I have two Managed Beans:
SessionBean:
#Named(value = "sessionBean")
#SessionScoped
public class SessionBean implements Serializable {
private final Param param
SessionBean(Param param) {
this.param = param;
}
}
and TypesBean:
#Named(value = "typesBean")
#RequestScoped
public class TypesBean {
#Inject
private SessionBean session;
}
The project builds, but does not deploy:
Error occurred during deployment: Exception while loading the app : WELD-001410 The injection point [field] #Inject private com.example.TypesBean.session has non-proxyable dependencies. Please see server.log for more details.
What's the problem?
The problem is the lack of an accessible no-args constructor on the SessionBean class.
One solution as the OP pointed out is:
"The problem was in final methods of SessionBean. Removing final
and making methods just public - solve the problem. Sorry for wasting
your time. "
Or alternatively...
#Named(value = "sessionBean")
#SessionScoped
public class SessionBean implements Serializable {
. . . //variables, setters, getters and other methods
private final Param param
public SessionBean(Param param) {
this.param = param;
}
// no-args constructor used by CDI for proxying only
// but is subsequently replaced with an instance
// created using the above constructor.
protected SessionBean() {
this(null);
}
Related
I'm pretty new to the general procedure of bean injection. I've googled a lot but haven't found a solution to my problem.
Additional Information
Running Wildfly 9.0.1 final
EJB Vers. : 3.1
CDI Vers. : 2.2.16 (SP1)
JSF Vers. : 2.2
import javax.annotation.PostConstruct;
import javax.ejb.Stateless;
import javax.inject.Named;
#Named
#ViewScoped
public class UserEmailSettingsBean extends UserModuleSettingsBean {
private List<String> store;
private List<String> selectedStore;
//getters and setters, some fancy stuff...
#Override
public boolean saveProperties() {
LOG.info("Save called");
LOG.info(selectedStore.toString());
LOG.info(store.toString());
for(String prop : store) {
getProperties().setProperty(prop, String.valueOf(false));
}
for(String selectedProp : selectedStore){
LOG.info("selected: " + selectedProp + ":" + getProperties().getProperty(selectedProp) + " -> true");
getProperties().setProperty(selectedProp, String.valueOf(true));
}
super.saveProperties();
return true;
}
}
2nd Class:
public abstract class UserModuleSettingsBean implements ModuleSettings {
private static final long serialVersionUID = 459417872482285085L;
protected abstract List<String> getPropertiesName();
#Inject
private SettingsRepository settingsRepository;
#Inject
private SettingsService settingsService;
private Properties properties = new Properties();
#Override
public boolean saveProperties() {
String username = SecurityContextHolder.getContext().getAuthentication().getName();
settingsService.store(getProperties(), username);
return (true);
}
}
The problem is, that the settingsService is constructed, however its field "settingsRepository" is null in my child class.
On the call of my save method from UserEmailSettings, getProperties().setProperty() is called with the right values, however its never stored, as the settingsRepository is null. I believe that is due to a wrong Injection for some reason.
Let me know if I need to provide more information ☺
Here is the needed part of SettingsRepository:
#Stateless
#TransactionAttribute(TransactionAttributeType.SUPPORTS)
public class SettingsService implements Serializable {
private static final long serialVersionUID = 1695882717866085259L;
#Inject
SettingsRepository settingsRepository;
//...
}
And here the information SettingsRepository
#Stateless
public class SettingsRepository extends AbstractBaseRepository<Settings, Long> {
/**
* Instantiates a new settings repository.
*/
public SettingsRepository() {
super(Settings.class);
}
}
wanted to say my problem was that I didn't called an init() function on the settingsService to create the propertys, so getProperties was empty
I've the below managed bean
#ManagedBean
#RequestScoped
public class customerBean {
private Customer customer;
private CustomerJpaController customerJpa;
#PostConstruct
public void init() {
customer = new Customer();
}
public String addCustomer() throws Exception {
customerJpa.create(customer);
return "customer";
}
// getter and setter
}
The CustomerJpaController looks like below:
public class CustomerJpaController implements Serializable {
#PersistenceContext(unitName = "JFSCustomerPU")
private EntityManagerFactory emf = null;
private UserTransaction utx = null;
public CustomerJpaController(UserTransaction utx, EntityManagerFactory emf) {
this.utx = utx;
this.emf = emf;
}
// ...
}
When addCustomer() is invoked from the view, it throws java.lang.NullPointerException at line customerJpa.create(customer);. How is this caused and how can I solve it?
In your code sample, your CustomerJpaController is never instantiated. So, you get a null pointer exception.
I advise you to switch to CDI and rely on its injection method to have your entity manager (factory?) properly instantiated and injected in your controller when this last is instantiated. And, so, to use #Named instead of #ManagedBean.
So, you would have :
#Named
#RequestScoped
public class CustomerJpaController implements Serializable {
...
}
(or whichever scope better fits your need)
It seems to me that you should use an EntityManager (EM) rather than an EntityManagerFactory (EMF) in your controller.
If your EMF is container managed and you have only one persistence unit, you can use the standard JPA #PersistenceContext annotation :
#PersistenceContext
private EntityManager entityManager;
If your EMF is not managed, you can leverage the power of deltaspike JPA module (remember : deltaspike is good for you :-) ) and inject an EntityManager in your controller :
#Named
#RequestScoped
public class CustomerJpaController implements Serializable {
#Inject
private EntityManager em;
}
This requires the implementation of an EntityManagerProducer class, which can have any name but must have one method annotated #Produces #RequestScoped returning an EntityManager and another one taking an EntityManager parameter annotated with #Disposes. Ex :
public class MyEntityManagerProducer {
#Inject
#PersistenceUnitName("myPU")
private EntityManagerFactory emf;
#Produces
#RequestScoped
public EntityManager createEntityManager() {
return emf.createEntityManager();
}
public void disposeEntityManager(#Disposes em) {
if (em.isOpen()) {
em.close();
}
}
Note the usage of #PersistenceUnitName("myPU"), the deltaspike annotation that will handle the instanciation of the EMF.
If you have multiple persistence units, as it is often the case in the real world, you can set them apart with qualifiers. To declare a qualifier, declare an #interface with the following annotations :
#Target({ FIELD, METHOD, PARAMETER, TYPE })
#Retention(RUNTIME)
#Documented
#Qualifier
public #interface MyQualifier {
}
Then, add this qualifier to all #Produces, #Disposes and #Inject, to allow CDI to decide which persistence unit / entity manager you are willing to use :
public class MyEntityManagerProducer {
#Inject
#PersistenceUnitName("myPU")
private EntityManagerFactory emf;
#Produces
#MyQualifier
#RequestScoped
public EntityManager createEntityManager() {
return emf.createEntityManager();
}
public void disposeEntityManager(#Disposes #MyQualifier em) {
if (em.isOpen()) {
em.close();
}
}
and in your controller :
#Named
#RequestScoped
public class CustomerJpaController implements Serializable {
#Inject
#MyQualifier
private EntityManager em;
}
All this requires CDI. Configuring CDI is way beyond a short answer to your question. I use OpenWebBeans in all my projects. Weld is also very popular.
This is my understanding of things (it might not be 100% correct but it will give you a general idea) :
Where in your bean is your Service instantiated ? Nowhere. In other words customerJpa is null.
Starting a connection to a db weights a lot on resources. So instead of you instantiating different services by yourself and opening-closing connections, the container has a pool of services and give the free ones to whoever needs it (in your case your bean needs one). How do you ask the container to give you a service :
Annotate #EJB above your service:
#EJB
private CustomerJpaController customerJpa;
and I think you are missing #Stateless as well
#Stateless
public class CustomerJpaController...
It's advised to switch to #Named and #RequestScoped (the other package) instead of #ManagedBean. Then you can use #Inject to inject your service instead of #EJB.here you can read further on the subject.
I wanted to know, is there any option to call a managed bean inside of EJB bean. Imagine, we have the code:
#ManagedBean
#SessionScoped
public class MyManagedBean implements Serializable {
public String getUrl() {
return "http://www.google.com";
}
}
#Stateless
public class MyEJB {
#ManagedProperty(value = "#{myManagedBean}")
MyManagedBean myManagedBean;
public void setMyManagedBean(MyManagedBean myManagedBean) {
this.myManagedBean = myManagedBean;
}
public void call() {
// NullPointerException here
System.out.println(myManagedBean.getUrl());
}
}
I also tried this:
#Stateless
public class MyEJB {
#EJB
MyManagedBean myManagedBean;
...
}
... but it returns different MyManagedBean instance.
This is not right. With CDI managed beans instead of JSF managed beans it's possible, but it is just not right as in, bad design. The business service should not be aware about the front-end at all. It makes the business service unreusable on other front-ends than JSF.
You should do it the other way round. You should inject the EJB in the managed bean, not the other way round. The EJB should be kept entirely stateless. You should just directly pass the EJB the information it needs as method argument (and never assign it as instance variable of EJB afterwards).
E.g.
#ManagedBean
#SessionScoped // <-- Did you read https://stackoverflow.com/q/7031885?
public class MyManagedBean implements Serializable {
private String url = "http://www.google.com";
#EJB
private MyEJB myEJB;
public void submit() {
myEJB.call(url);
}
public String getUrl() {
return url;
}
}
and
#Stateless
public class MyEJB {
public void call(String url) {
// No NullPointerException here.
System.out.println(url);
}
}
See also:
JSF Service Layer
I have a JSF web application with a view-scoped bean and a session-scoped bean. I'd like to modify the session bean's members from the view bean, and I followed this guide from a certain well-known JSF guy, but I can't seem to get it to work without a runtime exception. The reference to the managed session bean, "home" is null when referenced, similar to this question except I've already followed the advice of the accepted answer.
package brian.canadaShipping;
import java.io.Serializable;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ManagedProperty;
import javax.faces.bean.ViewScoped;
#ManagedBean(name= "requestBean")
#ViewScoped
public class CpstcRequestBean implements Serializable {
#ManagedProperty(value="#{home}")
private CpstcHomeBean homeBean;
public CpstcHomeBean getHomeBean() {
return homeBean;
}
public void setHomeBean(CpstcHomeBean homeBean) {
this.homeBean = homeBean;
}
private static final long serialVersionUID = -5066913533772933899L;
public String testVar = "hello world";
private boolean displayOutput = false;
public boolean isDisplayOutput() {
return displayOutput;
}
public void setDisplayOutput(boolean displayOutput) {
this.displayOutput = displayOutput;
}
public String getTestVar() {
return testVar;
}
public void setTestVar(String testVar) {
this.testVar = testVar;
}
public CpstcRequestBean()
{
System.out.println("TEST: " + homeBean.toString());
System.out.println("Hello, ResuestBean!");
}
}
The first bit of my "home" bean is as follows:
#ManagedBean(name= "home")
#SessionScoped
public class CpstcHomeBean implements Serializable {
...
UPDATE: I've followed Jordan's suggestions and I have the following in my view-scoped bean:
#ManagedBean(name= "requestBean")
#ViewScoped
public class CpstcRequestBean implements Serializable {
#Inject #Named("home") CpstcHomeBean homeBean;
public CpstcHomeBean getHomeBean() {
return homeBean;
}
public void setHomeBean(CpstcHomeBean homeBean) {
this.homeBean = homeBean;
}
public CpstcRequestBean()
{
System.out.println("TEST: " + homeBean.toString());
System.out.println("Hello, ResuestBean!");
}
...
as well as this in my session-scoped bean:
#Named("home")
#SessionScoped
public class CpstcHomeBean implements Serializable {
...
yet my "home" bean reference is still null. Any ideas?
UPDATE 2: It turns out that you must use #Named in both classes, not just the injected class. My web app now loads but some elements are blank. In my console log, I see, "Target Unreachable, identifier 'home' resolved to null." I'm running on Tomcat 7, if that affects things. Any ideas?
You can either change your session bean's #ManagedBean to #Named and then just inject it into your view scoped bean OR you can reference the session bean as is like this:
FacesContext fc = FacesContext.getCurrentInstance()
private CpstcHomeBean homeBean = (CpstcHomeBean) fc.getApplication().evaluateExpressionGet(fc, "#{home}", CpstcHomeBean.class);
I searched similar questions but I'm a bit confused. I have a login page, so LoginBean also which is;
#ManagedBean(name = "loginBean")
#SessionScoped
public class LoginBean implements Serializable {
private String password="";
private String image="";
#ManagedProperty(value = "#{loginBeanIdentityNr}")
private String identityNr="";
...
after success, navigates to orderlist page, so I have also OrderBean.
#ManagedBean(name = "OrderBean")
#SessionScoped
public class OrderBean {
List<Ordery> sdList;
public List<Order> getSdList() {
try {
String identityNr ="";
ELContext elContext = FacesContext.getCurrentInstance().getELContext();
LoginBean lBean = (LoginBean) FacesContext.getCurrentInstance().getApplication().getELResolver().getValue(elContext, null, "loginBean");
identityNr =lBean.getIdentityNr();
sdList = DatabaseUtil.getOrderByIdentityNr(identityNr);
...
}
I don't need the whole LoginBean, just ManagedProperty "loginBeanIdentityNr". But this code below doesn't work (of course);
identityNr = (String) FacesContext.getCurrentInstance()
.getApplication().getELResolver()
.getValue(elContext, null, "loginBeanIdentityNr");
this time it returns null to me.
I think if I need whole bean property, I can inject these beans, right? So, do you have any suggestions for this approach? can<f:attribute> be used?
The #ManagedProperty declares the location where JSF should set the property, not where JSF should "export" the property. You need to just inject the LoginBean as property of OrderBean.
public class OrderBean {
#ManagedProperty(value="#{loginBean}")
private LoginBean loginBean; // +setter
// ...
}
This way you can access it in the OrderBean by just
loginBean.getIdentityNr();
Alternatively, if you make your OrderBean request or view scoped, then you can also set only the identityNr property.
public class OrderBean {
#ManagedProperty(value="#{loginBean.identityNr}")
private String identityNr; // +setter
// ...
}
Unrelated to the concrete problem: initializing String properties with an empty string is a poor practice.