I'm running an enviroment with JSF + Primefaces + tomcat 6.0.32 in netbeans using EclipseLink (JPA 2.0).
My application works fine, but everytime I run it, I get a lot of warnings saying that cannot Serializate my session beans, and shows me blocks like this for every session bean:
18-jul-2012 23:05:46 org.apache.catalina.session.StandardSession writeObject
ADVERTENCIA: No puedo serializar atributo de sesión facturacionController para sesión 62A53325838E1E7C6EB6607B1E7965E6
java.io.NotSerializableException: org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1164)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1518)
... and so on...
The thing is that my session beans already implements Serializable.
So what can I do to solve this ?
Thanks !
---- added info 07/20/2012 ----
The only point where I'm making a reference to EntityManager from the session bean is when I create the jpaController in the getter property, like this:
private JpaController getJpaController() {
if (jpaController == null) {
jpaController = new JpaController(Persistence.createEntityManagerFactory("myPersistenceUnit"));
}
return jpaControllerPedido;
}
That is because I defined the jpaController constructor like this:
public JpaController(EntityManagerFactory emf) {
this.emf = emf;
}
Making a class Serializable does not means everything in it will be serializable. All references(dependencies/properties) in your class, they themselves should be serializable and in turn their references.
As per above exception it seems your session bean is having reference to EntityManagerFactoryImpl object which is not serializable and hence the error.
To solve this you can define it as transient than it wont be serialized but only problem will be during de-serialization you will have to build the object or assign reference manually.
I suggest have a look at this article on Serilization.
How to solve this, I don't do JPA so cannot tell if there is some serialized class for same,
To solve it define the reference as transient
transient EntityManagerFactory entityManagerFactory
and assign the reference back to bean manually in deserialization hook method as described below.
private void readObject(java.io.ObjectInputStream stream)
throws java.io.IOException, ClassNotFoundException
{
stream.defaultReadObject();
// assign reference manually.
this.entityManagerFactory = //get from factory;
}
Hope this helps !!!!
You only add this:
transient EntityManagerFactory entityManagerFactory;
But if have any other Object that implement entityManagerFactory, this object must also be defined as. For Example
transient static final EntityManagerFactory emf = Persistence.createEntityManagerFactory("porpertiesConexion");
transient EntityManager em;
public void beginTransaction() {
em = emf.createEntityManager(); //
//code....
}
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.
I'm beginning with JSF (Mojarra 2.2 and Glassfish 4) and currently practicing with a web application which job is to store Clients and their Orders in DB.
When creating a new Order, one feature is to allow choosing an existing client from a JSF <h:selectOneMenu>. An Order entity stores a Client entity among other attributes...
I've followed BalusC's great answer about prepopulating a <h:selectOneMenu> from a DB (here), and have successfully populated mine from data stored in an eager ApplicationScoped ManagedBean, but I can't manage to retrieve the selected item in the backing bean as complex object. It is always null.
This is driving me mad and your help will be truly appreciated!
Here are the relevant code snippets:
#ManagedBean(eager = true)
#ApplicationScoped
public class Data implements Serializable {
private static final long serialVersionUID = 1L;
#EJB
private ClientDao clientDao;
private List<Client> clients;
#PostConstruct
private void init() {
clients = clientDao.lister();
}
public List<Client> getClients() {
return clients;
}
}
Order creation bean (note: 'commande' means order ;)
#ManagedBean
#RequestScoped
public class CreerCommandeBean implements Serializable {
private static final long serialVersionUID = 1L;
private Commande commande;
private String choixNouveauClient = "nouveauClient";
#EJB
private CommandeDao commandeDao;
public CreerCommandeBean() {
commande = new Commande();
}
public void inscrire() {
System.out.println("client : " + commande.getClient()); // prints **NULL**
// ... orderService to store in DB
}
... getters and setters
Client converter:
#FacesConverter(value = "clientConverter", forClass = Client.class)
public class ClientConverter implements Converter {
#Override
public Object getAsObject(FacesContext context, UIComponent component, String value) {
if (value == null) {
return null;
}
Data data = context.getApplication().evaluateExpressionGet(context, "#{data}", Data.class);
for (Client c : data.getClients()) {
if (c.getId().toString().equals(value)) {
return c;
}
}
throw new ConverterException(new FacesMessage(String.format("Cannot convert %s to Client", value)));
}
#Override
public String getAsString(FacesContext context, UIComponent component, Object value) {
return (value instanceof Client) ? String.valueOf(((Client) value).getId()) : null;
}
}
Facelet excerpt:
<p:outputPanel id="gridContainerAncienClient">
<p:selectOneMenu value="#{creerCommandeBean.commande.client}"
rendered="#{creerCommandeBean.choixNouveauClient == 'ancienClient'}">
<f:converter converterId="clientConverter" />
<f:selectItems value="#{data.clients}" var="cli"
itemValue="#{cli}" itemLabel="#{cli.prenom} #{cli.nom}" />
</p:selectOneMenu>
</p:outputPanel>
CreerCommandeBean is #RequestScoped. That means it will live only for one request.
When you select a client to be assigned to #{creerCommandeBean.commande.client} you do this by a request. #{creerCommandeBean.commande.client} is now the selected client. Then the request is over, the bean gets destroyed and your "changes" are lost.
When you try to retrieve that data, you do that by a request again: A new instance of CreerCommandeBean is created and the constructor assigns the property commande with a new instance of Commande whose property client again is probably null.
Solution:
Use a broader scope. e.g. #ViewScoped which makes the bean "live" as long as you stay in the same view - no matter how many requests you make.
Tip:
Read BalusC's Post on Communication is JSF 2.0. Parts might be slightly different in JSF 2.2 but it's still a good and comprehensive introduction.
I got stuck with similar problem, only to realize that I forgot to implement equals() and hashCode() method in my Object. Client Class in this case.
I should blame myself for skipping the instructions in BalusC's blog.
"...Please note the Object#equals() implementation. This is very important for JSF. After conversion, it will compare the selected item against the items in the list. As the Object#equals() also require Object#hashCode(), this is implemented as well...."
I would like to rollback transaction not inside EJB but inside JSF managed bean. Inside EJB we can use SessionContext.setRollBackOnly() but what can I use in managed bean ?
#Stateless
#Local(AccountLocal.class)
public class AccountBean implements AccountLocal {
public void test1() throws CustomException(){
...
}
public void test2() throws CustomException(){
...
throw new CustomException();
}
public void test3() throws CustomException(){
...
}
public void all() throws CustomException(){
test1();
test2();
test3();
}
}
In my managed bean :
#SessionScoped
public class LoginBean implements Serializable{
public void test(){
try{
accountBean.test1();
accountBean.test2();
accountBean.test3();
}catch(CustomException e){
// WHAT HERE TO ROLLBACK TRANSACTION ?
}
}
}
EDIT : How can I ensure that if one of the test1, test2 or test3 rolls back, others will roll back too ?
I tested this code and accountBean.test1(); is validated even if accountBean.test2(); rolls back.
Could the solution be only to nest this 3 methods inside one EJB method ?
#SessionScoped
public class LoginBean implements Serializable{
public void test(){
try{
accountBean.all();
}catch(CustomException e){
...
}
}
}
Transactions are automatically rolled back by the EJB container if an unchecked exception is thrown (note that JPA's PersistenceException is such one). Your CustomException seems to be a checked exception. If changing it to extend RuntimeException as follows
public class CustomException extends RuntimeException {
// ...
}
or creating a new one is not an option, then you need to set the #ApplicationException annotation on the class with the rollback attribute set to true.
E.g.
#ApplicationException(rollback=true)
public class CustomException extends Exception {
// ...
}
Please note that the concrete problem has nothing to do with JSF. The service layer and managing transactions is completely outside the responsibility of JSF. It's the responsibility of EJB instead. JSF should merely act as "view" in this perspective.
See also:
JSF Service Layer
Handling service layer exception in Java EE frontend method
I'm playing the Devil's advocate here, since BalusC's advice that you should not let your backing beans act as services is absolutely true.
But, purely as a technical excersise, it -is- possible to start a JTA transaction in a backing bean and then control start and commit or rollback programmatically.
You can do this by injecting a UserTransaction via #Resource. Prior to calling your EJB methods, call start on this instance, and after the last call either commit or rollback.
Again, this is a purely theoretical answer. In practice, don't do this and let the backing bean call 1 EJB method that calls out to other EJB beans if needed.
I have a navigation managed bean for each user.
and I need it to initialize first before any other bean because a value is required from the bean.
May I know how do I perform that?
I have tried eager="true" but it doesn't work.
any quick and easy solution via faceconfig would be greatly appreciated.
Just perform the desired initialization job in bean's #PostConstruct.
#PostConstruct
public void init() {
// Here.
}
It'll be invoked when the bean is injected/referenced from another bean for the first time.
The eager=true works only on application scoped beans.
From what I see you should reference the other bean. Let's assume a have a utility class that can pull a bean from the context.
Basically ->
//Bean A
public void doSomething()
{
String required = Utility.getBeanB().getRequiredValue();
use(required);
}
...
//Bean B
public String getRequiredValue()
{
return "Hi, I'm a required value";
}
I have several large web apps that have a "Session Bean" that stores stuff like user preferences, shared objects etc... and this method works perfectly. By using a reference to the bean you eliminate the need to chain the initialization. That method will always DEPEND on the method in the other bean, thus guaranteeing the order of initialization.
There's a variety of ways to access the bean but I usually go through the EL route ->
Get JSF managed bean by name in any Servlet related class
Best of luck, I try to stay "functionally pure" when I can--and I hope that get's a laugh considering the language!
Here's some cool hax for ya, in case other solutions aren't working for you due to various circumstances...
Let's say I have a class Alpha that I want initialized first:
public class Alpha {
#PostConstruct
public void init() {
}
}
I can put the following method in Alpha:
#ManagedBean(name = "Alpha", eager = true)
public class Alpha {
public static void requireAlpha() {
FacesContext context = FacesContext.getCurrentInstance();
Object alpha = context.getApplication().evaluateExpressionGet(context, "#{Alpha}", Object.class);
System.out.println("Alpha required: " + alpha.toString());
}
#PostConstruct
public void init() {
}
}
Then, in any classes that are initializing too early, simply call:
Alpha.requireAlpha();
// ...
// (Code that requires Alpha to be initialized first.)
And if there's a ChildAlpha class that extends Alpha that you really want to be initialized (rather than the parent), make sure to use "ChildAlpha" instead, in both the name="" and the EL Expression ("#{}").
See here for more infos: Get JSF managed bean by name in any Servlet related class
I am using PrimeFaces UI library and JSF 2.
I have a backing bean:
public class JobMgmtBean extends ClientBeanBase implements Serializable
and
public class ClientBeanBase extends BeanBase
(so inheritance is JobMgmtBean:ClientBeanBase:BeanBase).
I wanted to set my JobMgmtBean from request scoped to view scoped, but after a while my sessionVars which is defined in BeanBase becomes null and the bean is not functional anymore.
I initialize sessionVars in the BeanBase like this:
protected Map<String,Object> sessionVars = null;
ex = FacesContext.getCurrentInstance().getExternalContext();
sessionVars = ex.getSessionMap();
I refresh some of my PrimeFaces UI components on the page every 5 seconds (using <p:poll interval="5"...>), and after a few refreshes sessionVars becomes null.
Why does this happen?
You can use View scope provided you can assemble the state of object during de-serialization.
Java provides method hooks for a serializable class where you can perform custom logic.
private void writeObject(java.io.ObjectOutputStream stream) throws java.io.IOException {
//custom logic
stream.defaultWriteObject();
}
private void readObject(java.io.ObjectInputStream stream) throws java.io.IOException, ClassNotFoundException {
stream.defaultReadObject();
// custom logic
}
Any bean reference you think you dont want serialize you can mark it as transient.
private transient Bean bean.
this bean wont get serialized but the problem is you are responsible
to set the reference back when it is deserailized in method hook
"readObject"
private void readObject(java.io.ObjectInputStream stream) throws java.io.IOException, ClassNotFoundException {
stream.defaultReadObject();
// custom logic
this.bean = ................
}
ViewScoped beans require objects to be Serialized, and my class extends many classes with too many object which all need to be Serialized which is not possible. This means that I can not use ViewScoped at all here.