellow Arjan Tijms. Only then dependency injection like #EJB, #PersistenceContext, #Inject, etc will work in a #FacesConverter when you explicitly add managed=true attribute to the annotation.
#FacesConverter(value="yourConverter", managed=true)
public class YourConverter implements Converter {
#Inject
private YourService service;
// ...
}
If not, what's the "correct" way to do this?
Before JSF 2.3, you have several options:
Make it a managed bean instead. You can make it a JSF, CDI or Spring managed bean via #ManagedBean, #Named or #Component. The below example makes it a JSF managed bean.
#ManagedBean
#RequestScoped
public class YourConverter implements Converter {
#EJB
private YourService service;
// ...
}
And the below example makes it a CDI managed bean.
#Named
#RequestScoped
public class YourConverter implements Converter {
#Inject
private YourService service;
// ...
}
Reference it as <h:inputXxx converter="#{yourConverter}"> instead of <h:inputXxx converter="yourConverter">, or as <f:converter binding="#{yourConverter}"> instead of <f:converter converterId="yourConverter">. Don't forget to remove the #FacesConverter annotation!
The disadvantage is that you cannot specify forClass and thus need to manually define the converter everywhere in the view where necessary.
Inject it in a regular managed bean instead.
#ManagedBean
#RequestScoped
public class YourBean {
#EJB
private YourService service;
// ...
}
And in your converter, grab or call it via EL.
YourBean yourBean = context.getApplication().evaluateExpressionGet(context, "#{yourBean}", YourBean.class);
// Then e.g. either
YourEntity yourEntity = yourBean.getService().findByStringId(value);
// Or
YourEntity yourEntity = yourBean.findEntityByStringId(value);
This way you can keep using #FacesConverter.
Manually grab the EJB from JNDI.
YourService yourService = (YourService) new InitialContext().lookup("java:global/appName/YourService");
The disadvantage is that there is a certain risk that this is not entirely portable. See also Inject EJB bean from JSF managed bean programmatically.
Install OmniFaces. Since version 1.6, it transparently adds support for #EJB (and #Inject) in a #FacesConverter without any further modification. See also the showcase. If you happen to need the converter for <f:selectItem(s)>, then the alternative is to use its SelectItemsConverter which will automatically perform the conversion job based on select items without the need for any database interaction.
<h:selectOneMenu ... converter="omnifaces.SelectItemsConverter">
See also Conversion Error setting value for 'null Converter'.
See also:
How to inject in #FacesValidator with #EJB, #PersistenceContext, #Inject, #Autowired
CDI Injection into a FacesConverter
Getting an #EJB in a #FacesValidator and #FacesConverter
The answer is Yes if you can accommodate Seam Faces module in your web application. Please check this post Injection of EntityManager or CDI Bean in FacesConverter. You can use #EJB in similar fashion.
You could access it indirectly through FacesContext, which is a parameter in both Converter methods.
The converter could be also annotated CDI Named with Application scope. When accessing the facade, two instances of the same class are used. One is the converter instance itself, dumb, without knowing EJB annotation. Another instance retains in application scope and could be accessed via the FacesContext. That instance is a Named object, thus it knows the EJB annotation. As everything is done in a single class, access could be kept protected.
See the following example:
#FacesConverter(forClass=Product.class)
#Named
#ApplicationScoped
public class ProductConverter implements Converter{
#EJB protected ProductFacade facade;
protected ProductFacade getFacadeFromConverter(FacesContext ctx){
if(facade==null){
facade = ((ProductConverter) ctx.getApplication()
.evaluateExpressionGet(ctx,"#{productConverter}",ProductConverter.class))
.facade;
}
return facade;
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
return getFacadeFromConverter(context).find(Long.parseLong(value));
}
...
#Inject will only works in CDI managed instances
This only works at least Java EE 7 and CDI 1.1 server:
#FacesConverter
public class MyConverter implements Converter {
protected MyService myService;
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
myService = CDI.current().select(MyService .class).get();
myService.doSomething();
}
}
https://docs.oracle.com/javaee/7/api/javax/enterprise/inject/spi/CDI.html
https://stackoverflow.com/a/33017416/5626568
By Luis Chacon, Sv
Works fine, tested
definition EJB :
#Stateless
#LocalBean
public class RubroEJB {
#PersistenceContext(unitName = "xxxxx")
private EntityManager em;
public List<CfgRubroPres> getAllCfgRubroPres(){
List<CfgRubroPres> rubros = null;
Query q = em.createNamedQuery("xxxxxxx");
rubros = q.getResultList();
return rubros;
}
}
define bean with the Aplication bean scope, for get the EJB Object
#ManagedBean(name="cuentaPresService", eager = true)
#ApplicationScoped
public class CuentaPresService {
#EJB
private RubroEJB cfgCuentaEJB;
public RubroEJB getCfgCuentaEJB() {
return cfgCuentaEJB;
}
public void setCfgCuentaEJB(RubroEJB cfgCuentaEJB) {
this.cfgCuentaEJB = cfgCuentaEJB;
}
}
final Access to Ejb Object from Converter:
#FacesConverter("cuentaPresConverter")
public class CuentaPresConverter implements Converter {
#EJB
RubroEJB rubroEJB;
public Object getAsObject(FacesContext fc, UIComponent uic, String value) {
if(value != null && value.trim().length() > 0) {
try {
CuentaPresService service = (CuentaPresService) fc.getExternalContext().getApplicationMap().get("cuentaPresService");
List<CfgCuentaPres> listCuentas=service.getCfgCuentaEJB().getAllCfgCuentaPres();
................
I'm trying to use an application scoped bean in JSF2, but for some reason it is always null in my request scoped bean. Here's the code I'm using:
The application scoped bean:
#ManagedBean(eager=true, name="applicationTracking")
#ApplicationScoped
public class ApplicationTracking implements Serializable {
private static final long serialVersionUID = 4536466449079922778L;
public ApplicationTracking() {
System.out.println("ApplicationTracking constructed");
}
}
The request scoped bean:
#ManagedBean
#RequestScoped
public class SearchResults implements Serializable {
private static final long serialVersionUID = 4331629908101406406L;
#ManagedProperty("#{applicationTracking}")
private ApplicationTracking appTracking;
public ApplicationTracking getAppTracking() {
return appTracking;
}
public void setAppTracking(ApplicationTracking appTrack) {
this.appTracking = appTrack;
}
#PostConstruct
public void init() {
System.out.println("SearchResults.init CALLED, appTracking = " + appTracking);
}
}
According to everything I'm seeing in the forums this should work without any other configurations. When I start the server (Tomcat) I'm seeing the ApplicationTracking constructor and init methods getting called.
But in my SearchResults component the printout in the PostConstruct is always null:
SearchResults.init CALLED, appTracking = null
What am I missing?
Provided that you imported those annotations from the right package javax.faces.bean.*, then this problem will happen if you re-registered the very same managed bean class in faces-config.xml on a different managed bean name. Get rid of that faces-config.xml entry. That's the JSF 1.x style of registering managed beans. You don't need it in JSF 2.x. When you do so anyway, then it will override any annotation based registration on the managed bean class, causing them to be ineffective.
Make sure you don't read JSF 1.x targeted resources while learning and working with JSF 2.x. Many things are done differently in JSF 2.x.
I'm probably really close to the solution but I'm new with JSF and I don't see my mistake.
I have a first SessionScoped Managed Bean that represents Business information (address, website, ...)
#Named(value = "businessController")
#SessionScoped
public class BusinessController implements Serializable {
private Business current;
#EJB private BusinessFacade ejbFacade;
....
I have a second SessionScoped Managed Bean that represents the logged in user
#Named(value = "loginController")
#SessionScoped
public class LoginController implements Serializable {
private Login current;
#EJB
private LoginFacade ejbFacade;
#ManagedProperty(value="#{businessController}")
private BusinessController businessController;
public BusinessController getBusinessController() {
return businessController;
}
public void setBusinessController(BusinessController businessController) {
this.businessController = businessController;
}
When a user logs in, I set the current attribute from the loginController
Depending on this current user, I want to set the business attribute from the businessController :
businessController.setCurrent(current.getBusiness());
My problem is that the businessController attribute is null !
I use NetBeans 7.0.1 and GlassFish 3.1
In debug mode, I can see a viewId variable with the value
>No current context (stack frame)<
Unfortunately it doesn't ring any bell to me.
Any help would be appreciated
Thanks
You are mixing JSF managed beans with CDI managed beans.
Your BusinessController is annotated with the CDI annotaion #Named but gets injected with the #ManagedProperty annotation (from JSF). CDI managed beans need to be injected with #Inject. No getter or setter needed in this case. If you tend to use CDI, make sure that you import the correct #SessionScoped:
CDI: javax.enterprise.context.SessionScoped
JSF: javax.faces.bean.SessionScoped
Try the following (After making sure to have the correct scope class imported):
#Inject private BusinessController businessController;
How can I inject a dependency like #EJB, #PersistenceContext, #Inject, #AutoWired, etc in a #FacesConverter? In my specific case I need to inject an EJB via #EJB:
#FacesConverter
public class MyConverter implements Converter {
#EJB
protected MyService myService;
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
// myService.doSomething
}
}
However, it didn't get injected and it remains null, resulting in NPEs. It seems that #PersistenceContext and #Inject also doesn't work.
How do I inject a service dependency in my converter so that I can access the DB?
Can I use #EJB to inject my service into a #FacesConverter?
No, not until JSF 2.3 is released. The JSF/CDI guys are working on that for JSF 2.3. See also JSF spec issue 1349 and this related "What's new in JSF 2.3?" article of my fellow Arjan Tijms. Only then dependency injection like #EJB, #PersistenceContext, #Inject, etc will work in a #FacesConverter when you explicitly add managed=true attribute to the annotation.
#FacesConverter(value="yourConverter", managed=true)
public class YourConverter implements Converter {
#Inject
private YourService service;
// ...
}
If not, what's the "correct" way to do this?
Before JSF 2.3, you have several options:
Make it a managed bean instead. You can make it a JSF, CDI or Spring managed bean via #ManagedBean, #Named or #Component. The below example makes it a JSF managed bean.
#ManagedBean
#RequestScoped
public class YourConverter implements Converter {
#EJB
private YourService service;
// ...
}
And the below example makes it a CDI managed bean.
#Named
#RequestScoped
public class YourConverter implements Converter {
#Inject
private YourService service;
// ...
}
Reference it as <h:inputXxx converter="#{yourConverter}"> instead of <h:inputXxx converter="yourConverter">, or as <f:converter binding="#{yourConverter}"> instead of <f:converter converterId="yourConverter">. Don't forget to remove the #FacesConverter annotation!
The disadvantage is that you cannot specify forClass and thus need to manually define the converter everywhere in the view where necessary.
Inject it in a regular managed bean instead.
#ManagedBean
#RequestScoped
public class YourBean {
#EJB
private YourService service;
// ...
}
And in your converter, grab or call it via EL.
YourBean yourBean = context.getApplication().evaluateExpressionGet(context, "#{yourBean}", YourBean.class);
// Then e.g. either
YourEntity yourEntity = yourBean.getService().findByStringId(value);
// Or
YourEntity yourEntity = yourBean.findEntityByStringId(value);
This way you can keep using #FacesConverter.
Manually grab the EJB from JNDI.
YourService yourService = (YourService) new InitialContext().lookup("java:global/appName/YourService");
The disadvantage is that there is a certain risk that this is not entirely portable. See also Inject EJB bean from JSF managed bean programmatically.
Install OmniFaces. Since version 1.6, it transparently adds support for #EJB (and #Inject) in a #FacesConverter without any further modification. See also the showcase. If you happen to need the converter for <f:selectItem(s)>, then the alternative is to use its SelectItemsConverter which will automatically perform the conversion job based on select items without the need for any database interaction.
<h:selectOneMenu ... converter="omnifaces.SelectItemsConverter">
See also Conversion Error setting value for 'null Converter'.
See also:
How to inject in #FacesValidator with #EJB, #PersistenceContext, #Inject, #Autowired
CDI Injection into a FacesConverter
Getting an #EJB in a #FacesValidator and #FacesConverter
The answer is Yes if you can accommodate Seam Faces module in your web application. Please check this post Injection of EntityManager or CDI Bean in FacesConverter. You can use #EJB in similar fashion.
You could access it indirectly through FacesContext, which is a parameter in both Converter methods.
The converter could be also annotated CDI Named with Application scope. When accessing the facade, two instances of the same class are used. One is the converter instance itself, dumb, without knowing EJB annotation. Another instance retains in application scope and could be accessed via the FacesContext. That instance is a Named object, thus it knows the EJB annotation. As everything is done in a single class, access could be kept protected.
See the following example:
#FacesConverter(forClass=Product.class)
#Named
#ApplicationScoped
public class ProductConverter implements Converter{
#EJB protected ProductFacade facade;
protected ProductFacade getFacadeFromConverter(FacesContext ctx){
if(facade==null){
facade = ((ProductConverter) ctx.getApplication()
.evaluateExpressionGet(ctx,"#{productConverter}",ProductConverter.class))
.facade;
}
return facade;
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
return getFacadeFromConverter(context).find(Long.parseLong(value));
}
...
#Inject will only works in CDI managed instances
This only works at least Java EE 7 and CDI 1.1 server:
#FacesConverter
public class MyConverter implements Converter {
protected MyService myService;
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
myService = CDI.current().select(MyService .class).get();
myService.doSomething();
}
}
https://docs.oracle.com/javaee/7/api/javax/enterprise/inject/spi/CDI.html
https://stackoverflow.com/a/33017416/5626568
By Luis Chacon, Sv
Works fine, tested
definition EJB :
#Stateless
#LocalBean
public class RubroEJB {
#PersistenceContext(unitName = "xxxxx")
private EntityManager em;
public List<CfgRubroPres> getAllCfgRubroPres(){
List<CfgRubroPres> rubros = null;
Query q = em.createNamedQuery("xxxxxxx");
rubros = q.getResultList();
return rubros;
}
}
define bean with the Aplication bean scope, for get the EJB Object
#ManagedBean(name="cuentaPresService", eager = true)
#ApplicationScoped
public class CuentaPresService {
#EJB
private RubroEJB cfgCuentaEJB;
public RubroEJB getCfgCuentaEJB() {
return cfgCuentaEJB;
}
public void setCfgCuentaEJB(RubroEJB cfgCuentaEJB) {
this.cfgCuentaEJB = cfgCuentaEJB;
}
}
final Access to Ejb Object from Converter:
#FacesConverter("cuentaPresConverter")
public class CuentaPresConverter implements Converter {
#EJB
RubroEJB rubroEJB;
public Object getAsObject(FacesContext fc, UIComponent uic, String value) {
if(value != null && value.trim().length() > 0) {
try {
CuentaPresService service = (CuentaPresService) fc.getExternalContext().getApplicationMap().get("cuentaPresService");
List<CfgCuentaPres> listCuentas=service.getCfgCuentaEJB().getAllCfgCuentaPres();
................